Dealing With Dampness in Walls 100% Fix

[@stuffoflardohfortheloveof]

Worked as a grant officer in the welsh valleys many years ago. We had/have quite a few 2-storey front/3-storey rear terrace houses with steel grills on the front pavement that, historically, could have been the coal merchant drop off point to the underground basement. These, over the years, were bricked up and had windows fitted allowing light into the basement. The damp issues were enormous but building control came up with a relatively simple, and the cheapest, solution in that they allowed the ‘builders’ to construct a complete inner block wall forming a cavity as they went. In the bottom of the cavity was an open channelled gulley that, as you said, allowed the collection of water and delivered it via a new drain out to the rear of the property. Always seemed to work a treat. 👍

[@derryjones1029]

Roger knows his stuff fairplay

[@hs6404]

This man is a great instructor and communicator!

[@gdfggggg]

I’ve used SBR mixed with cement very successfully in the past.

[@SkillBuilder]

I love it a bit of SBR

[@malcolmfunnell4501]

Very good product , but once it’s on any movement of the structure will breach it , for me it will be used above ground only

[@gdfggggg]

@@SkillBuilder it's like PVA on steroids.

[@mindaugasvaskevicius1818]

I believe that the damp should be minimized from entering the concrete, because at a certain point of damp it erodes/weakens the concrete. By sealing the damp inside the wall it solves the problem inside and on the surface of the wall, but the sealed damp can damage the structural integrity of the wall. I need to do the outside thing, mentioned in the video, alongside with thermal insulation, then I'll decide if i need to damp proof my basement from the inside. Another thing that worked for me: sufficient ventilation

[@bertharius9518]

I had a utility room where the external ground level was at the height of the ceiling. (The old house was built into the side of a hill). There had been damp issues for some time - even pools of water on the floor. I removed the old plasterboard only to find that the original wall had foil-covered insulation all over it and was saturated and moldy. I removed all of this to then reveal that the wall looked as if a bucket of water had been thrown at it. Anyway, built a timber framework - horizontal battens (with dpm strips behind them) and vertical battens on top. Fitted new damp-proof plasterboard and several vents were installed at the top and bottom of the plasterboard which were then mostly hidden by new kitchen cabinets. Since then, no smell, no damp, no problems. Of course, the original wall may still be slightly damp but within that framework cavity, it is constantly evaporating through good ventilation. I'm sure some professionals could offer an alternative method but I just thought that if you SEAL IN the damp it can only get worse. (This is not to suggest that Roger is wrong though).

[@mopitt1687]

I was thinking of doing this method, too. When was your building built? Which dimensions/thickness did you take for the battens? Which plasterboard did you choose? Thx in advance for your r esponse.

[@bertharius9518]

@@mopitt1687 Well, the original house was built in 1900 but I bought it in 2017. I started and finished the renovation work late last year. I was aware that there would be moisture continuously penetrating the wall - particularly when it rained - as the room was over 2 metres below ground. The wall itself was stone and brick. The framework battens were Wickes Treated Sawn Timber - 47mm x 47mm x 2.4m with the horizontal battens secured to the wall with corrosion-resistant screws. The battens had to be thick enough to support wall cabinets. I had also cut into strips some pvc sheeting and I then glued these strips to the back of the horizontal battens to stop the wood coming into direct contact with the damp wall. It's important to have both horizontal and vertical battens fitted so that the air can circulate freely over the entire wall. The plasterboard used was Knauf Moisture Panel Tapered Edge - 12.5mm x 1.2m x 2.4m, sold by Wickes. The plasterboard was eventually tiled over. I didn't fit the plasterboard down to the floor - it stopped about 30cm above the floor and this gap provided a 'vent' for air to enter the cavity. It was the same at the top of the wall but both gaps were to be hidden by cabinets so that was fine. (The cabinets had discreet vents fitted). If you are covering the battens entirely in plasterboard then of course a number of sizeable vents is essential. However, these vents, in my opinion, would negate the use of insulation but in my case that's absolutely fine. To insulate the wall and keep the vents would be like insulating a door that's left open - pointless. Hope this helps.

