How to fit insulation 2023 to the latest Building regulations Part L

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In this video I show you How to fit Insulation
This is in my opinion a showcase of how we should be insulating for absolute energy efficiency and getting the best performance from a building or new structure. We designed the roof at the big Build to make the insulation work more cost effectively and produce less waste and ultimately save money.
Please feel free to ask questions in the comments and I will do my best to answer some of them.
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[@ukconstruction]

Follow me on Instagram search Robin Clevett

[@craig5832]

Would 100mm PIR between rafters + 40mm phenolic over the top good enough for the new regs with gapotape? also I wish this gapotape was a bit cheaper 😂 Space is very tight in this retrofit

[@ukconstruction]

@@craig5832 that would be perfect!!

[@smudgesmudger3989]

Robin, I'm a chartered surveyor and construction manager. This is one of the most object lessons in how to properly insulate a roof that I have come across in 35 years of working in the industry. The insulation nightmares I have witnessed are beyond belief and further raise questions as to how the local building control folk signing them off as acceptable. Many thanks for the good work and fabulous videos.

[@ukconstruction]

Thats for your message, I really appreciate you watching my video and taking the time to comment! Let's hope that we can all drive for better standards in the future!!

[@eminencerecords6049]

Hi I’m doing a building surveying degree do you have any job opportunities please

[@richardgallagher4880]

And this is why the average house price is 300k🙄

[@tomcardale5596]

@@richardgallagher4880 the value of most houses in the UK is driven by availability more than the cost of building it. The building cost might make up 1/3rd the cost if you're lucky. Making planning less restrictive and building standards higher and everyone wins.

[@johnovegas]

what about venting the valley rafters..

[@buck8441]

Brilliant job, if only all builder’s aimed for your standard of workmanship.

[@Jimjam2912]

Let me guess ,you went with the cheapest quote and got what you paid for

[@davecowan9466]

@@Jimjam2912 You think by not going with the cheapest all builders will then go to his level of detail……delusional if you think that 😂

[@mattmanwaring1308]

Trouble is most having got the time he has

[@baptist18]

Get what you pay for

[@husher5142]

most will do whatever you pay them for

[@davetaylor4741]

You are the industry poster boy for British standards. Over and above the call of duty. My issue is always cost. Time is expensive. Materials expensive. That posh saw is a Festool. Mega expensive. Never made the sort of money to have Festool anything. Personally I have issues with modern regulations and the idea of living in an hermetically sealed box. I don't believe it is good for the structure or the occupants. Roger Bisby made a comment the other day about houses with chimneys and open fires allowing all your moisture and air movement sorted by going up the chimney. The home owners all the healthier for it. Winter and summer in the UK I never shut my windows. Wake up with snow on the bed but never sick. If the regs want all this crap how come the UK hasn't gone the way of the Yanks and spray foam. A lot easier to do all those awkward angles with a spray gun. Either way these processes create their own problems and add extraordinary amounts to the cost of a build. There really is no such thing as affordable housing anymore. To me the initial cost out weighs the benefit. As a young couple starting out having a house that they can comfortably afford and still have a life I think would be more important than buying an over priced super box with an environmentally controlled temperature setting that they had to hock granny to afford. Just gone too far.

[@Oli-tm6hu]

Absolutely top work, it's great to have people like you setting such a fine example. For me the way to take it to the next level would be to demonstrate the same level of workmanship and diligence with insulation products such as wood fibre and cork, which have the added benefit of being biodegradable and non-toxic. It would be really interesting to hear your thoughts on using those kind of materials and even more amazing to see people with your profile and reputation demonstrating their application.

[@hughmarcus1]

Lots of architects & specifiers want PIR because on paper it’s got the best U values. They forget those values were obtained in a lab. Few installers go to the level of detail seen here, so in practice there’s loads of gaps, around which air flows. Thus in practice the PIR is seriously compromised & other solutions would actually give a better result in real world conditions.

[@phoephoe795]

How is the fire-risk on wood-fibre and cork?

[@stephencollins9062]

@@phoephoe795 good it Burns super well

[@lewisvalori2533]

Very informative and useful video! Great work. I just had one question, why don't you set the insulation boards flush with the underside of the rafters? You showed the rafters clad over with thinner insulation board to provide another vapour barrier and prevent thermal bridging, but I just wondered what the purpose of the airgap between the layers of insulation was? I realise you want to leave an airgap on the 'cold' side to the underside of the felt, but are you best to leave a gap between the layers? or can the two touch eachother?

