External Wall Insulation ~ The Ugly Truth?

[@snowman2970]

I was a property manager and we decided to EWI a whole estate of 1920`s solid brick houses which were suffering with excessive damp and mould (also the properties externally were looking old and quite depressing) We specified that any obstructions to the insulation must be removed and insulated 100% of the external walls. It was a huge success resolving years of problems as well as modernising the appearance. That was 25 years ago and driving past recently I noted that the properties are still looking really good.

[@GerryMcglynn]

Sir, i am thinking about getting this installed, is this gentleman correct in what he is saying. 😮 😮 😮

[@snowman2970]

@@GerryMcglynnYes he is. To fit the external insulation correctly and prevent cold bridging the entirety of the insulated wall had to be cleared of any water downpipes, fence posts existing window/door sills and then extended or refitted over the new insulation including the removal of any lean to/conservatory structures. If the the existing roofs are flush finished with the walls the roof coverings would also be extended to cover the new cladding (mostly at gable ends)

[@lordprotector3367]

Bet it looked awful, though.

[@Dave5843-d9m]

It’s been done to some horrible 1950s flats in Paignton Devon. Not cheap but they look MUCH better and residents say they are now really nice to live in.

[@GerryMcglynn]

Sir, i am getting my bungalow done soon is there any thing that i should look out for, i know nothing about the building trade, was a Chef for most of my working days. Thanks 👏 😊 🫂 🙏.

[@jamesjjmilly]

Great video, thanks. I’m an Architect and fitted external wall insulation to my 1929 house 8 years ago. I did it at the same time as a major extension and rebuild which avoided most of the problems. Fortunately because of that I haven’t had any issues with condensation or mould. We doubled the size of the house and halved our heating bills. More importantly we have a lovely warm and draft free house which is very good for my wife’s arthritis.

[@jackdeniston59]

Dehumidify cost?

[@tibiavram]

Normally you shouldn't use polystyrene on a brick wall. Even if it's more expensive (+30-40%) use bazaltic wool.

[@mnomadvfx]

Doubled the houses size with a single extension? Damn, that's gotta have been expensive. I guess the insulation will eventually pay for part of that in saved heating costs, but that is still a sizable cost to bear unless the house was already pretty small to begin with.

[@knezag4798]

@@tibiavram It is again covered with polyester mesh and an acrylic low vapor permeable facade. Apart from the greater thickness and the price required for insulation with hard mineral wool, the effect is usually similar or worse due to the lambda coefficient of satisfying the thickness of the thermal insulation and the savings that people resort to.

[@knezag4798]

@@jackdeniston59Good question !

[@vinnysurti]

Nice to see you are insulating your thumb 👍🏽

[@American-In-Mykolaiv]

A craftsman who actually works will, at times, do some damage to his/her thumbs and fingers.

[@ricos1497]

@@American-In-Mykolaiv An office worker who actually works will, at times, sleep with a married colleague.

[@playerone82]

Lol 👍🩹

[@johnnorris1983]

We need fresh air to breathe. We need ventilation. We need warmth.. Compromise creatively

[@reaper060670]

GREAT videos Roger mate.. I gotta say the energy that comes off the screen is brilliant. I used to work with a guy one day a week who was a master decorator if there is such a thing. He did the rag rolling and all these beautiful paint effects, Artexing ceiling with crazy designs and u remind me of him. It was 25 yrs ago mind when I lived in Croydon.. Man I miss the lingo from there. I'm enjoying the info on the videos too BTW Roge mate. My brother is called Roge too and he lives in London atm at the behest of Her Majesty Prison service... LMAO.. He's an 'eejit'.. That's the Irish wax of sayin' 'idiot'.

[@SergeyPRKL]

Finnish housebuilder here. This is so very true. Nice and simple explanation how it works.

[@MrGuardcaptain]

After 48 seconds i already want to elect Roger as PM. Well said.

[@m4inline]

Was going to say the same thing. Used to think Roger as PM and Clarkson for transport but now I think Clarkson should do farming too.

[@ksmith7122]

I've got a few flats with EWI. No issues with moisture at all. Soil stacks are plastic, boiler flues obviously warm enough, and no issues with damp or mould anywhere. If the EWI did anything it got rid of damp on inside walls that was there before and made the flats so warm that heating is no longer required. Nothing but good things to say about EWI. Tenants love it when they hear there are low or no heating bills, especially with the cost of living crisis. Recommended.

[@ksmith7122]

@user-ep3iv1pc8k no grant. Was fitted by a company from Glasgow that specialise in this. Worked out about £7,000 per flat so not cheap.

[@ksmith7122]

Company was called SkyForm

[@whirled_peas]

If moisture has gone down after installing, you had damp ingress through the walls.

[@ksmith7122]

@@whirled_peas pls explain

[@mktrollop1093]

We bought our house around three years ago, black mould all over the inside walls and absolutely sopping with moisture. solid concrete and small so only possibility was to do ewi, they give a 6k grant here in Ireland to do it, absolutely great job, but because we had just bought the house I was able to take absolutely everything off it, got new windows in and mounted them flush with the exterior face of the original wall, had to put a meter cabinet in as power was coming in onto gable of the house, do I left meter cabinet proud 110mm. Got the insulation done, and it absolutely transformed the house, no cold spots at all. What did happen though is all my moisture flecked off into the attic and I had mouldy patches where all the rafters were coming down to the top of the walls. Cored a couple of holes in each gable and made sure I was getting ventilation through my soffit, attic absolutely bone dry now and not a patch of mould anywhere, also added benefit of ewi is the thermal mass of the walls gets put to use, house stays warmish for a good three days with no heating on now.

[@ItsFriscoBaby]

House stays warm for 3 days because the solid wall is a giant storage heater. You heat the wall and the external insulation traps the heat in it. It's not a bad thing but internal wall insulation would have been better.

[@mktrollop1093]

@@ItsFriscoBaby I know.. Thats what I said..., and that's what makes it great. Insulated dry liner wouldn't have worked, and would have caused huge thermal bridges at the junctions between internal walls and external walls causing mould, also would have made the small rooms unusable.

[@tomschevette]

Do you remember what the grant is called. I live in Ireland and trying to insulate my mum's house as there is nothing but the dry line I've done inside the old house but the extension as nothing in the walls just attic space is insulate.

[@mktrollop1093]

@@tomschevette home energy upgrade grant I think, specially for ewi. We got in just in time though because to qualify now you need to achieve a BER of B or better I think, so basically the only option is the deep retrofit grant for older houses. Load of bollox as it just puts any improvements out of reach of alot of ordinary people.

[@tomschevette]

@@mktrollop1093 thanks I'll have a look into it. No surprise they changed it don't want to pay out 😂

[@ianworley8169]

I worked in social housing for almost 20 years. Black mould and condensation was the bane of every repair officer's life. Even when we'd insulated the stock, installed the most efficient condensing boilers and double glazing, some tenants still suffered from condensation and black mould. Often, you'd have two adjoining houses, one mould free, the other full of mould. Regardless of the witch hunt in the tabloid press, it's mainly a lifestyle issue. Cooking with pan lids off, not using extractors in bathrooms and kitchens, drying clothes on racks and radiators, not opening windows to vent a bathroom after use, or using the heating to avoid cold surfaces. Most often, black mould is directly related to poverty. When all else failed, I found one product was amazing in removing internal moisture laden air to avoid condensation and mould growth. It was the Nuaire Drimaster (for houses) and Flatmaster (for apartments). They extract continuously and use incredibly low amounts of electricity. My own parents bought a bungalow which had terrible mould growth behind wardrobes and on external walls. I installed a Drimaster in their hall ceiling and it immediately resolved the problem. I'm not making some marketing pitch on their behalf, but on this I'm absolutely certain. No other humidistat or extractor came close. They are absolutely brilliant. They're not cheap to buy, costing £300-400, but I've never seen anything work better. They're ridiculously cheap to run, literally a few pence per day and are silent.

[@SkillBuilder]

Ian I agree with every word of your comment.

[@mnomadvfx]

"Cooking with pan lids off, not using extractors in bathrooms and kitchens, drying clothes on racks and radiators, not opening windows to vent a bathroom after use, or using the heating to avoid cold surfaces" Or not opening a window when you boil a kettle. And ye - even with an extractor fan vent I have noticed that my dads bathroom still feels/smells wrong simply because he seems to be allergic to opening the window in that room despite being fine with opening them everywhere else.

[@BigBlueRabbit]

Thanks for this advice

[@andrewcochrane6994]

My daughter used to let properties to high-net-worth customers in London. Despite them paying eye-watering levels of rent and presumably being very well educated my daughter repeatedly had to give them a simplified variation of this presentation after their lifestyle issues led to mould infestation. Open a window, don't dry your washing on the radiators, use your exactor fan and if need be, get a dehumidifier. Unfortunately, I have even met architects who are basically clueless about the physics of dwellings. People are always suggesting things schools ought to be teaching, this one is one my list. Likewise, the building trade needs to change, once you start insulating to this level, detail really matters so we need a whole new generation of builders who won't compromise on their standards and will quote regulations and advisories back at customers who want the cheap and the quick and politely say, sorry mate that's above my pay grade, plenty of good work without messing around with unsafe solutions that will bring problems down on my head later.

[@Daniells1982]

The Nuaire Drimaster isn't an extractor it's a PIV unit. It's putting filtered air from outside in, not extracting air out.

[@KevinLyda]

One of the first retrofits I did was install heat recovery ventilation. It made my house less drafty, helped keep my heat and improved indoor air quality. Insulation is great, but ventilation is key.