[@mopitt1687]

Dear@@bertharius9518 Thank you so much, that helps a lot and fits to my previous ideas. I have almost the same situation here in France... Late 1900s and the cellar is about 2.7m under ground level. Moisture problems are reasonable but they exist and get worse. I plan to pour some limecrete aditionally, that we can actually use the space. Thanks again 👍

[@mopitt1687]

@@bertharius9518 are you sure, you meant really 30cm? Or 30mm 😉 60cm 'vents' in total are definitely adequate! Right now I can't imagine how this would look like in our case... i'll figure something out!

[@bertharius9518]

​@@mopitt1687 There are base cabinets (which already have backboards) placed in front of this wall. These cabinets are 90cm high so the plasterboard behind them can finish 30cm from the floor (or 3 or 10 or 20 or 50 - doesn't matter, it won't be seen) but in this case the back of the cabinets still have 60cm to 'rest' upon. Discreet vents are placed in the plinth ('kickboard' in the US) so the air travels under the cabinets and up through the wall gap. The ventilation at the top of the wall is only 5cm high and just above the wall cabinets; the height means these ventilation gaps aren't seen. Of course, if you climbed a stepladder then yes, you'd see them. So it's all worked out fine.

[@accesszero4803]

Glad u done this video, am just about to use it in my kitchen and some rentals to stop the sulphate come through from the chimney next door

[@SkillBuilder]

It is great for that and will also stop stains on chimney breasts

[@spankysmp]

This is a cracking channel - been subbed for a while despite being a no-hoper DIY person. We got our cellar tanked up about 20 years ago as it wasn't that wet. Just storage and a 'cave' Few issues started cropping up recently - salts coming through the plaster but nothing major. What was the slurry you said you used? I might give that a go or look at the Drybase as it's really only spots and not whole walls. Thanks

[@SkillBuilder]

Hi Spanky The slurry comes from Safeguard Europe but it is not good on top of gypsum. You need to hack all that off and put the slurry on the brick. I would look at sticking the membrane on the wall. It looks quite nice as a finished surface.

[@GavinLawrence747]

If the cellar or basement has some elevated moisture levels, are you not better off installing a humidity sensing ventilation system to keep the air moving through the cellar and therefore keep it dry and dry is not cold ?

[@mattmanslim]

Absolutely. This is what Nick Found of Retail Economics recommends.

[@SkillBuilder]

A dehumidifier is essential but look at the fan on the right hand side. That is a 12 inch fan into a coal shute. It would life Marilyn Monroe's dress above her head.

[@nicholasfound]

Hi Matt, Nick here. Agreed. “Hold back” moisture - so where does it go? Nature doesn’t just disappear, even if you can hide the consequences. Moisture will build up behind the cement or membrane, saturate the fabric of the building, and even creep up to the ground floor in serious cases. It really needs a drain if the intention is to block and hold back moisture, as the building will sweat and that will needs channelling somewhere. Otherwise - and particularly for pre-1930s buildings that use softer brickwork which takes on water - using historical techniques and natural materials is the best route, to ‘manage’ moisture (rather than ‘block’) through capillary action and air exchange through good ventilation. By that I mean: limecrete floor, lime plaster, mechanical ventilation, and gentle heating.

[@GavinLawrence747]

@@nicholasfound Excellent post. Am I correct in saying you need to bring air "in" and "out" for a cellar, not just an extractor?

[@blapzroger8970]

@@SkillBuilder I’m not sure this comment is valid or can even be proven, given Marilyn Monroe is dead now.

[@Sunrise-e9p]

I've got issues with a upstairs wall on a gableend, any video on upstairs at all would be great? Love your page by the way.