[@LouiseHolland-q5t]

That would be way too easy!

[@kunid]

A couple of things that makes Robin standout amongst other tradesmen, is his meticulous attention to detail (planning layouts with considerations of the materials, minimising waste, installation efficiency), and being a master at creating tools to multiply his productivity. The latter quality shows up repeatedly in his other videos. A true craftsman!

[@TeeTee-zm2re]

You gotta have the big bucks to hire robin clever

[@weeeeehhhhh]

@@TeeTee-zm2re I was thinking of the cost of this work. The gappo tape alone easily added a few thousand to the build, but the money saved in heating, and the comfort of living in a temperature controlled environment is priceless.

[@dragonfitter]

Yeah but he is charging 600 quid a day so it would be

[@SarahMikeChase]

While it saves on insulation doing 450mm centres you get waste on plasterboard🤷🏻‍♂️

[@gibbodive140]

You may wish to move the thermostat to another position in the middle of the room away from the window for more accurate results ? That way it will not be affected by possible direct solar gains or to a less extent marginal cooling from the window/glass ? Excellent work as always. Shame we do not see this level of pride more often.

[@stephencollins7714]

Amazing attention to detail as always, what an absolute credit to the industry you are Robin. I used Gapotape in my self build garden room and it is great for amateurs like myself who cannot hope to achieve the levels of precision that a professional such as yourself does. I found it really challenging to try and minimise waste across metric and imperial materials but can see that it is very achievable with sufficient forethought.

[@ukconstruction]

Much appreciated!

[@bhwhprods]

I’m in the setting out / planning stage of a similar garden room project. Really liking the idea of 450mm centres for wall studs and rafters. But can’t see how this doesn’t leave me cutting the outer sheets of OSB down by about 105mm if boarded horizontally. It seems to me that whatever option you take, you end up with cuts somewhere! But I am preferring the idea of 2 neat cuts on the PIR (giving 3 x 400mm pieces) and a small amount of waste on the OSB. Plus for corners, the 100mm will give me enough for overlaps.

[@paulrogers3814]

If ever there was a game change it’s at 6.00 - 7.00 in the video - absolutely fantastic work Robin 👍 This needs to be shown to builders, architects, designers and specifiers around the world 🌎

[@jacknicholls10]

Just amazing. Do you always put a 25mm insulation barrier on to protect the cold joists affecting the plaster board? Have you left an air gap between the outer skin of the roof behind the main purpose? Thanks again for a great video

[@joshdaviesbespoketimberstr2028]

I've been waiting patiently for this video to come out and it was well worth it. Incredible precision. After watching your earlier videos on the ISC240 and Gapotape I went out and got myself one to insulate our self build barn conversion. Definitely helps, the insulation is a tight fit and the dust is minimised and I can sell the ISC240 on afterwards. However, I wander if people will begin to lean towards warm roof construction in light of new building regs? It will certainly cut down on PIR install time, create a warmer diaphragm (IMO) and neglect the need for (no offence) expensive products like Gapotape. I think in hindsight I would have gone for a warm roof construction. Thanks again RC.

[@ukconstruction]

Super welcome mate!!

[@mastermcgrath2613]

Robin you are brilliant - I just can't get why some comment asking the STUPID questions that if the actually LISTENED you have covered. Those who know the price of everything and the value of nothing - I for one will use this for my future specifications, changing the roof sizing is genius why is 450 not the standard? 🙏🏼 thank you

[@jjames1950]

Would this be the same concept for a suspended floor on the ground floor with a large full house usable basement? As in using the gapotape between the floor joists?

[@funny-video-YouTube-channel]

Good job ! Tape for the gaps is the correct method. Construction material manufacturers are making good money with such tape, because it works !

[@westwonic]

Great job, one question: why is the pushed-in insulation not flush with the bottom of the rafters?