[@AA-iq6ev]

Yes ventialtion is the key for longivity of the hoouse and the people inside it :)

[@billjane5522]

Would never have a house without this, makes a huge change to air quality and comfort.

[@dimitritzer5028]

are there any companies/modules you would reccomend?

[@geofftheakstone2152]

both go hand in hand

[@buca9696]

Wow, i never knew that fancy ventilation seals the house.

[@freddieqmercury5961]

In Canada, with new build homes, we have to install air exchangers, so as to manage the moisture issues. I used to go on house calls with people in older updated insulated homes and they would complain about moisture on their new windows. I had to explain that they had made their homes more airtight and that the house needed to breathe. One couple were upset with one another sash having moisture and the one next to it had none, I explained that the fly screen was trapping moisture, they removed the screen and shortly after the moisture evaporated. You are correct, making your house more airtight, needs some attention to air flow control.

[@what.if.youre.wrong...]

As an expat, the UK don't use air conditioning as standard, the climate is so mild they 'get away' with a total misunderstanding of 'Building Science', so they don't get 'vapour permeability'. They need to listen to Joe

[@454Casull]

Having better windows would help. It only happens because the interior humidity is able to condense on the windows. I can understand wanting to have less-dry air during wintertime, and it sucks that windows, almost by their nature, are not very good at keeping out the cold.

[@andyjonessplatoon0192]

Hi there. I work doing ewi and yes we do have a plumber that moves the pipes . We do take the fence or gate post from the walls that’s my job. Yes I am a carpenter. We rebuild from new the fence and gates that we remove . We do on some properties work with wales and west utilities to move same gas boxes and insulation is behind. Sorry we do move most things and put them all back when it’s finished. I hope this explanation is good for you and keep up your good work as I always enjoy your videos and I hope your thumb gets better .👍👍👍

[@goygoyim6443]

And tom jones was also black..

[@SkillBuilder]

That is good to hear but it is, by no means, typical.

[@sivakumars1712]

Very accurate

[@smallfeet4581]

​@@goygoyim6443 what ?, get off , this channel is about house insulation , and no he wasn't , they did a family tree , but so what if he was

[@sivakumars1712]

Thanks. I learnt a lot from your video and the 700 odd comments too.

[@klang180]

Good on the technicals, terrible on the politics. People like insulate Britain are putting themselves out there and are vilified to the extreme. Even if you don't believe in their methods you do believe they have a point and the government is not helping anyone. We must stand up for each other and not just do the bidding of the powerful for them i.e call brave, principled people 'idiots'. Saying that if they do insulation they look that are 'caving in' is ridiculous as they'll never do it without any pressure, no government has ever given anything without a fight. It's thanks to protesters that we have weekends, the vote, women's suffrage, holidays etc. Stand by your fellow average person don't just do what you're told by the Murdoch's and Morgan's of the world.

[@jammybarsteward593]

Brilliant video and explained really well, neighbour is having the mould problem and his solution is EWI, will show him this video before he starts.

[@1982nsu]

Hello Roger from a GC across the pond. Great video. It's important for people to understand that there are no singular silver bullet solutions. All solutions need to be comprehensive. You explained it well.

Roger, you are an absolute legend! This sort of education is soo important for us the general public, so we can understand the why and how, so simply we can toggle the new found issues after isolating our houses! Thank you for doing all this! Adrian from Austria! Have a great day!

[@joegatrill6634]

I insulated my solid wall house 4 years ago. Although there are no cold bridges, it definately gets more humid. If that moist air makes it into the loft it condenses on the roof and drips down. I've put a lot more ventilation in my loft and try and do regular air changes. Getting rid of cooking and shower moisture at source is important too. It has been brilliant on the whole, during cold weather the outside of my house has ice crystals in it as the heat loss is so low!

[@darkknight17]

Hello mate, did you insulate internally or externally?

[@joegatrill6634]

@@darkknight17 externally.

[@Chief81]

Would you say it made your house a lot warmer in winter?

[@joegatrill6634]

@@Chief81 It's night and day compared to before. We could never get the house warm before. it would be freezing again within an hour of turning the heating off. Now we run the heating for an hour and it's warm for hours. We did have old aluminium windows before too.

[@Chief81]

@@joegatrill6634 sounds like my house 😅, 1930’s ish detached house no cavity wall. Freezing in winter when heating is not on & heat disappears rapid after turning it off. Considering having this done dependent on price of course.

[@alexrezel8860]

Flamboyant delivery of reasonable approach. Unusual combination.

[@carpenteire]

Well done Roger, as someone who works in the construction industry I appreciate your commentary. This whole area is fraught with risk if the principles at play are not understood and you explain the building science extremely well!

[@SkillBuilder]

Thanks Marc

[@garywheeley5108]

@@SkillBuilder hi Roger could you say in layman's terms how much in £ at todays money how much energy you would save by ewi ground source heat recovery taking into account installation cost running costs maintenance suitability for various types of construction because to me it seems there is at best a very small benefit if at all in retro fitting this ....

[@timhancock6626]

@@garywheeley5108 That's an impossible ask. The first thing to do is a heat loss calculation on the property as it is. That's not expensive or particularly difficult and will inform you as to where your money is best spent first. As to whether the measures you list are worth doing depends on your aims, which could be comfort, saving money ( which is contentious and may rule out some measures) or reducing carbon footprint. I think you have to decide what it is you want, and how far you can afford to implement those measures. In general Return on Investment may be something you are unlikely to see, depending on your age, and depending on how much capital you spend.

[@clooperman3745]

@@SkillBuilder Very interesting video as usual, l have not seen this type of insulation method before but did work on a project around 35 years ago for the local council that involved applying insulated plasterboard to the internal walls of 4 storey blocks of flats, the job was a nightmare for the tenants due to the major disruption but at the time it was the only solution to the problem.

[@cliveawilson]

Thanks Roger - great video and fabulous presentation style.

[@ellie_5276]

Fantastic video - thank you for taking the time to explain the pitfalls of non-optimal EWI installations!

[@buddywhatshisname522]

Good information, thank you. I’m on a small island off of the west coast of British Columbia Canada (yes, my father was a lumberjack)… I have been considering external insulation for a while and this helps.

[@MiniLuv-1984]

Roger, Roger, Roger...you should thank those that take action and if you think they don't understand educate them like you did here with this video, insulting them will only alienate them. That was magnificent and clear explanation, thank you kind sir.

[@SkillBuilder]

I talk to them whenever I can and listen to their views. Most of the time the arguments don't stack up. If they can't take a few harsh words they are not cut out for protesting. I get loads of stick all the time and I deserve it, just like anyone who sticks their head above the parapet. I would argue with the phrase 'take action' is mostly inaction, lying down in the road and they got their how?

[@MiniLuv-1984]

@@SkillBuilder Yes, half truths and stupidity in a blender. People can see a problem and want to take action but without sound, facts based information, they do the next best thing - wing it.

[@giovannip.1433]

Unless you live in an extremely hot or cold climate installing external wall insulation costs more than what you are trying to save. You don't have to live in a 22 degree air conditioned home. Mold is more dangerous than a 15 degree C home. Ceiling and floor insulation does the majority of the work. Many people don't understand or know how to manage an old home. They don't know that 'mum n' dad' used to wipe the condensate from the windows in the morning, open up the windows to let fresh air in and send the 5 kids out to play in the cold. People have become soft and ignorant...

[@giogio4833]

100% fact

[@giovannip.1433]

@fowyb Not saying improvements aren't required. Case by case basis. You live in swampland you build a house on stilts - but don't tell everyone around the world to do the same regardless of climate.

[@radu1042]

My first labourer job was doing just that. Can't remember if we moved the gas meter, but everything else was moved to enable us to board the whole house. The scheme changed the windows and put new window sills. Was done very well.

[@ram64man]

Totally agree - I brought a 1970s build with empty cavity as part if the huge renovation we decided to have both internal and external insulation fitted to lower energy requirements , great until you realise the humidity increase. First off regarding flue and soil pipes prior to arrival and because it wasn’t occupied, the soil pipe and glue were extended. For the flue it ment getting a gas engineer in to size one up and cut to the new length needed. This one was easy since we were Also fitting a new system boiler , with the external soil pipe removal and extending was essential or it would have to have a larger box section fitted , but thankfully we had a fitter who was happy to work with the team so they could pre cut to size , but there’s little to do about fitting around the sewer inlet other than to fit a box with the internal insulation plug sockets or new outlets must be planned and run , but we still had to retrofit a new heat exchanger in the dining room /living room . The kitchen extractor on when cooking and washing up and a green room dehumidifier 8kwh running plumed in , this fills up a 10 litre in about 4 days when people stay and sleep over . I was thinking of a house hvac exchanger but retrofitting now is Awkward now that second fit onwards so please plan ahead if you plan on doing the same also when having air tightness talks for external find out what they are using to close the gaps or if they fit external edging on these sheets like internal rated for , trust me you can’t get a good fit with a saw no matter what they say , it’s no say labour job it needs planning and working well on site it took a week to do everything external to get it all in . And it’s not cheap to do this 5 bedroom cost 18,000 external and 9 k for inside . For a team of 3 , plus Plummer and gas engineer. And please don’t forget to super insulate your cold feed it’s a condensate magnet otherwise

[@bobbyjonkey13]

I worked for 25 yrs doing EIFS as Journeyman plasterer and Foreman here in the southeast USA .. You can also do a lot of intricate trim work with it. when it is properly done it lasts a long time. great insulation and some very excellent looking buildings.