[@TomTomTomTom538]

Check for leaky guttering or roof tile

[@hannahjames3180]

@@TomTomTomTom538 Yes. Process of elimination. Sometimes it's a simple solution.

[@nedloh17]

Very informative Roger 👏

[@francoisgs1]

can I check what was the product you place first to have the wall to crystallize and seal the wall ?? Thanks

[@TomTomTomTom538]

You've blocked the moisture from appearing, but it's still there, how will you stop it creeping up and causing more problems in the future?

[@SkillBuilder]

Brick below ground will always be wet. There is a slate damp proof course at the top so nothing has changed.

[@joejoey316]

Top job Roger!

[@scotthenry3401]

CT 1 has been a favourite of mine for a long time now, it just works, good for almost everything! Is a very good glue for rubber ive found, which is hard to find something that will glue various types of rubber and is flexible

[@paulthomas3841]

That looks Great

[@viankalobosvalenzuela7456]

Excelente video 👍 👏

[@malcolmfunnell4501]

You always take the environment into account , and it’s impact of the property this is missed by 99.9 % of all builders , it’s the most important consideration overlooked

[@aklouslibby563]

Hi Malcolm l was just wondering if you could kindly help me out, l live in an old barn conversion here in Tipperary Ireland and I have a back bedroom and I have noticed for sure that I get a small bit of condensation on the back wall so I be scratching my head I'm looking up things and the internet and on the wall there is glass emulsion so healed it all off with a wall scraper and I have not had any condensation on the walls for nearly 4 months now but I have made a little mess on the walls with the wallpaper scraper so I was just wondering just for future reference is there such a condensation plaster mix that I could use to skim the wall and also to help with the condensation if it comes back ok my friend I look forward to hearing from you sorry for picking you out only you sound like you know what you're on with ok take care now , YOUR'S TRULY KLOUS LIBBY

[@ChrisHow]

Bloody hell Dylan, that editing at the start was tight, I thought I was either watching Philip deFranco by mistake or I'd had a mini-stroke

[@ChrisHow]

Just joking mate, not criticising! I guess Rog was rambling and you had to cut it out 😂

[@DylanGarton]

@@ChrisHow We didn't have any b-roll for this bit so it's a bumpy ride for sure. I know when the editor gets a mention we're in trouble. My son Abe has joined the Skill Builder team and this one is a joint effort so I can blame him 😆

[@johnpaulmawa4808]

Where can I get the membrane and all the other stuff needed to get this done?

[@lisahill1207]

HI Roger, I have a 1900s solid stone walled house with lime mortar and lime render on the outside which is in good condition on inspection. However the previous owners had a damp issue on the inside i stripped off the wallpaper and found they had used normal plaster over the top of the lime this was wet in places and crumbled off. I have took it back to stone now need to consider plastering. I would like to use insulated plasterboard but how would i fix this to the stone work and keep the wall breathable but allowing no moisture to come through internally?

[@ranxxerox6407]

Looks like I’m asking a similar question. I saw a roger video where he painted a substance called Stormdry??? This appears to stop water being soaked into the brick but allow breathability. I’m looking at this with tanking slurry directly onto the break,treated battened wood frame onto brick with PIR insulation in between and then King span K118 on top. However, every house is different and every situation is different

[@goesbysteve]

What happens to the water though! If it’s coming into the wall but prevented coming through to the tanking can it damage the wall or mortar? I have a concrete block garage which has a wall below grade that gets a little damp. I like the idea of an internal solution but worried I’d just be hiding the issue behind a barrier.

[@SkillBuilder]

Bricks do not fall apart because they are wet.

[@Hew.Jarsol]

Same question and concerns. Just Masking it!

[@MichaelPickles]

I'm a DIY'er I'm thinking after watching all these videos,. How do people get Roger to come and do work for them? Every time I have a job I need to do, I always end up watching Rodger! Today's job is cutting a basement concrete floor, digging up and tanking the wall then putting a draining for it. He makes things look so easy...