[@williamjamesconstruction7694]

i was wondering this also, along with other commentators, but i guess Robin does not have the time to answer all questions

[@clivewilliams3661]

I have often specified two layers of multifoil to create a warm roof. The top layer is used as a sarking material and the lower layer is fitted under the rafters and up the cheeks to create the 25mm air space between the lower layer and the internal cladding board. If required the cladding board can be an insulation board and/or plasterboard etc. There is no requirement for ventilation of the rafter voids as they are all fully sealed and airtight and because the multifoil is very much a vapour barrier, no moist air from below can get into the space. Using multifoil has the advantage of allowing the depth of the rafters to be as minimal as is structurally necessary since they don't have to accommodate thick insulation and ventlilated air space. therefore, any perceived cost extra of the insulation material is more than offset by the reduction in roof timberwork. Using multifoil also means that it is simple to seal all the joints together rather than having to resort to the complication of specialist tapes. This type of roof insulation is common in Alpine regions and has been successfully used for many years.

[@scotland1380]

@J C and expanding foam

[@edc1569]

The time you spend now will pay back so much over the 100+ year lifetime of this building.

[@MrClem877]

Great work Robin. As a long in the tooth building control surveyor it does my heart good to see you so clearly demonstrating a text book practical method to achieve Reg’s compliance. This sort of guidance should be mandatory viewing if we are serious about creating some quality housing that will meet the new part L standards in June. So often the standards drafted by the govt boffins are lost in translation on site - keep up the good work👍🏻

[@ukconstruction]

Thank you Trevor, I really appreciate your time to view and comment on my video, especially as you are a building control surveyor!! I respect the building regulations and I have always enjoyed working closely with the LABC and some great Approved inspectors too!!

[@handycrowd]

Love that.. "lost in translation", how true. See so many good ideas get bodged on site by folks just chasing the money...

[@j444nsy4]

Mate that set up for the pir cutting was unbelievable. And of course the festool saw. I didn’t see one bit of that yellow dust floating about. It seems long winded the whole set up and tape but I bet it’s so much faster in the long run. True craftsman…… 👌🏻

[@ukconstruction]

Cheers mate!!

[@gregorymartin5720]

Hi Robin. Great video, will definitely be using gapo tape on my next job. Just wondering what fixings you use on the second continuous layer of PIR? Also do you then counter batten or fix the plasterboard through the top layer of PIR straight into the rafters? Cheers, Greg

[@FreddysHamster]

I had that question also.

[@c.ele.]

Hi, did either of you ever get this question answered/finish your jobs and have tips to share on the fixing of the plasterboard?

[@buck8441]

Great job, how I wish all insulation was fitted like that ! , Just a observation, I noticed that the insulation between the rafters was not flush with the face of the rafter, so when the next layer went on was there a air gap between the two insulations….

[@rhysarthur3378]

See this guy is a professional all the people I’ve worked with are the type to just stuff it in and cut corners etc this is guy doing it properly

[@michaelwaite4367]

Hi there I notice you've set the pir about an inch or so not flush from the rafter. Is this the best way?

[@Ireallydunnomuch]

This is so dreamy to someone who has been renovating an old property where all the rafters are at different spacings, many different widths from top to bottom and some a bit twisted too. Every single piece was a custom size and we used a lot of low expansion flexible air tight foam. Nice once done though!

[@williambeard5526]

Hi Robin. Im looking at insulating the roof space on our 1960s ish dormer bunaglow. At present it has no insulation apart from what looks like some wool type insulation thats stuck to the roof membrane and has heavily rotted away over time. The roof is made up of what looks like 3x2 from wall plate to ridge with 120x50 loft floor beams that run from the front to the back of the house for the loft floor and bedroom ceilings. My plan would be to add additional rafters from wall plate to ridge to add extra space so I could use 100mm PIR insulation like you have so I have an air gap and then add another skin as you did for the extra layer also using the gapotape as it looks like a good idea then carry the 100mm over the top of the bedrooms ie the dormer roof in between the rafters, I cant add anymore layers in the bedrooms as I havent the ceiling height over the windows. Very expensive but needs doing. So my question Your first layer of thick PIR, did you push that all the way into the rafters so it touches the roof membrane or did you leave an air gap between the roof membrane and the PIR and did you leave an air gap between both layers of PIR? The PIR against the walls was that pushed all the way to the wall also? Love the videos Robin, always watch yourself and roger always something to learn.

[@KennyEvansUK]

This is what's known in the trade as a 'proper job'. Sadly there are not many out there with Robin's integrity and skill.

[@dragonfitter]

Most of the time people won’t pay for that

[@AfricanSouthernCross]

I’m not a builder but this video is so good to see as a homeowner who wants his or her home warm, thank you so much for taking the t8me to upload this!

[@thechrissyb]

Robin i've always said pir manufacturers are missing a trick by not supplying sheets at 350 wide. For 400 centres. Obviously big sheets would still have there place but it would be worth them doing surely.