[@dgbeans]

Great informative video ! The problem with the EWI system is that the installation specifications from the manufacturer's do not specify ventilation. You can insulate your way in to a condensation issue as the humidity in the building is trapped. If you insulate you should also ventilate but most installers and home owners cover up there vents. If done properly EWI is a great way to keep the property warm in the winter, cool in the summer and can reduce energy bill's also co2 footprint. The point at where condensation forms is called a dew point and generally the coldest surface in each room. I use a non mechanical ventilation air brick called an ultravent and we have never had any issues. Hope this comment can help anyone considering having EWI 👍

[@karlovuk]

Thanks!

[@SNORKYMEDIA]

had ours done 5 or so years ago and have none of these "issues", it has dramatically reduced our bills though

[@American-In-Mykolaiv]

It could be that your house was insulated properly - especially around the eves where most external insulation issues arise.

[@MarcusT86]

How much did you pay?

[@davewozere2k9]

You probably manage your moisture properly. Using the extractor in the bathroom and the kitchen, opening windows when its stuffy. I once had neighbours complaining about mould in the back bedroom of a new build. Eventually I found out that they turned off the radiator in that room because they "weren't using it", would have a bath, not open any windows, turn off the extractor fan because it was noisy and leave all the upstairs doors open!

[@nhojnhoj6767]

Hello SNORKYMEDIA. How much did EWI cost? How many KWH on heating have you saved? John.

[@utube1818]

@@davewozere2k9 We had a similar scenario. Our new neighbours were a young couple with a baby, never opened any windows or doors had the washer on every day, did all there drying on clothes racks and radiators house full of mould.

[@tapeslayersreviewsreviews9807]

Cheers for this video Rodger. I'm going to send this video to a customer. To try and persuade her she shouldn't have it done.

[@WhiteManInAVan]

100% agree about the pros and cons of EWI. Since i got my house done, it never gets colder than 17 degrees in winter, meaning i hardly have to put on the heating. Just the moisture management, but ive got window vents in and PIV put in and make sure to open windows and use extractor during showers and cooking. I might DIY a MHV instead which will hopefully help. The other consideration is screwing things to the outside. If you have to take it down or move it, then its harder to fix as you have to foam fill, render prime and finish otherwise the holes or a bad fill job really stand out. Thank you

[@Bettys_Eldest]

In my rental properties I have fitted automatic humidistat extractor fans (I set them to about 60% humidity) in all the kitchens and bathrooms. I also fitted vented tumble dryers, and outdoor rotary clothes airers. There are adjustable vents in all the rooms and trickle vents on the double glazing, but I cannot be sure the tenants will use them. That said, since installing the extractors I have not had any problems with damp or mould.

[@hughdavis3135]

I find attaching a wood board as a mounting plate for lights etc works well. The board spreads the load - and my insulation is Rockwool slabs, as the house is very old, and needs to 'breathe'.

[@Criptonoids]

- moisture in the structure will not freeze until the dew point is reached - warm air can contain more moisture than cold air. 40% at +20C will have much more moisture than 80% at 0C not to mention -20C - that's why in winter, in a room with "normal humidity" there is more humidity than outside and the partial pressure of steam pushes everywhere it can penetrate - in nature, everything tries to get in balance - that's why in winter the constructions dry out in our climatic conditions - if drying is not blocked to the outside, for example with foam or vapor-impermeable plaster or paint - there is no place for dew to fall, then the moisture will dry without freezing! - I already mentioned a couple of disasters before, under normal conditions +20 60% in the room, a lot of moisture will accumulate in the aerated concrete wall during the winter, which will not be able to dry out quickly enough. - if you live at +20, 40% and there is no bathroom near the outer walls, then everything will be fine even if you insulate with a sufficiently thick layer of foam, the moisture that will condense in the winter will have time to dry out in the summer. -but if you apply foam of insufficient thickness, it can freeze through and then it will really freeze, but if there was cotton wool, then no problem even in this case.

[@chriswhellams8187]

Excellent Roger ! This is exactly the problem with UK housing stock. I moved to the Nordics some years ago and the difference in construction techniques is quite staggering. It is pretty much standard here to have wet floors in bathrooms with underfloor heating (which drives away sitting moisture) , walls, floors, roof are heavily insulated, triple glazing , double seals on outside doors and opening windows, moisture barrier (damp proof membrane) in walls and ceilings...which makes the entire house air tight and a potential nightmare for moisture and mould growth...except that all houses have forced air ventilation and there are building regs which require proper flow calculations etc We have a ventilation fan on the roof which runs 24x7x365 drawing fresh air and ventilation ducts running throughout the house. There are fresh air ducts in external walls allowing outside air to be pulled in under control, these can be closed when its very cold in winter. In more recent years the newer systems all use a heat exchanger to recover heat from the exit air flow - it is very rare to ever see damp , condensation or mildew problems and if you do find it then it indicates a serious problem....it also makes your house un-sellable ! The vast majority of people in the UK have "insulation" rammed down their throats but without any follow up regarding the need for proper air circulation . Its difficult in the UK because of the age of housing stock and also house design e.g. soil pipes are fixed to outside walls as you nicely point out. Keep up the good work and keep educating people , as you correctly state - insulation without managed air circulation will typically result in solving one issue and creating another.

[@utubeape]

so do their houses cost a fortune after all this?

[@tlangdon12]

@@utubeape They don't cost a fortune, but they do cost a little more. The difference in construction techniques are not so great nowadays. The UK Building Regulations are bringing us closer to the Nordic way of doing things. You save the extra cost in the first three to five years due to lower energy bills.

[@utubeape]

@@tlangdon12 Yes with higher energy costs I think that is going to be the right direction to go

[@utubeape]

@@tlangdon12 The problem is still the majority of older houses, 1930's semis, there are millions of them and if old people live in them they will not see a way to recover the cost of exterior insulation via lower fuel bills if they think they are not going to be there for more than 15 or 20 years.

[@ianstobie]

In a war scenario or any emergency that causes frequent power cuts these airtight homes would be in trouble. But I suppose people would have more to worry about than damp. All the same, this Nordic approach does seem a potentially fragile high-tech solution. It assumes a wider service grid that will keep working properly without interruption.

[@vivalaleta]

Dehumidifiers don't cost much and do so much good.

[@jimdavis5230]

My previous house in Bristol was built in 1958 and had air vents in every room. Condensation was never a problem. When I built an extension I installed an air brick vent just above skirting level. That prevented any condensation problems in the extension. Heating is important but so is ventilation.

[@stuwilliam4943]

I agree Jim I have a cast concrete house built in the 50’s no concrete cancer yet than god. But i know people who have blocked the vents in every room and wonder why the mould is so bad. But trouble is it’s so hard to heat, people are always saying how cold it’s is.

[@dannylad1600]

@@stuwilliam4943, concrete cancer, wasnt that common for buildings built in the 70s?

[@allanb52]

Nice report, we are in Portugal and during the winter we use dehumidifiers and they take out a gallon a day. We have ceramic tiled floors and single skinned walls. The house it great for 8 months, but wintertime moisture is a problem. Denitrification is cheaper than the heating saved.

[@brettbarager9101]

I live in Canada but your points remain just as relevant. I bought an older house and one of the previous owners did the external insulation. The points you bring up around awareness of such areas as electrical, plumbing and other such wall penetration is invaluable. So is moisture content. This past winter I had no issues with it because I made sure I had a dehumidifier going. But, I was able to identify areas of heat loss. It is early spring here so I am going to address those issues before it gets too hot! Good vid. Thanks.

[@hughdavis3135]

It's been common in Slovenia for over 10 years now. But as a general rule they use vapour permeable insulation, and a vapour permeable render/stucco. Esp important on old buildings which generally need a breathable wall.

[@jakehewitt7418]

​@Hugh Davis my house is a hills presweld permanent concrete and steel structure, which I'm pretty sure is why there are pipes at random points dotted around to ventilate. Any idea if that's the case?

[@Diffusion8]

Open a few windows once in a while and you'll have no problems at all. EWI, properly done, is a great addition to your home!

[@robert_kotula]

You're such a refreshing guy when it comes to renovations. I've seen too many cowboy builder, especially when I use to work on home appliances and saw under all the kitchen cabinets. You're all about the quality of your work, you show the good and bad of everything and above all, the videos are very intelligent and straight to the point. Keep it going and home the channel explodes even more!

[@pawelutube]

I had on my house for last 20 years in UK. No issues at all , well spent money for sure.

[@Saltcoats1969]

Great video thanks! Home ventilation is one of the most overlooked aspects of construction. You can buy cheap moisture traps in the high street pound shops and these are a great indicator of just how much airborne moisture there is in your home. See how long one takes to fill before and after you make changes to your insulation or ventilation systems.

[@darthvader5300]

Just buy 2 to 3 industrial grade atmospheric water generators that will drain all the moisture from your house and produce drinkable water at the same time. And it will solve your mold problems and airborne moisture at the same time. The problem is that they all require power.

[@daviddavidsonn3578]

@@darthvader5300 and these generators run on what? unicorn dust? 🤣🤣🤣🤣🤣🤣

[@nvelsen1975]

@@darthvader5300 Water's € 0,001 per liter. Why on earth would you use expensive machines that need a lot of electricity, to make water?

[@richardcoffey6844]

Basically we are applying an unbreathable liner on the outside. Terrix vapour permeable breathable renders are the easy solution and they far outlast any other render on the UK market.Terrix plaster and paints offer the same breathable advantages,allowing movement of moisture air and high alkilinity means absolutely no mould or algae growth and a healthier place to live in.