[@francoisgs1]

what to place first against the wall to stop all humidity or wetness coming through before placing the cloth material? the outside of the wall is against soil which cant be dig out thanks

[@F0DZILLA]

Hi Roger, did you apply a PVC adhesive to the membrane before apply the plaster?

[@comfortablynumb8832]

Hi I’m moving into a converted barn with walls that contain a lot of salts due to livestock urine causing damp, would this system work

[@Urmza]

We in Northern Europe tend to put a geomembrane and insulation on the outside of foundation.

[@SkillBuilder]

We do now but these houses are 100 years old

[@rachefa]

Is it an outside wall? Please ?

[@Sabiandude]

Can you use the membrane externally. I'm looking to stop water ingress through one side of my house, the water is coming in through the bricks below ground level. I've been told I could do a couple of things. Some have told me to dig down and lay a membrane against the wall below ground level followed by a concrete base around the edge (essentially under pinning in a way). Some have said to dig down and apply an external tanking slurry against the wall and then just backfill it and possible add a french drain around the edge of my house. A few solutions i'm happy to try myself but don't want to make the issue worse. I want to try an avoid doing anything on the inside as it would mean listing up a wooden flooring and there really isn't much room to work with.

[@michellecook5084]

i have bricks outside on my 1970 garage the dpm is same level as concrete floor put bitumen paint on it last year but 1 course of bricks above the bitumen are soaking wet slabs are way under dpm but garage still letting in water any ideas plz

[@PaulSmith-rd8yc]

This would be a bit overkill by doing a single skin garage. Any suggestions before I’ve polystyrene and ply the inside cheap fix really. I’m blind and want to turn my garage into my new hobby of Green Woodworking workshop also a single skin garage I’ve painted the walls inside when I first moved in a few years ago but need to try them out a bit so it doesn’t get moisture traps between full story in the hall. What would you suggest

[@philgormley4652]

your a legend

[@eidolonfilmsukuk8456]

Is there any info on how thick the plaster can be applied to.this? Thanks

[@SkillBuilder]

There is no information because it depends upon the bond with the adhesive, I am quite happy to put a coat of bonding on there and a coat of skim so maybe 12mm in total. Some people dot and dab plasterboard.

[@eidolonfilmsukuk8456]

@@SkillBuilder I think I'd need to apply it thicker than that, so I'm not sure if this would work for me. I'm not sure how much weight the membrane can hold. I'm in a very precise depth due to doors being in the corners.

[@bluestar.8938]

Thank you : )

[@SuperiorEggplant]

A comment worth considering about how "sealed up" our houses need to be these days; Your cooking, showering and even breathing produces litres of water vapour every day. If the building doesn't have a strategy for how to handle that, it's got a problem. If it has a solution to that problem (which it must) then it can also handle evaporative moisture from a breathable wall. If you keep that wall wet, it will always be cold. A cold wall attracts condensation.

[@SkillBuilder]

I agree but I did say, if other methods are not suitable. A cellar would be one. I think I prefaced it by saying I prefer to stop damp from the outside.

[@tualakierna8893]

Would this be suitable for a period property which needs to breath?

[@SkillBuilder]

If the moisture can escape to the outside then it is ideal.

[@tualakierna8893]

@@SkillBuilder thanks so much for your reply! Will it not cause a damp layer behind the dry flex like something you mentioned in another video? I think the issue is rising/penetrating damp. Cold/wet walls, crumbling paint and plaster, mould and condensation.

[@slackmouth]

The Sika 1 render system in my opinion is a belt and braces system to go for,apply 3 x 6mm coats of render for walls and floor , all corners and junctions get a hypalon bandage installed because you are using a cementitious product and is liable to crack at junctions.Sump and pump systems with sheet drain mean there is always maintenance to be taken in to consideration.