[@TheWiccanGirl]

Love the passion and detail you go into. Would there be any benefit to insulating the roof if it was just a standard loft space used for storage, or is it best to just stick to a quilt on the base?

[@waynegaskell]

Informative thank you sir :) - so to close off the air-gap debate, you have an air-gap on the diagonal section of the roof, but on the vertical walls there's no gap and fitted flush ? I do have a scenario myself. I have under house storage with joists at the ceiling leading to the tongue and groove flooring. I keep reading conflicting information on whether an arigap is needed in this instance. What are your thoughts please? (have have 100mm boards waiting to rock n roll) :)

[@ukconstruction]

If there is a ventilated space naturally like a traditional suspended ground floor from air bricks then simply insulate between the joists, I would check with your building inspector if this is official works as even they have differing veiws!!

[@09conrado]

Funny how methods can differ from country to country. This is an excellent job no doubt about that. Here in the Netherlands though I usually see them slap on huge big sheets of PIR on the outside of the roof. As those come glued with a layer of plywood or osb on the outside or even both sides, they next screw on the lattices for the roof tiles and off you go. This is obviously a bit more finicky but not less quality. Just a different take on things I'd say

[@09conrado]

@J C that would be the reason he added a final layer on the inside

[@jdickson242]

I find the praise valid but quite amusing because as every job should be done this well. However based on my experience as an acoustic and air tightness consultant I'd say only 1 in 50 houses are done this well.

[@ukconstruction]

Wow!! Be great to talk more with you and discuss!!

[@keoghrichard1988]

Is it me or does that build have not sockets or lights anywhere! 😅 make installing insulation so easy! 😂

[@ukconstruction]

Yes we run all our electrics after the insulation of the main roof, it's a much better job!!

[@muddyfunker3014]

Amazing channel. Love your skill. The insulation for that roof probably costs more than my house 🤣

[@randymch]

I've just checked how much GapoTape I need to complete my attic room roof. Think I need about £2,000's worth of tape on top of the £5,000 of insulation. Jeepers.

[@chrisbabbitt4202]

This build is looking absolutely brilliant! Well done.

[@pkpropertysolutionsltd701]

It’s a good product but way overpriced for what it is. When buying a box at £95 for 50 linear meters; that wouldn’t cover 3 sheets of pir. It’s quite a hard sell to customers and other builders at that price point, I think it’s worth it but customers always complain about the cost of insulation.

[@ukconstruction]

I thought exactly the same when I first saw the product some years ago, but I have been fitting this type of insulation ever since it was introduced to the domestic market in the early 90s, by using the Gapotape and adopting the methods of construction that I use it takes half the time to install and the saving in labour itself more than covers the capital cost of the Gapotape, also the performance of the PIR with no badly fitting air spaces and gaps means that we can use a thinner PIR and this will also make the install easier and cheaper, it is a real winner of the product, people only see the initial cost and have no idea of the hidden costs of labour and excess energy wasted if fitted badly!

[@pkpropertysolutionsltd701]

@@ukconstruction I do appreciate it is a good product, no doubt a better insulation value. It’s just convincing the client is where I struggle, most customers in my experience are only interested in spending the budget on the things they can see in the final project. A good example is a client of mine that gasped at the cost of the concrete for the foundations but spent £800 on a microwave and £1000 for and espresso machine for the kitchen.

[@andrewgalliver498]

Hi robin, very good video. Steady camera and good sound. Cld i ask sm advice please...i have a newly built single storey extension with a vaulted ceiling. I plan to use the techniques you have outlined in your video as per the insulation. Cld you explain the insulation joint from the cavity wall using Rockwool or similar to the PIR board maintaining the 25mm air gap? I can see in you have built an small PIR upstand from the wall plate to meet the ceiling PIR but is there any more fitting detail behind this to seal with the cavity insulation? Also, i have 4 Velux windows across the width of the roof. The 2 areas directly above the windows, which meet with the house, are not ventilated from the wall plate as the other areas are. My roofer used a breathable membrane. Is this an area to be concerned about and if so could you offer some advice on how to vent these spaces please. Thanks again.Andy. (Swindon,Wilts)

[@andrewgalliver498]

Anybody hv a response to these questions Andrew is asking?