[@dennissweet3570]

Roger, please take into account the 'Saturated Vapour Pressure' that forces the wet air through any gaps. It does not just float around! great video by the way, keep up the good work!

[@bengoacher4455]

Even if one were to fully insulate 100% of their walls with external insulation, or internal insulation, or cavity wall insulation. The moisture levels inside the house will condense on the coldest parts, which will then be the triple glazed windows you had installed. This will then cause big moisture issues in the frames of the windows and corrosion in steel framed windows, or rot in timber framed windows. The most critical thing you can do is manage ventilation in your home. It''s painful because when we are at home, we want to be warm, and ventilating rooms is the opposite of keeping warm. But I find if I'm out at work all day, opening the windows a crack to allow a through breeze on a dry crisp day is enough. Yes your house will be cold when you get home, but then you can shut the windows and turn the heating on.

[@MrQbee87]

Hi. I live in Normandy now (so the climate is like yours), but I come from Poland. East of Poland and it sometimes gets below -25C . I was in a complete shock when I saw how people in Normandy build their houses, or renovate the old ones. Complete lack of basic knowledge on how insulation works and how humidity works. Then they complain about the mold.

[@daviddavidsonn3578]

welcome to France 🤣🤣🤣🤣🤣🤣🤣

[@paulschlote166]

PLEASE PLEASE PLEASE take note of the dehumidifier emphasis in this video. Running a dehumidifier will not only take the moisture away, but will help reduce your heating costs, as you won't be heating the invisible moisture clouds in your rooms. It's easy to run them with smart plugs when your out of the house, and then you won't have the noise of them to deal with while watching tv etc.

[@timhancock6626]

You could install a humidistat extractor. It only comes on when humidity levels are too high. Most condensation and mould problems ( not all I hasten to add) are down to poor ventilation (blocked vents) or people drying clothes indoors using radiators. Ten years working in social housing and you see just about every scenario. It's not always the tenants fault though, sometimes it's the situation they find themselves in. Laundry block at the end of the street anybody? That's how they used to do it. 😉

[@VeteranofthePsychicWars]

He made that point at 7:39

[@truxton1000]

It does not really solve the problems as you can't have dehumidifiers in every room, they also cost money, and cost money to run. But of course, a lot of problems with damp is down to bad practices by the people in the house. Most people have not enough knowledge about these things.

[@Hansen710]

a house that is insulated after the new standards in most country´s needs some kind of automatic air system (because they are very airtight, and if you dont you get bad air quality).. i am instaling a heat recovery and that is a in a old house, it reaches all the rooms.. and it is more expensive then insulating the outside and a much bigger work the heat recovery system i am instaling also have a heat pump, and when you have that in every room its also more worth the cost and i am also using a wood stove for heat so it can recover free heat.. my water heater also works with heat recovery both of the is made by genvex my wood burning oven also have air intake from the outside, or else it cant get anuff air and that could be dangerous and make the draft go the wrong way under some conditions or it can bring down the oxygen levels inside to far, and become unhealthy a flir camera is a great tool to look after cold spots

[@truxton1000]

@@Hansen710 Yes all that is true, but very few are taking such steps so it results in more problems then it solves.

[@Bialy_1]

@@Hansen710 New homes are not made airtight to the point that you have no fresh air in it=no oxygen and you can somehow suffocate. Isulation is often made from stuff that is unable to transfer the water from wall to the outside and that water will be gathering inside wall and because of the isulation it will be unable to dry in the summer->your wall can have more water inside with every winter and then the mold will gonna attack it. Also recovery system is not a replacement/substitute for anproper insulation of the walls... "i am also using a wood stove for heat so it can recover free heat.." that sentence have no sense, wood is not free and the recovery system is recovering heat from your home(the source of it have nothing to do with it). "my water heater also works with heat recovery" also sentence with zero logic, you can heat water with heat pump not with heat recovery system->its not perpetum mobile... "my wood burning oven also have air intake from the outside" that is done for safety and in most of the places is forced by the law and have nothing to do with oxygen levels, its about carbon monoxide that in some cases can be created and that intake outside is an extra layer of protection against it.

[@worldsstongeststrains983]

In Canada this is called EIFS (exterior insulated finishing system). Fasteners are prohibited, panels are applied over a waterproof primer with mortar using a notched trowel allowing for drainage of condensation. Panels MUST run above the soffit line. Having visited the UK recently, I noticed a lot of failed EIFS systems. 99% of the problems I saw were improper installation resulting in water traps. I even saw a few in Irvine Ayre that were applied directly over shot stone stucco from the 1950s. If you’re going to insulate Britain ..please do it properly.

[@douglaslindsaychapman5188]

The problem with installing over stucco. I thought more mass was good.

[@geometron3646]

@@douglaslindsaychapman5188I guess he means the water traps, stuppled stucco or pebbledash will have lots of pockets, if the edges are ever compromised they'd become water pockets. I'm just guessing.

[@evapendaki2530]

In your EWI insulation you have to put a "vapor screen" to stop this humidity And inside to absorb this humidity you might have to add an airconditionning system. The surface of the coil will absorb this humidity You need a proper calculation for this heatpump Of course the basic is first to have a good ventilation I have done a lot of insulation,inside, outside and the biggest problem was the cold bridge We learn a lot just reading the comments, thanks everybody !

[@khalidjawaid9407]

Please kindly explain what is the cold bridge

[@mmars4032]

Works for the USA also as my house on the Pacific coast and this information explains the need for moisture control in an older house. THANKS

[@philipchambers1700]

Well done Roger on explaining condensation problems. I worked for local councils for about 2 years and condensation was probably the biggest issue I came across. The problem then is that because people do not realise how much moisture we release in a day is a substantial amount it creates as you say black mould. But in my experience with local authorities it is never there fault and push the blame onto the tenants. Education is what we need and properly ventilated houses. Keep up the good work

[@kitemanmusic]

How many people dry their clothes indoors? That is a real NO NO!

[@peterjones1354]

When I did my bungalow recently, I moved fence posts out, and the back gate, and had a boiler guy extend the boiler vent to get the insulation and render behind them. Job done very happy, and re-do of EPC showed house up a whole category from D to C.

[@andrewcarr2431]

Great Video and explanation of potential issues in the future. The building code here in Canada is addressing these issues and was a big difference to our life in the UK. But in a country that is -30 in the Winter and +30 in the Summer you have a wide temperature range over the seasons. The new code is EWI on the outside and lots of ventilation on the inside. Thus the air is circulating and humidity is being extracted. The old building methods of "seal up every crack" and being helped by new building science.

[@bobharrison1801]

Thanks

[@SkillBuilder]

Thanks! Your support keeps us going.

[@paulmaxwell8851]

You hit the nail on the head: insulating and air-sealing older homes is very, very challenging. I've done it and never again, thanks! We built a new super-insulated home and never looked back.

[@nofurtherwest3474]

so don't insulate old houses at all? I have 100 year old house, but it has no insulation. Should I just sell it and let someone else deal with it? It also has some knob and tube wiring. So what I've heard is I'd have to remove that (or disable it at least) before adding insultation in the wall cavities.

[@davidblyth5495]

For someone who comes from hotter climes it's interesting to see the challenges the cooler areas experience The presenter offers sound, practical advice!

[@duncanicook]

Hi Roger, We have had 3 and 2 bedroom flats (looks like a large Semi from outside) done last year. We removed the down pipes, svp, lights, gate etc. We then fitted new SVP on 97mm spacers , two new boiler flues which interestingly they put rock wool around to approx 600mm all around it. We removed the original 9 x 6 wall vents. The building was then insulated and rendered with a silicone render (luckily we had deep soffits) which appears to be self cleaning in heavy rain. We have trickle vents on all windows anti back draught (non shutter type) extractors in both bathrooms, anti back draught extract to outside fans in both kitchens, new down pipes with rawl plug, screw and adhesive clips & new 32mm vertical external condensate pipe running down to a mini soakaway, 1st floor flat roof space was insulated with wool to current standards..... My word what a difference it has made both flats, much cooler in the summer and much warmer in the winter & ZERO condensation. Alot of work, cost us £9K plus the £10K grant (which is another long storey for another time) but I now run the heating via the Vaillant combi boilers at 58 degrees (well below dew point) without the tenants knowing a thing!!! If done properly and not the way you are suggesting it is worth it. Next step is to redecorate flats which will also involve over sizing rads to 35-40%

[@SkillBuilder]

Thanks Ducan. What did you do about the soil pipe where it connects to the drain?

[@duncanicook]

Used a pair of offsets which because of the gap between the bottom of the insulation and the ground slipped into the clay adapter a treat.

[@leejenkinson5521]

I am helping friends and family with this at the minute, and have advised them just about the exact same as what you have done! Although, a few are doing internal plastering later so they are using limestone plaster to aid breathing and on the outside, they are going for graphite expanded polystyrene as the EWI contractors said it was the only type of polystyrene which was breathable at the time, and allowed for better moisture dispersal.

[@tonyedwards6369]

Ten years ago I dry lined my victorian semi wth bubble foil on the interior of the wall then battons and double bubble foil then more battons foil backed plasterboard taken down from the upper floors round the joists to the ceiling below .So the outer wall can breath. Very pleased with the results no signs ot mould. A dehumidifier in the upstairs bathroom deals with unwanted interior moisture...some energy cost of course. This type of insulation is only really affordable DIY and a challenge. Next summer I intend to dig a trench to expose the basement level walls to be foam sprayed when dry enough something of a guess though so far no signs of any problem in the basement so should be o.k. My semi has one bed flat and five bedsits ,three bathrooms and tree kitchens energy costs about £170 pcm no cental heating old balanced flue multipoint water heaters, and five gas balanced flue wall heaters. The wall heaters some forty years old pass inspection annualy, as existing do not need to have gas failute cut of devices. Multipoints will be changed next year,cost of pilot light alone decisively significant. Central heating ,no way, any saving on energy would be consumed by installation cost and short life of the system. Helpful having an honest gas fitter advising. Simplest is best is an old saying still relevant in these days of 'change everything for a fast installation profit installation'.