[@SkillBuilder]

I am a fan of the Sika system but I don't think it is intended to resist hydraulic pressure. I have also seen it done badly because an 18mm thick coat of render that loses adhesion with the brickwork is a problem

[@jonmould2946]

@@SkillBuilder I'm building an air gap from the outside of the bacement so the earth don't touch the walls and putting a gutter on top however still letting air in. I've taken off the tanking and use it to reinforce the air gap outside. I'll let you know if it works as the building is very old and I can't fine many people doing it this way.

[@Sunrise-e9p]

Can this be used on a upstairs gable end bedroom wall?

[@SkillBuilder]

yes

[@AlastairGibb-sn1vc]

If the damp is now tanked/trapped in the wall...how long until the wall rots?

[@SkillBuilder]

Why would it rot? Bricks do not rot in damp. Roman structures built of brick and buried for 2000 years are still fine

[@owendavies4716]

The damp over the slurry would be condensation, easily sorted by using a renovating plaster over the top of the slurry

[@SkillBuilder]

If it were condensation I don't understand why it appeared in random patches and then completely dissapeared. A rennovating plaster is good but it absorbs the moisture and then lets it evaporate, I think that would lead to a build up of mould in a cellar. It is all tricky stuff

[@owendavies4716]

@@SkillBuilder I think, it would appear on the coldest part of the wall. I was told by a sovereign chemicals rep that because the slurry is so waterproof and cold, the condensation appears on top of the slurry. We have incidents in the past where we didn't really know what we were doing, dot and dabbed over slurry and all the dabs were visible as damp through the plasterboard. Solved by using a coat of renovating plaster then dot and dab over that. 👌

[@Retro-cabin]

Did you remove the paint as slurry’s and crystalline slurry need to be applied direct to the substrate. The crystals react and migrate into the wall to block the capillary’s.

[@SkillBuilder]

Yes it won't go over pain. In my case the bricks were painted so I scabbled them back to bare brick and then painted two coats of slurry on the wall.

[@ranxxerox6407]

Hi Roger, quick question if I may. On the front of my solid wall terrace, there is no front garden (straight onto pavement) with a cellar underneath (along with unblocked coal grate!) I have added left-over knauf 200mm wool insulation under the floorboards (in-between the rafters) which had made some difference to the temperature of the room but recently (after LOTS of rain) the front wall in the room felt wet to touch (we have some kind of plaster wallpaper that has texture onto it) Would just adding tanking slurry (back to brick) stop the water ingress, or would you recommend the drybase flex membrane? I am looking to go back to brick, batten along with DPM, PIR insulation between the battens and then K118 on top to help with the really cold walls. Yet another great video

[@SkillBuilder]

What is on the outside of the wall?

[@ranxxerox6407]

@@SkillBuilder Nothing. There was old style dyno rods (drilled into brick some 20 years ago) but nothing with regards to external insulation. Also the wall is north facing so only getting sunlight in the summer

[@primeHeretic]

What's this crystalline slurry stuff? I have a cheap garage where the floor gets damp and is slowly ruining stuff I store in there, maybe I could use this on the floor as an initial water proofing layer?

[@SkillBuilder]

I don't think you need that product. You can get a two pack damp proof membrane that you mix up and paint on with a roller. It is very easy to apply and you can put a self leveller over it or anything else. Look at this www.setcrete.co.uk/wp-content/uploads/2017/05/technical.dpm_.en_.pdf

[@picking11111]

Not sure if you’ll get this question video you did a few years ago my question is can get a equivalent flex adhesive. The one you recommend is quite expensive

[@SkillBuilder]

Yes you can use another cement based tile adhesive but this adhesive has waterproofing built in.

[@picking11111]

@@SkillBuilder can I use this one and add a water proof in the cement? Mapei Floor & Wall Tile Adhesive 20kg Grey

[@leecraggs4137]

could you just vapour board it afterwards to make

[@leecraggs4137]

asking as looking to something similar

[@SkillBuilder]

yes I am going to try something like that in another location. I think tile backer board stuck to the wall would work well.