[@videogalore]

Lovely detailing, although as someone on the design side I can assure you that we can't win! It's all about preference of the builder and whichever route I choose the builder will often ask if they can do the opposite as it's what they are more comfortable doing, so it's not like we don't try. On the roof itself, I would be interested to know why you didn't go for a warm roof from the start as it's completely new?

[@ukconstruction]

See my comment about warm pitched roofs in another discussion above mate

[@sallahudinmehuddin8046]

There's no way builders can take shortcuts now, they have to take pictures and show building regs before it can be signed off.

[@nikfish1]

Robin is aging like Benjamin Button.

[@joewentworth7856]

looks great. but i was surprised to see the thick PIR pushed back into the rafters 20 to 30 mm from the face. When you cover this over with 25 mm over sheet does that space not make a convection space? I would think minimising the gap would give better performance?

[@Scott-cm8sv]

Great video, the gapo tape was new to me! The only thing I think you should make clear is how important the ventilation gap is behind the insulation board. The rafters looked to be 200mm (?), so a 100mm board had plenty of space. That’s not always the case and I noticed your guy had pushed the board back at least 50mm in places. With a smaller rafter that would push the board right against the felt. ‘Best practice’ would be to only push the insulation just a little further beyond the bottom edge of the rafter in most situations. This will also avoid having a vented gap top and bottom that will reduce the performance of the insulation layer. That aside, good video 👍👍

[@deanchapple1]

Looks like this client has an unlimited budget! But I guess, you get what you pay for! It’s gonna be one seriously awesome house!

[@ukconstruction]

My Client is on a fixed price for the work and we are never the most expensive.. but usually the most organised and efficient!!

[@christopherhoare9469]

I used the gapo tape for first time few months ago. Really is a game changer.

[@Mikey__R]

I notice the rafters are proud of the insulation between them by what looks like 25mm or so? Does this mean there's going to be a gap between this first skin of insulation when you fix the second skin to the edge of each rafter?

[@acelectricalsecurity]

Why have you done that before it's wired, or aren't you having any power or lighting.

[@ukconstruction]

All our power cables are in viods that are on the warm side of the insulation and fitted once the stud partitions and flat ceiling collars are fitted

[@acelectricalsecurity]

@@ukconstruction as an electrician if I walked into a place and seen that had been done before a cable had been installed, I wouldn't be impressed, it's restricted where cables can be run, and we can only run cables in certain areas, installing the insulation before a cable has gone in, has made a lot harder than it needs to be. Also, had I priced that job off a drawing, I would be assuming the insulation would be going in after it was wired, knowing insulation was going in before would of increased the price of the install.

[@DavidJohnson-yg8qm]

Looking at the standard of workmanship, I think it is about time a degree qualification is available. Superb quality and a good guide to how loft insulation should now be installed. Just putting down rockwool over the ceilings these days is really not good enough is it.

[@SandrAnswers777]

Hear, hear, otherwise a licence to build obtained with proof of certification in craftsmanship

[@archangel6415]

Hi Rubin, why have you ‘recessed’ the insulation that’s fitted between rafters and uprights?

[@denishurley1358]

Hi Robin, Great video. How do you attach the plasterboard after this? Do you screw it into the rafter? How did you attach the outer thinner insulation layer ?

[@BoxerfanUK]

I found it gave a tighter (but still manageable) fit using gapotape just down one side only when going between rafters And plus with the price of gapotape a considerable saving financially.

[@TheTurjan]

sponsored

[@joshdaviesbespoketimberstr2028]

I was planning on doing this, glad it worked

[@dannymcnicholl4151]

That's an amazing job, just wondering what you are doing for lights and sockets there? Should be wires in there for lights and smoke alarms at least, won't make it as handy as that. Great detail on this and your skill build videos , very professional , keep up the good work

[@ukconstruction]

Hi Danny, all our services and cables are on the warm side of our insulation layer, travelling up to ceiling level in our stud partitions etc

[@ifitistobeitisuptome]

Looks amazing!! I just wish I could afford to insulate my house (Victorian Terrace) to that level! The stuff dreams are made of!🙂

[@guyrandom7861]

Amazing craftsmanship and attention to detail. If only building codes were as strict in the states my house wouldn’t be so cold/hot all the time, insulation and proper air sealing is still an afterthought.

[@carlb401]

That is what amazes me with your building codes, the fact that some states don't have any or the fact there is no national standard like here in the UK. Then when some states mainly the colder ones do have codes some do not even require insulation under concrete slabs. Yet here in the uk which is not as cold as the USA, we are require to use a minimum of 100mm / 4 inches of insulation under a concrete slab.