[@frr5004]

Roger thanks for bringing up the topic, for making an effort, and for warning people - that thermal insulation is no laughing matter, if nothing else. And, I understand your explanation how the food chain works in the housing market (from rental to construction), and how that "chain of command" results in sub-prime insulation jobs being an everyday reality. In my country, most of the housing is owned, rather than rented, but the problems are similar. IMO, the thermo-insulation technology has enough pitfalls and enough principles that one needs to comprehend, before being able to breathe the craftsmen at their necks from behind, that most home-owners just never get a grasp of the finer details before the mold growth actually appears somewhere (or some other fault surfaces). I disagree with you about your conclusion/morale: that removing humidity from the air is the solution. IMO, this is just a makeshift stop-gap, and troublesome. For one thing, humans do need some level of relative humidity, say 60%+, to keep their lungs and bronchi in good health. In that sense, letting your laundry dry in-house during the frostiest winter nights is a good idea, if you have an asthmatic child. And, removal of humidity costs electric energy. This is not to say that condensation and the resulting mold growth is good for for your respiratory tract :-) I mean to argue that the problem needs to be addressed where it stems from: 1) the insulation not being thick enough or uniform enough. An insulation that's not thick enough doesn't drag the dew point out of the construction wall into the insulating layer. And, those cold bridges that you speak about. I'm afraid attention to detail is key. You do need to have those construction details properly insulated, in the first place. Yes it hurts, but it gets the problem solved. 2) in addition to insulation, you also need a vapour barrier on the inside surface of the walls (or between the construction wall and your thick insulation layer) i.e. prevent the gaseous moisture from diffusing outward through the insulation. There's a nice video on the topic here: kzbin.info/www/bejne/oZC0iapnd6iNaKM 3) windows replaced by a better sealed model (more airtight) - so that in winter, when the condensation on cold bridges is most painful, and people shut the windows to prevent heat loss, inadvertent ventilation no longer exists, and the dry air from outside has no chance of diluting the moist air in the home. 4) no controlled central ventilation in the building (heat exchanger recommended, to retain/recuperate heat *and* moisture). I.e., it's a combination of factors, and each of them is down to some sloppy practice / neglecting some part of the complex system / trying to save money in problematic ways / resorting to an ugly compromise :-) For the last 20 years I've been living in a four-story commie-era apartment block here in CZ, built in 1962. I still had a chance to experience the building with hardly any insulation. In the eighties, they added a 12cm layer of some gas-filled porous concrete, not sure what this material is called in English - the thermal resistivity is nowhere near EPS or rock wool, but the neighbors who remember that improvement say that it did help quite a bit, compared to the original 40cm solid brick walls. And, when I moved in in early noughties, the building still had the old creaking wooden windows. Double-glazed, but not very airtight. The first thing that we did to save on heating, after a couple years, was replace the windows with some relatively modern (not too expensive) plastic-frame variety. Double glazed and airtight, except for a designed-in always-open "micro-ventilation". There was some mold growth around the window frames before the replacement of the windows, but after that replacement, the mold just got wild. After the first winter, I glued slabs of XPS on the outside of my window openings, on the "ceiling" surface (effectively the concrete beam/panel above the window, working as a perfect cold bridge) which did help somewhat. Quite to my surprise, our "owners union" did not take long to reach a decision, that we should add outer XPS insulation. I was among the advocates - and I did not promise too much savings on heating, but I did stress the expected effect on mold growth. And, I was right. We added 14 cm of polystyrene (XPS). It was funny to observe, during the hot summer while the insulation (including a new roof) was constructed, how *immediate* the effect was. Especially the top-floor apartments would no longer overheat as badly as in the previous years. The semi-insulated heating pipeline in our basement now effectively keeps the corridors and stairwells always warm during the winter. And our heating radiators in the apartments (now with thermostatic valves) hardly ever fully open, even during the toughest freezing winter nights. And, molds are gone. We didn't need to kill them chemically - we just washed them off, let the wall dry, and painted over them. They're GONE, for good. When this insulation project was about to start, I was already estblished among the neighbors as a techie/tinkerer, so there were no objections when I naturally started to check on the construction team on site, every day, meticulously - things that I was able to learn that need to be done right and that the construction people sometimes cheat. Such as, the reinforcement nets need diagonal additions across window corners, above and below (4 corners each window). And some other tidbits like that. They did not dare to dilute the spacing of the plastic anchors or some such. I was definitely not the official "construction site inspector", but we hired one (it's a legal obligation here) and I did report to him anything I didn't like. The construction company gave me a written notice that I should not climb the scaffolding, as I am not a member of their team - so I gave them a written response that I thank them for their care and that I do so at my own risk. Before the project even started, I actually provided some input into our RFP - specific technical requirements. How deep underground the insulation should be extended (we requested 0.5m, we could as well go deeper). And, 10 years down the road, the insulation seems to hold. Someday soon we may want to wash some dust off the facade and apply fresh paint, but otherwise, it holds surprisingly well. There are some issues with the rain gutters, but not very serious and they're getting tackled. The one unhandled downside is, that our building does not have central ventilation - and there's no space to add one. A central ventilation with heat recuperation would be wonderful, and I believe is (almost) mandatory in new buildings. The way it is, we just keep venting in the old lossy way. After all, we all need to breathe. There's one particular thing to beware of: gas-powered stoves. We do have natural gas in our apartments. These consume a lot of oxygen, produce a corresponding amount of CO2 and under some conditions, can produce CO = the dreaded carbon monoxide. The original kitchens didn't even have a dedicated vent from the fume hoods above the stoves. I have added an outside vent to my own fume hood, but still I need to have a window open while cooking. We have an excellent "gas equipment inspection engineer" turn up every other year or so, and he always takes great care to warn us, that the way the gas stoves were designed into the kitchens in the old days, is nowadays considered dangerous - and that we should always keep a window open while cooking, even if we don't use coalgas anymore (replaced by natural gas decades ago). That's about it... I am not a construction engineer. I'm a computer nerd. I was fortunate to find and purchase two interesting books on the topic, before our insulation project started. And, I was able to find free software to simulate the temperature gradients in some "construction details" relevant to our building. If you're interested, there's a short webpage, written by me, as an intro to the software... frantisek.rysanek.sweb.cz/agros2d/agros2d.html in my slavic mother tongue... maybe skim the pictures, feel free to enlarge, and Google Translator appears to do a surprisingly good job on my text on that page. P.S.: insulation is properly done on the *outside* of a building. If someone seriously suggests to add polystyrene or wool on the inside - humiliate them for their ignorance, have no mercy. There's a neighboring topic: insulation of tiled roofs having a wooden frame. Many people here still put insulation betwen the beams, so that they don't have to remove the tiles and do the right thing (which is more intensive in terms of labour and materials). Which typically results in water condensation in the insulation and rotten wooden beams. Because the vapour barrier is almost impossible to get right. If a tiled roof is desired, long-term the relatively least troublesome way is to insulate above the wooden frame (again: on the outside of the building). Thus, the frame enjoys a relatively constant non-condensing humidity and a stable temperature. Only the overlapping ends of the beams need to pass through the insulation (if not solved in a different way).

[@douglasasselstine7497]

Thank you for the heads up...from Canada.

[@stevesmith3395]

So pleased you mentioned this. I had this issue when moving into my current home. Dehumidifiers are useless. The internal wall insulation caused this. It's also caused damp under floorboards which has also led to an internal wall having damp. I sleeved vents and added new vents to solve the sub floor issue to some extent but a neighbour has had all his floorboards rotted away because of this insulation. I solved the humidity and constant mould growth via a positive input ventilation device in the loft. This pulls in less moist air from outside and pushes the moist air out as a result. Really cheap to run but make sure you get the one with a heating element to temper the air. Beware with insulation because the humidity and mould caused me to develop asthma after being in good health before moving in. It's very hazardous to health. Just constantly cleaning the mould is not enough.

[@SkillBuilder]

That is all good information, thanks for the comment

[@daveking777]

@@SkillBuilder roger could you do a video on why a bath plug hole gurgles when you flush the toilet ? What is going on ?

[@DMC888]

The PIV unit must be a lot cheaper to run than a dehumidifier.

[@stevesmith3395]

@@DMC888 it is. Also a dehumidifier is effective in a small room but you need to usually keep emptying the water collection container. Don't get me wrong, I used one in my little extension that was too cold before I ripped everything out and insulated. It did a job but it's a sticking plaster rather than fixing an issue. So.rhe PIV fixed the unhealthy situation upstairs and the new internal.insulation has fixed my cold extension which saves me losing so much heat downstairs.

[@dovedaledampcureserviceslt2248]

Good comment. We are leaders in PIV installations in the north of England and routinely find ourselves working on such properties. EWI literally means one MUST consider the merits of PIV.