[@dave1secondago]

brilliant vid and info SB

[@tommoevans7240]

This fella is having mould on his plasterboards, internal, not been up long on a thick stone wall no cavity all over the wall.. it's cold ect hasnt had heat in a while, will it go or is there something we can do?

[@SkillBuilder]

If the building is drying out you need to get as much air through it as possible. I woud get a cheap dehumidifier in there.

[@GavinLawrence747]

Whats that wire hanging out that conduit above your head Roger?

[@paulthomas3841]

Wire is for the Kettle

[@SkillBuilder]

I like to liven the set up a bit

[@scoot5078]

How does he manage to get his hands so dirty.

[@george4vIogging]

Blimey Mr Bisby... How did you manage to look 5 years younger at the end of the video?

[@SkillBuilder]

Don't tell me that. I have seen flowers come into the most glorious bloom just before they die.

[@george4vIogging]

@@SkillBuilder God forbid Sir! Long way to go yet. I am looking forward to teaching my kids with your videos on holograms and Virtual reality.

[@ricos1497]

@@george4vIogging I don't think Roger needs to be alive for that though. I've actually own the rights to virtual Roger and I can confirm that he'll be doing videos long after his death in June.

[@monkeytonker4637]

Hi Rodger have u watched the heat geeks reaction video to your heart pump thoughts. They are getting hammered in the comments section. One of them even wears his cap back to front.

[@SkillBuilder]

Hi Monkey Yes that video has boosted their channel no end. Actually they agree with most of what I said and their latest video is really addressing a lot of the points I made in a more intelligent way. They also said that they have been trying to contact me but I chickened out. They sent one email back in August which slipped past me. We are going to see them in a few weeks and will be able to video a good friendly chat to try and establish some facts. As for wearing his cap back to front................

[@billybright5038]

Watch out Rodger had this stuff come off the wall before !! Absolute nightmare product !!

[@SkillBuilder]

Yes it needs to be stuck on but so does everything.

[@billybright5038]

@@SkillBuilder Honestly If it was just on one job I’d understand it, but I’ve had it fail in 4-5 different applications on different masonry backgrounds etc. I’d be very wary as in 6-12 months the plaster starts cracking and pealing.

[@nickhaley4663]

Crikey Roger, you don't half get some horrible jobs. That's one i'd run a mile from.

[@mrretired2715]

Prob cost 1000s

[@jackwardley3626]

protect it by not plastering it with gypsum

[@Garyck88]

What would you use instead of gypsum on damp walls?

[@SuperiorEggplant]

@@Garyck88 Hot lime pointed brick/stone work, with a lime-hemp plaster. it's a lost cause though because it takes too long for modern builders, and slapping on a cementious slurry is faster. The external wall will stay soaking wet though - not only sucking up heat (you ever try to stay warm in wet clothes?) but will spall when it freezes and fail.

[@jackwardley3626]

@@Garyck88 hack off whatever is there and moisture causing the damp will dry then re plaster with lime use a limewash paint finish or something a long the lines instead of plastic paints

[@Hew.Jarsol]

Isn't this just masking the issue? The damp is still there but masked? Where does the damp go? Like a dam holding back water..

[@SkillBuilder]

If you can dig down and put the barrier on the outside then fine but it is hard to do sometimes.

[@sasa1982uk]

Water proof layer except around the socket Jk

[@SkillBuilder]

That is above ground.No issue there

[@johndufton9686]

The thumbnail for the video makes it look like Roger has a very long nose.

[@SkillBuilder]

Is there something wrong with long noses. Don't be nosist.

[@johnarizona3820]

^5

[@LongNThickWithEase]

Why don’t you get some 1 who can plaster to do your plastering? That finish looks shocking. Fair play for trying though

[@SkillBuilder]

Plasterers are the easiest people on the planet to wind up. I suppose it is something to do with staring at a wall for half your life.