[@eddjordan2399]

cracking job. thats why i like ybs as you stickit over the whole roof then cross batten then any internal voids can be done with rockwool the real stuff. and vapor p board. out of interest how do deal with humidity in your air tight buildings trickle vents and air heat recovery?

[@qwertyuiop124172]

Hello Robin, Brilliant video, beautiful insulation - compliance with latest regulations and above all its looking absolutely beautiful. What was drop in temperature from day to night? Best wishes from Leicester, ENGLAND. Ahmed

[@JamesGarwood]

Hi, I'm doing something similar in my loft, insulating 100mm between the rafters with a 50mm air gap, new membrane and 50mm overboard, did you put a vapour barrier in there before you plasterboarded it? I'm trying to workout if I need a vapour barrier or not, thanks!

[@nastazioromanos9531]

In short, add tons of harmful chemicals to insulate and when the building reaches the end of its lifecycle send it to the landfield. How about using cork or wood chip like Steico - both superior materials provided by nature and cheaper.

[@johnbowmer5698]

Great video, thank you. When the insulation is fitted between the rafters, how do you maintain the uniform gap between it and the breather membrane? How deep does this gap need to be? Finally, the insulation between the rafters sits back from the front edge of the rafters meaning there's a void between the two layers of insulation - is this normal?

[@ukconstruction]

Hi John, we use a timber reference block that we set on the sides of the rafters and we push the PIR back to that point in our application we have a small gap between the PIR between the rafters this is a sealed space and acts a little like double glazing, this is a detail I first used on a previous project that was specified by an insulation consultant

[@johnbowmer5698]

@@ukconstruction Thank you Robin for getting back to me

[@hijackstudios]

If you do have a gap between multiple layers of insulation, the thickness of each layer matters as you don't want the dew point to be in the air gap. Thinner layer goes on the warm side and as usual attention to detail on all air sealing greatly reduces the risk of mold in the gap too.

[@joshddavies]

Hey Robin, you mentioned how taping the joints of the overboarding acts as a vapour barrier. Have you also installed another vapour barrier/vcl as well? I.e the green plastic. Many thanks.

[@garyturnbull254]

Love the idea of 450 centres to make maximum use of the PIR, but does that mean you will lose out when you fit the plasterboard? If p/b is 1200mm wide then you will have to rip it down to 900mm for the joins to be on the studs/rafters - or am I missing something?

[@ukconstruction]

No Gary no plasterboard waste as we use 2700 long boards

[@LondonSoundSystem]

@@ukconstruction Horizontal?

[@MTaylorElectricalServices]

Awesome to see. I steer people well away from spot lights in roofs due to the insulation values. What would be your make up on the dormer cheeks? Thanks

[@stuartbird4933]

Respect you Robin, your a passionate chippy. Always looking outside the box, to us carpenters we never stop learning. Great responsibility comes from knowledge and skills that we pass on. The waste on bringing cold spots (joists)cellotex and plasterboard would be horrific. I think your a top chippy and have learned some good tips from you. Thank you

[@ashleywalshaw99]

Neatest insulating I’ve ever seen

[@amazing451]

Hi Robin, it looks like you guys pushed the first layer of PIR up above the bottom of the rafters by 20mm or so, was this to create a void for services before fixing the layer to the underside of the rafters?

[@harveysmith100]

I have seen your video before about cutting and fitting PIR sheets using Gappo tape. I love your set up and the jigs you use. As I have said before, I am just a rough old trowel but I did a kitchen refurb last month, I made jigs up for drilling for the handles. The customer was amazed at how perfect it all looked when I finished. Thanks for sharing this wisdom Robin. Jigs save time in the long run and reduce stress so much.

[@michalmajercik4957]

That’s how to do it insulation properly.Good job mate 👍

[@93eze2]

The Rob songer of carpentry x

[@missvmartin6571]

Genius. I wish builders took this much care over insulation, I have nightmares trying to get tradesmen to take it seriously - they just think I'm being a silly woman trying to make their life difficult and then I get other things going awry thanks to passive aggressive behaviours. People ask me why I end up doing so much myself - that's why. They seem to think that if one can afford to pay for whatever they are doing, you are going to be OK to pay for the heating and not care about how efficient the insulation is.