[@davefoc]

American here. Very well spoken guy. Interesting topic. He did take a bit of time to get to the point though. I have been to Ireland and it was a wonderful trip. But I noticed a few things. Unreinforced masonry walls being used in new construction. As a California boy that struck me as very strange, but I guess where earthquakes are uncommon resistance to earthquakes is less important. Another thing I noticed about Ireland was that it is really wet. I imagine that sorting out humidity problems in houses is a big issue. It was interesting to hear some of the things that are done to combat it. Possible topic for this show. British house construction versus American. I watch Grand Designs and some of the British construction techniques strike me as being unnecessarily labor intensive or expensive. A few things 1. Masonry walls for internal construction. Why? Hard to run services, hard to make future changes, labor intensive 2. Retaining walls made out of blocks. Why? Seems less strong than reinforced concrete, more labor intensive, more permeable. 3. Blocks being used to make posts for post and beam construction. Why? Seems like a sonotube form filled with some rebar and concrete would be cheaper and use much less labor. 4. American "cinder blocks" usually have holes for rebar and concrete for reinforcement. Even in high load areas like on a high retaining wall the Brits seem to use solid "breeze blocks". Why? A very strong retaining wall can be made with less labor, less material and less time using cinder blocks with holes for reinforcement. The Brits also seemed to have taken much longer to adapt to power saws and nail guns than the Americans. Based on Grand Designs it does seem that the Brits have now discovered nail guns and power saws. But based on Grand Design episodes the transition happened many years after the transition in the US.

[@piyush3549]

Great video roger as usual. My thinking would be, Control layers of any building have to deal with Water, Air, Vapour and Thermal in that order only. Air tight envelope comes before insulation. Insulation is cheap and insulating is easy as compare to doing an air tightness and making sure it passes the air tightness test. If cold air moves around the building meeting warm air is going to be the biggest issue. Also if cold air moves around, it will reduce the effect of insulation that supposed to hold warm air. Unless we understand the building science, I am afraid we will actually end up ruining our existing housing stock.

[@rudgemeister]

Really good. Go easy on the insulation protesters, they are making a general point which I get the impression you agree with, as do many of your comment writers. No one is an idiot, just different perspectives. You are doing a great job on the practicalities.

[@SkillBuilder]

They are idiots because they have alienated people and harmed the cause. I have met quite a number now and they don't have a clue about any of it.

[@How2Extreme]

hi Roger thanks for covering this subject up.May be more of my clients are going to accept replacing and extending all the pipes because most of them don't accept the extra cost and it can have a big impact on the system.Thanks i always follow your advice

[@alexhaerens6116]

It’s not the insulation that is the culprit, its the way you do it. One : moisture in the air will always condense on the coldest surface. Two : dry air causes no condensation. So the message is to keep moisture out to the max and eliminate cold bridges. To this goal we put massive isulation on the outside of our overhanging roof. Yes, for this you have to remove the rooftiles and refit them on top of the insulation. Next we put the wall insulation all the way up to connect with the roof panels. No cold bridge there. Since the gutters were deteriorated we had to redo them, an excellent opportunity to also move this outwards. On earth level I dug a trench, 60 cm deep, around the foundation of the house. In here came glued panels of foamglass. This is more or less eternal insulation. It doesn’t soak up water, rodents don’t eat it and it’s firm enough to take loads. Making the house isulated all around, 60 cm deep. The walls were covered with a synthetic plaster. Also have to mention the windows. Half rotten single glazing units. So they als got thrown out and were replaced with PVC-units, brought in line with the insulation layer. End result : a dry and warm house. The floor, even while it’s plain earth underneath, feels comfortable, even in the unheated parts of the house. We actually live on a thermal island. At 22:00 the heating goes down to 16 degrees C, even in the coldest winterdays you find the house still at 19 degrees minimum. The renovation of our 9 x 9 meter house, 2 floors plus attick, cost about 50000 euro, 13 years ago, equally split between walls, roof and windows.

[@SkillBuilder]

That is what the video says

[@ro63rto]

An old neighbour did this to their entire house. The current owner tried to claim we had moved the fence line when we replaced it saying her alleyway was a lot narrower than ours. She felt stupid when I pointed out how much deeper her window openings were and at the bottom of the wall you could see the overhang.

[@SkillBuilder]

That is very amusing

[@tonybarrett8543]

When she bought the house what did she think the surveyor and solicitors firm where for?

[@MENQN]

Also it will take away the personality of the house if its pre 1920s classic solid wall brick layout by the covering with the insulating boards

[@SkillBuilder]

It is perfectly possible to put brick slips onto the insulation. If you Google EWI before and after you can see a lot of different finishes.

[@CB27]

Had EWI installed 8 years ago. 1930's built solid brick house. They did it properly. They even put a bend in the soil pipe. There are no "blank" spots. It's been nothing but positive. We used to get mould in the corners before in most rooms where condensation would meet cold walls. Despite having humidistat extractors and running two dehumidifiers. The day the insulation went on (Feb), I had to turn the central heating thermostat down by 2 degrees as it was getting too warm inside. We have no more mould growing in any corners. The only fly in the ointment was the patio doors no longer swing all the way open like they used to as the insulation stops them opening beyond about 95°. But I have a cunning plan to remedy this when I come to replace the doors.

[@TheBooban]

Well you should name that company then. Otherwise spending extra money and electricity on a dehumidifier doesn’t make sense to me. Don’t do insulation on the outside. Just on the inside.

[@JT-si6bl]

Brilliant vid! After EWI a house with a Pava-Tec solution and finished with a zinc cladding, soon after, the customer found windows reveals soffit zinc work weeping significant moisture, all because of the efficiency was so high. The heating was rarely on after too.... The house was 200 years old and without any insulation before. So, the 'exhalation' or drying out period from extended dew points was significant because of the previous years of moisture accumulation (dew points) beginning to shift. That's progress. Dehumidifiers are the way for a couple of years! Stone/brick can also leech moisture to the interior space due to the exterior skin being 'tanked' by non porous insulation. The amount of terrible fitted insulation I have seen is abysmal. The gaps accumulate the percentage loss of heat significantly. The insulation is only as good as the installation.

[@jodiecreaser5553]

Great video. I work for an MVHR distribution company and this is a key area that often gets missed when looking to better insulate the home!

[@inderveerjohal7218]

who do you work for? I'll be needing MVHR for my renovation project. And do you sell any systems with cooling added? I know it wouldn't cool much but combining that with an ASHP that does cooling and UFH/UFC throughout, with measures to control thermal gain, I was thinking it might be enough to keep the house comfortable in really hot weather... we are in south-east of England.

[@erdscloud-buildingassetdat8178]

Hi Rodger, I'm in the process of self building a new house. You have given me a lot to think about. Thanks.

[@geoffaries]

Another great video from Roger. I have worked as a consultant for housing associations and to their credit their new builds had high levels of insulation and air tightness, complete with MVHR systems, sadly no one explained to the tenants that the filters had to be cleaned regularly or that the 2 fans had to run 24/7/365, when they found this out then most were switched off. The units weren't serviced as the maintenance contractor didn't get a budget for it.

[@1414141x]

Seems to be a nationwide problem. Councils spend a fortune on the old council housing stock and then just leave it to rot. Don't know if housing associatons are any better. It's a bit like buying a new car and never servicing it. Prevention is better (and cheaper) than cure. But they just have not got the budgets for it.

[@jodiecreaser5553]

So true. I work for a mechanical ventilation distribution company and we've had to replace many MVHR units because the tenants weren't made aware that the units needed servicing and at the very minimum, having the filters changed or at least cleaned!

[@alan2804]

Id turn the MVHR fan off if it ran 24/7/365 too! An automatic version would cut the running costs and changing filters is simple. I wonder listening to all that’s going on in the building industry, councils and govt if anyone has got a joined up plan for energy efficient healthy housing stock to replace the majority of old damp leaky stuff, I know the answer.

[@johnhaller5851]

​@@alan2804If the house is well sealed, the ventilation also helps remove CO2 that we humans make, in addition to removing humidity. Drafty houses didn't have issues with CO2, as there was a good air flow in and out of the house.

[@peteroreilly3324]

I dont need to get this done i just randomly came across the video and i must say what a fantastic explanation. Very easy to follow

[@ZicoTheMysticalWarrior]

We had EWI done last year, it reduced our bills and its made the house much more comfortable our solution for moisture is easy those window things open you know 😛 Actually the company who did ours almost insisted we had trickle vents put in but I did explain we would be installing MHRV eventually and in the mean time I'd just put the window on lock. I'd say the biggest drawback is the fragility of the EPS it's probably not suitable for houses that are directly onto a main road with high footfall its quite easy to damage the render with a hard enough knock with a bike or scooter for example. Not the end of the world but it needs fixing promptly when it happens.

[@laidbackLUKEY]

I agree, seems very susceptible to dents with such a thin layer of silicone render over the top

[@ZicoTheMysticalWarrior]

@@laidbackLUKEY I don't think it would matter how thick/strong the render was the underlying EPS is the weak point. I wonder if PIR might be a little more resistant to damage.

[@teripurewal1970]

@@ZicoTheMysticalWarrior please could you tell me what PIR stands for? Thanks.

[@ZicoTheMysticalWarrior]

@@teripurewal1970 polyisocyanurate I believe

[@giogio4833]

There's a house near me and the kids have played football against the wall.theres nothing left of it now 🤣

[@williammaguire1130]

In Ireland we install external wall insulation and extend all the services like soil pipes, gates, meter boxes etc . Also, soffit can be removed where one exists and overhangs are adequate to eliminate cold bridging in this area so we're able to achieve very nearly 100% cover with ewi.

[@Tom-Lahaye]

I'm going to have EWI fitted to my walls and I realised that it wouldn't be an easy job. Doing research for myself and identifying all the problem spots it turned out that it can only be done properly in conjunction with a total house renovation. So that's stipulated out my plans. Got new window frames with tripple glazing fitted, I insulated the cavities 50cm around all windows to minimise cold bridging around the frames and especially trough the outside window sills which are in blue stone which protrudes into the insulation (these are mounted on brackets to keep them isolated from the outer leaf of the brickwork). The flat roof is going to be renewed for a warm roof in a couple of weeks time, the edges have to be built out to accommodate the extra thickness on the walls, the saddle roof will have its eaves widened, luckily does the gutter tray on the front and overhang at the rear allow for the insulation. Floors on the level which are wood are replaced with insulated concrete floors on a sand bed because under floor ventilation gets nearly impossible from the outside without breaking the envelope (floor joists are bad anyway). Insulation is taken down to 40cm below floor level or ground level outside, so it means digging around the house. At the garage which doesn't get EWI the outer leaf has to be cut out where it connects to the house to continue the insulation into the wall cavity, the garage walls will get cavity insulation, and the inner wall between the garage and house is also insulated from the garage side. At places where pipe or ducts go trough a wall the hole is widened and insulation fitted around the pipe or duct, I try to minimise the amount (luckily we don't fit soil pipes on the outside in the Netherlands) And finally ventilation with heat recovery will be installed. As you can see there is a massive amount of work needed and things to consider before EWI can be installed, and when EWI is installed you have to discus every outside fitting which has to go on the wall afterwards, even for a light or birdhouse, as reinforcement pieces have to be inserted where screws or nails will go in. Fitting things otherwise will damage the rendering and make guarantee void. I discussed a lot with the company which is going to fit my EWI, and if I forgot something I wrote it down and asked them again, and also show them all steps I do in preparation in detail and ask their opinion. That's the only way I'm sure you get a satisfying product at the end, and it doesn't come cheap for sure.

[@michaelmayo3127]

"frames with tripple glazing fitted," Triple glazing will give only microscopic savings on energy. It's also become aware that triple glazing could be the cause of health issues.

[@Tom-Lahaye]

@@michaelmayo3127 It's true that tripple glazing compared to modern double glazing gives you just an around 15% higher insulation value. But it does a much better job in keeping noise outside, not unimportant if you live near a busy road. Because the government gives a high subsidy on tripple glass in the Netherlands the eventual cost is not higher than for double glazing. The health issues you talk about are not caused by the glazing itself, it's due to poor ventilation and will also occur with double glazing in an otherwise well insulated house. This because in a well insulated house everything is made airtight as possible to prevent heat loss via drafts. But this also limits natural ventilation. A form of mechanical ventilation is needed, and to minimise heat loss via these there are now heat recovering ventilation systems which extract the stale air from the inside of the house and transfer the heat in this air to new fresh air blown in via a heat exchanger. The ventilation unit also has a particle filter, so the air which is coming into the house is even cleaner than the air on the outside, given the filters are cleaned or changed as specified.

[@michaelmayo3127]

@@Tom-Lahaye "The health issues you talk about are not caused by the glazing itself, it's due to poor ventilation" The health issue that I mention have nothing to do with ventilation. Ventilation:- be there 2 of 3 layers of glass they will not effect ventilation. "15% higher insulation value" is an outstandingly high value for glass. Are you sure that you have got that one right? Are you confusing noise leaves with heat efficiency?

[@Tom-Lahaye]

@@michaelmayo3127 The 15% higher insulation value for triple glazing is when compared with double glazing. The insulating effect of double and triple glazing is not from the thickness of the glass panes themselves, but from the cavities between each pane of glass, typically between 12 and 16mm. These cavities are filled with argon gas, an inert gas which has a low heat conducting value compared to air, which you will find in older double glazing. The gas is sealed in and does not move, so has a very low heat transfer. These types of glazing are known as HR, HR+, HR++ and HR+++. Typical U value for single glazing is 5,7, for old double glazing 3, HR 2,0 HR+ 1,6 HR++ 1,2 and HR+++ (triple glazing)0,9. These values denote the Watts per square meter of glass for each degree Celsius of temperature difference between the in and outside of the window, so the lower the figure, the lower the heat transfer trough the window. The value of 0,9 is as high as for 30mm thick XPS insulation, and as you can see the 15% difference between tripple glazing and the best double glazing is very conservative, these figures which I looked up on building code sites of the Netherlands show around 25% difference. Lastly you must explain me exactly why tripple glazing effects your health and double glazing not when they are made of exactly the same materials (glass and argon gas which are both totally inert to the body) if poor ventilation isn't. Is this one of these conspiracy theories? As far as I know poor ventilation and related condensation and mold is what affects your health in a negative way.

[@michaelmayo3127]

@@Tom-Lahaye I lost what I had written to you but, I will recap with out the technical details. Optimal distanced between the two layers of glass 16 m/m. Aluminium shouldn't be used as edge material in double glazing because is causes cold-bridges. One of the layers of glass should be treatment with a transparent metal that allows heat from the sun to enter the building but reflects any heat from the building, back into the building. This type of double glazing has the highest efficiency to date and its measure to 5%. Adding an extra layer of glass won't change this efficiency rating notably and it will certainly not increase the efficient by 15%. But, may be 5/100*15 = 0.75% or less that 1%. As regard the health issue with 3 layer glass. This was from a article that I read in the Danish publication - The Engineer - which is a publication of note. The article's main subject was about thee-layer glass base on a study by the DTU Danish Technical University: - also an institution of note - Of the effectiveness of thee-layer glass that had been installed in two hight-rise (400) dwelling in Copenhagen. the conclusion was that thee layer glass did't improve heat retention efficiency, as oppose to two layers.The health problem was mentioned because residents complained . DTU conclude that a study should be made with regard to these complains.

[@dbat3291]

Looked External Insulation being done pre pandemic. Thanks to this video, I went on the EWI Store (EWI Pro ) course. Similar to the Webber one by the sounds of it, didnt get a response from the latter; one day, am lecture and then pm hands on and recommended. Now to save the pennies for materials. Got air bricks in most rooms so getting there but plan to monitor moister until I'm ready. Keep up the good work Roger.

[@tonyk132]

I've always been amazed by how far EWI has been adopted in the UK without any mention of WUFI calculations and condensation risk. Great comments below highlighting that the condensation issues are often transferred to other non-insulated areas. Maybe Roger can highlight how a building can be insulated either internally or externally whilst ensuring the wall build-up remains breathable for old solid brick properties. I've attended a webinar about a clear external liquid applied breather membrane for masonry. If anyone has any experience of this system in combination with internal wall thermal lining I'd be interested to hear them.

[@Darrida]

WUFI is a linear model of heat and moisture transfer. In real ingineering it is better to use some FEA for isotherms in building's details. You can make house airtight by using XPS or XPS/MineralWool in EWI.

[@Bialy_1]

If you gonna put the insulation inside your external wall then the wall will be not protected from the external cold but it willl be separated from heat-> you can easly end up with your external wall freazing in winter and if there is any water inside there can be a huge problem because ice have more volume than water->that is how most of the sand on this planet was created, from huge solid rocks were crushed by freezing water in them->and you do not want to change your external wall into smaller pieces... Generaly in the topic of breathing the water is accumulated in the winter and if its able to "breath" then it leaving it in the summer. You can calculate all of that but for that you need exact info about avg temperature in your locstion and how the wall is constructed and what kind of materials were used. "that the condensation issues are often transferred to other non-insulated areas." it is not a transfer, the problem is in concentration of the condensation in a much smaller area because that will be the only cold place and other parts will be to warm for the condensation to start=that water will be left in air and all of it will be able to condensate only in some small areas(heat briges) and too much water in one place=mold gonna start to growing.

[@hughdavis3135]

We used Rockwool and a vapour permeable render. Zero issues with moisture build up, and the EWI was done a good 10 years ago. Pretty nuts to use an impermeable insulation for EWI, esp on old buildings that need to 'breathe'.

[@janmo519]

Our House is from 1887 and i build a 120mm thick Resol (Formaldehyd based) insulation on the Walls. Three thinks i use so we have No Problems with condenswater: Clay, Lime and Windows that are less insulaitet than the Wall. In Bathroom and kitchen we have Lime and Lime Paint on the Walls, in all other rooms there ist Clay on the Walls. The Materials absorb the Water in the Air and regulat it. The Rest condens on the Windows e.g. whenn you Take a shower or Cook. No aktive Parts, No Filters and a great Feeling (and cheaper than Concrete and Gips) Greatings from Germany

[@dukebbb6539]

Great video!!! I was hoping for another explanation for cavity walls where it's prominent in my area. I am in the HVAC trade and very aware of proper ventilation. I can sense stale/contaminated air the moment the front door opens. Also all the scented fresheners, I like to call them "odour masker", makes me wonder why there are so many people with cancer nowadays. I find the people willing to spend all the improvement money trying to contain all the heat in the house aren't willing to operate a dehumidifier. I've encountered many idled HRVs/ERVs due to "energy consumption". The same people aren't utilizing a hood fan while cooking....why exhaust "precious" energy to the outdoors? keep all the heat inside the house!

[@lexpox329]

wow that's very revealing about the lack of information the people in the 'insulate!!!' community give out. Only talking about heat energy and not the whole picture. Do you find people understand when you explain the problem to them?

[@tlangdon12]

So often the problem is education. And the problem starts early, when fathers don't educte their children, especially girls, on how houses "work". People would never turn their freezer off to save money, so why do they think they can turn their MHRV/PIV off to do so?