[@TeeTee-zm2re]

Most British buk builders are like that. Totally crap

[@oliverfisk4204]

Superb workmanship. As someone working on a significant DIY refurb/conversion, this is a level of quality I would love to aim for. Thanks for sharing.

[@timdickson5531]

Amazing work Robin, such incredible attention to detail and big-picture forward planning. Do your customers know how lucky they are to have you on board? I'd die happy if I was able to knock up a PIR cutting table to your standards, never mind build a house.

[@northeastcorals]

I highly doubt Robin charges average UK chippy rates so I'm guessing his customers will know they have someone next level on board 😅. Completely deserved as you will not see this kind of work on the vast majority of sites, then again the majority of people can't afford it.

[@ianperkins1360]

Hi Robin. I'm enjoying your videos and admire your attention to detail, quality of finish and time-saving methods. I was wondering how you would go about insulating for an old house where purlins are being removed and ceiling collars are required to be bolted to the sides of rafters, and ashlar walls are being installed (I've seen different methods for these including bolting studs individually to the sides of rafters but also birdsmouths cut out of the rafters to sit on the ashlar wall). As you say in the video, it makes insulating a trickier process but is there a method you would favour? Also, would you favour the foil quilt insulation in this case? Any advice would be appreciated.

[@jacannon9147]

Great video and excellent set up for a cutting station I would suggest cross battens on the main roof as it allows water to run down on the felt easier and creates an air gap with the vent strip over Less water on roofing laths Allows for full fill insulation between rafters as well Note increased spacings change design loadings and need to be checked with structural engineers depending on roof coverings Great stuff Robin 👏 👍

[@xbmods7395]

My house is 1930's, tiled directly onto closed boarding....am I right to assume without stripping all the tiles, installing membrane and retiling over battens I can't use foil insulation, but can under loft floor

[@cagdasduran8337]

Do we need to leave an air gap between roof and PIR?

[@ukconstruction]

You need a clear air space that has a vent at the eave and ridge to allow air to pass

[@jamesburtenshaw8421]

Lovely to see the forethought at the design stage to accommodate the insulation. Please could you let me know why you push the cut between boards up past the bottom of the rafter creating a void ? We have always had it flush with the bottom so the two layers touch effectively.

[@harveysmith100]

I will wait for Robin to reply but at a guess, that pocket of air between the layers gives another layer of insulation, a bit like the air between two pains of glass in double glazing. Over to you Robin.

[@markkearney959]

I was thinking the same, he said it was a cold roof design, so that would leave me to believe that a 50mm gap between the insulation and the roof batons would be required??? Once the insulation is pushed past the rafters lower edges, the airflow gap is then reduced. I also think that the gap between the two insulation layers would lead to a possible condensation problem. Just my thoughts and also Intrested in Robins response. It does look a good job👍

[@IrelandConstruction]

The void is minimal and will not condensate as the ecoterm insulated board is also a vapor barrier. By not leaving a small void you could possible end up with a few humps on the internal surface. 👍 This is truly a masterclass from Robyn. 👌

[@partytime3778]

I must admit your workmanship is superb. All these regulations keep changing and at the end of the day are we just adding to make more problems in the future. Just get the balance wrong and years down the road, dry rot. I noticed your guy pushed the PIR into the rafters and recessed them about half to one inch further than the face edge. If you put another insulation flush with the rafter there is going to be a gap between the two insulation from top to bottom of the roof. Will moisture build up between that gap. I'm insulating my loft at the moment and have done it the same way as you, now I wonder if the PIR should be pushed in, flush with the rafter edge so it's touching the other insulation.

[@ukconstruction]

there will always be a gap just by the nature of the PIR not being that flat or the way it holds when pushed in, this small air space acts more like a double glazed unit according to an engineer that designed a structure for me some time back and I tend to do this most times, as far as moisture.... the moisture should not really get past the vapour barrier that is formed by either a dedicated membrane, or in our case a really well installed under rafter PIR That is well taped etc

[@MorrisseyOner]

I live in Texas on the gulf coast. Our insulation is only on the floor of the attic. Can i just keep the foam boards/radiant barrier as whole and screw them to the wood, which would leave channels for air flow? my goal is just to keep the attic from being 140 degrees F and help the AC work easier.