[@josepeixoto3384]

them odour maskers are killers; studies show they can be worse than smoking, only a fool would use them; i am allergic to some of those chemicals, i get a metallic taste in my mouth and throat,and breathing becomes difficult; just one whiff,before i run off, and it takes me a couple of hours to recover; also,they are totally forbidden in hospitals.

[@flynnjp19]

Excellent video with clear explanation and illustration.

[@DominicClaxton]

So in order to save approximately £185 a year in heating costs (according to gov stats), the solution is to insulate the house and then provide some way of de-humidifying the rooms which will cost approximately £150-£250 pounds a year to run, not to mention the cost of buying installing and maintaining the units themselves. So what's the benefit? Further to this, certain areas including Greenwich in London are pushing through legislation forcing landlords to improve the efficiency of the houses they rent out. This might sound like a great thing and and it is... until you realise its not as great as you might think. In order to be able to rent to someone beyond 2025 the house must have a EPC rating of a C or higher. If a house has a rating of D, E or F then landlords must bring its efficiency up by insulating the walls. So now the tenants will be saving £185 a year, but cost them £150-£200 to keep the humidity down and prevent damp and black mould! And the knock on affects? If landlords don't carry out the works (because it will cost landlords around £15k to do so), they will not be allowed to rent their properties out, which will force a large number of private sector properties to be sold which will mean less houses to rent. This affects roughly 1 in 4 private rental properties in the UK. And if landlords do carry out the works, rents will rise as landlords try to recoup their losses! So the winners are.. the local government.. the loonies in the street.. and the tradies carrying out the work… oh and the company who makes these products? !

[@adrianrudd3943]

Well done mate, No nonsense, just the facts; Hard to find these days.

[@stuffoflardohfortheloveof]

Really well put Rog. I get a Little frustrated with people knocking the external insulation system and I’ve got no axe to grind either way actually. It’s a little like I remember when double glazed windows first came in, quickly followed a few years later by adding trickle vents. I recall many arguments querying the fact that you’re losing all the saved heat 🙄😀. It’s a good, genuine point and one that does benefit from a heat recovery system. 👍

[@leejenkinson5521]

I raised this with surveyors who went out to assess a friends property for EWI, since now to get the Government Grant for EWI in the UK trickle vents are a primary condition of grant approval! And when I suggested why not just open a window onto the security latch/night latch would just be as effective. Either way grant fund is not approved currently in the UK (though funding ends in September 2023) unless the homeowner agrees to extractor fans in the kitchen and bathroom, along with trickle vents and internal doors modified to allow greater air flow! For current funding to be approved you have to have 2 site surveys, the 2nd of which is to asses for air and moisture analysis!

[@francoisbouvier7861]

Well done, from western Canada. Air management!

[@chrisdunworth8720]

I've observed about 6 houses here in Ireland getting EWI. None of them had the soffits ( they were usually about 200mm deep) removed to take the insulation up to the wall plate to meet the attic insulation. Result a big cold bridge in just the worst spot in a room where the ceiling meets the external wall. All there were done by "professional" outfits. Actually in case the soffits were replaced but the insulation was not carried all the way up the wall As Roger says it's all in the detail

[@kyledavidson7475]

I've installed ewi on houses all over Scotland and never removed sofits. Always told just take it upto the sofit and if the roof overhang isn't big enough put the Angled top cap on.

[@July-A7]

I did EWI on my house. DIY. Best decision ever. I didn't take the soffits off but pushed loft insulation down in the space, while still leaving a gap for ventilation of the loft. No cold bridging, no mould whatsoever.

[@anneallen7890]

Hi Roger. I love it when you go off on a good rant about stuff

[@questioner1596]

I realize this would involve interior changes, but my understanding is that a wall needs a vapour barrier in the first third of the heated side. That way, the moisture is stopped before it can go deep into the cold wall and condense.

[@markbellingham4536]

I said it before great teaching instructor top man. 👍👍👍from a 67 year bricky

[@SkillBuilder]

Wow, thanks

[@CsöszakiHoszivattyu]

I am from Hungary , we insulate house outside nearly 30 years, but our house is solid house no cavity, breeze block wood frame etc.. If done properly the insulation no issue but need a good tradesman who knows how to do it..

[@TheFool2cool]

Sort of missed the point of the video, you need to understand the movement of moisture

[@StreetBobberVlogger]

We do EWI and have to say we always extend the roof and replace all gutter and fasure, remove all soil stacks and re do the drainage. All aspects are attended. We also dig down the footing to reduce the cold bridging between the uninsulated slab. Conservatory’s are the only real problem. Garden fence posts are really not a big deal to remove. It’s a brilliant product if done right. Our company does build low energy passive homes as well, so many skills under our belts. We don’t just whack a bit on the walls and hope for the best.😂

[@pdtech4524]

My mum had the outside wall insulation blocks put on her bungalow a few years ago now and it made a huge difference making her home warmer and cosy. She said it was like a tea cosy had been put over her little home and sometimes she was too warm so had to open windiws etc Which I guess helped to.keep air circulating because she didn't suffer any signs of increased damp or mold etc One other thing she had fitted at the time was sonekind of solar chimney thing which maybe helped the movement of air and vent any moisture?

[@1414141x]

Yes, probably there is no problem with one or two people living in a bungalow or a small house. The problems of moisture build up mostly comes when there is a large family - say five people or more. Each individual giving of moisture, plus all the bathing, the clothes washing and drying etc. Same issue in HMO's (houses of multiple occupation). You have got to have some means of extracting the moisture from the air - The old method was gaps in the houses ! So air was constantly being replaced. Now we live in haemetically sealed boxes so the air in the house is pretty much static and is not replaced. So you need a moisture extraction system. As Roger explained the moisture will build up and condense in the 'cold spots' on the walls, or where there is little air movement because of furniture against the wall. If you seal the house up and moisture builds up it can actually dampen clothes and furniture, resulting in mold attack.

[@pdtech4524]

@@1414141x I've lived in damp and mouldy property before, some houses are just more prone to it than others. The thing is some people don't realise you have to open windows, ventilate the house and don't dry all your clothes on radiators etc People have hot baths, showers etc don't open windows and wonder why the walls are dripping with moisture and condensation and mould starts to grow ... Dryers are another issue, especially vented ones where people just run them into a bucket or sink, steam everywhere etc Also not having your heating on enough can help moisture build up.

[@HunterofInvisibleGame]

Greetings from New Zealand - Great Video - we are currently improving insulation to our building code

[@salibaba]

We had EWI installed over a year ago and what a difference. There's more emphasis on fearmongering here. All our drain pipes were replaced as part of the install (even extended our garden water tap out), flue was extended fence detached and reattached. A building warrant was required but we didn't need to worry about that as the installers did everything. All the local housing assocations used the same company as we did to similar houses round here and they've done the same for all those, looks great.

[@rob5944]

How much was it?

[@salibaba]

@@rob5944 I'd love t be able to tell you but I don't have the details to hand. I can tell you that it maxed out the grant which paid for it (greenhomes grant i think) and had to pay the remaining £300 ourselves.

[@rob5944]

@@salibaba that's pretty good. I was hoping to get a handle on the costs because I'm guessing that the government won't be to fund every household in the country. There was a feature on the news where a couple spent £36 1/2 k on cladding their 30s home.

[@salibaba]

@@rob5944If memory serves it had been between £10-12K, ive googled what the limits of the scheme were and lists 10k max, so that sounds about right. Had a similar figure on our old EPC. It seems to have cut our heating demand by about 1/3.

[@rob5944]

@@salibaba then I suppose that example I mentioned was for some similar sort of system, although it was a sizeable house. I cannot help but wonder how the average homeowner can afford to finance a project like this, and whether all houses will be suitable. One thing is for certain, it's a huge undertaking. What seems eminently more achievable is the production of true green electricity, I can then run my heaters with impunity. 🤔

[@c0rnd0g_19]

Remodeling a 40-yr old place in the U.S. I am NOT air sealing the house because of this reason. It's lasted 40 years with its breathability (we have SUPER humid summers and cold winters, a vapor barrier on either side WILL cause issues half the year) and I know enough that taking that breathability away will cause problems. I am putting all new insulation in every wall and in the ceiling, the difference (we're 75% done) has already been amazing. I know it will never compete with a modern house, but I also know it's much better insulated than any other 40-yr old place and it isn't going to rot around us because of condensation.

[@george9710]

This is a great educational video and I really hope the message landed! Many home owners completely neglect that a new build is better insulated but it also has airflow management which is now mandatory. If you want similar performance from 100 year old house you must use similar principles and air flow is essential to EWI. I just wish large installers were more upfront about the need of it and provided a complete solution but we'll get there

[@darkknight17]

Hi mate, I am about to get my 1950s done with EWI, any tips for air management would be appreciated. I have trust issues with builders and like to do my own research and chat to those who have experience. Thank you

[@supergrafxengine4620]

Very true video. The moisture needs to flow out. This is why you still need a air fans to gently push the air out or a dehumidifier to collect the humidity.

[@julianthornton9076]

Well said Rog, the problem with all the new technologies is that they are often conflicting with older ones in existing properties, reading the comments some find they have no problems where others have a nightmare, we worked on a property where a rising main had been leaking into an external stone wall for years, the whole house was black with mold & they had tried everything regarding the insulation fix, even after we fixed it, it was 6 months before the problem went away, possibly with the price of fuel the condensation problem will revert to the outside of the walls because we cant afford any heat!

[@fabolvaskarika7940]

The “problem” with new technologies that some try to profiteering on the trend, without having the skills to do it. There is nothing to do with the technique, but everything with human greediness.