[@Oli_Hudson]

10:13 You went a bit northern old lady there Robin!!! Great video and tips as usual. Cheers

[@mikesenior1333]

If a loft was plasterboarded years ago and is used as an a sore room but now want to use as an occassional office... can the gap between the tile felt and plasterboard be filled with insulation somehow. There is cheap aluminium backed bubble wrap sheet only in between and you guessed it...hot in 2 days of summer...cold in winter. Is it worth the effort if its only used a few times a month?

[@paulbishop4005]

Minimizing surface area reduces heat loss. In this case insulation above ceiling rather than just up to the roof ridge.

[@TheTurjan]

we’re are the joist hanger on the velux frame mate ? , aswell 10mm gap between the refter and celotex that’s a proper laugh 😂 celotex shoul be perfectly tight from rafter to rafeter , then you apply the foil tape (aluminium tape) .

[@ukconstruction]

Maybe you can explain exactly what the regs say about the positions of various layers and types of insulation? We do a calculation of how our materials perform based on how we will apply them, if you feel that I am missing something please enlighten me and the professionals that I employ who advise me?? Its really easy to put across a view or opinion like you have now maybe explain in detail your criticism??

[@coldt1484]

You are correct about the gap, it shouldn't be there.

[@davideyres955]

That’s pretty much what I want to do in my place which is a purpose built chalet. from the flat roof up in to the pitched roof and back down again. All I’ve got so far is people not understanding what I want to do and only wanting to fit what they want to fit. I want the loft space to be dry and warm as I use it to store stuff that I don’t want to get ruined.

[@bbashers]

This is absolutely the best way to do roofs, unlike my current 3year old roof build which was a shoddy as your "how noyt to do it" piece and still signed off by NHBC!

[@naratipmath]

Look very neat! The problem is that this type of tidy work is probably not affordable to most people.

[@ukconstruction]

I am usually not the most expensive my clients inform me, I just plan stuff better than some builders and do the work myself!!!

[@antony28hort]

Cheapest is never the best

[@mule666]

So much passion for the trade i rarley see..

[@daniel__clark]

Are there any alternatives to gapotape? Gapotape seems to be priced from.a monopolistic position at the moment.

[@mathewmaguire2487]

Have just priced up Gapotape for my new roof - £1130🤣

[@rossmcleod9818]

I think robin may have a sponsor 🤔

[@joshdaviesbespoketimberstr2028]

What about foil taping Underfloor Heating Edge Insulation roll to the edges?

[@rodgerq]

When you consider how long that'll be in there and doing the job of better insulating the space, I imagine it'll pay for itself eventually in saved energy costs.

[@adamquick8748]

Hi Robin, what’s your thoughts on using super foil insulation instead of PIR ?

[@ukconstruction]

I have tried it but I'm still really keen on the performance of the PIR I have a property that is rooms in the roof with multifoils that I built some years ago and it performs "ok" but I also have a property very similar in size with PIR and the difference is noticeable, people often use multifoils as its meant to be easier to fit, I reckon that PIR with a decent set up is easier

[@philipoakley5498]

Lovely video of some great techniques. My only query was that when inserting the insulation slabs between the rafters it looked as if they were pushed in past the flush position that would leave ~10-20 mm gap when the second insulation was applied. Is that gap designed in, planned or desired? I was expecting the the two would be 'kissing' each other.

[@Multiboxes]

I thought the same. In other videos I’ve seen it’s fitted flush with the outer edge.

[@andrewscaramanga5860]

Great work but also a lot of work, so much easier and better to blow cellulose fiber (recycled newspaper). A bit more depth required to achieve equivalent u values.

[@anthonyboyd4016]

Hi robin how do we price this product into our jobs and win the jobs with out comeing across too expensive as theres always builders out there that will cut corners to win jobs i would love to use this product but i dont think most costomers would pay how could i overcome this problem with the industry i have just done a vaulted celing on a extension i have just built brilliant tip on the table we managed to replicate your table just with out the festool insulation cutter ❤😊

[@brendansherlock6442]

Nanny state nonsense all these standards and specifications, meanwhile, first time buyers can't afford a property mortgages defaulting, homelessness increasing. Will yee tell the regulators to f off

[@RichCowie]

Great video, very informative. Could I ask, what discs do you recommend for holding on the unbridged insulation sheets to the walls? Thanks

[@ukconstruction]

We use the small discs that you use for soft wetroom panels

[@chrisjames1924]

I’ve been doing a Victorian property with roof still in place. It has non breathable bitumen felt so I’ve left a 50mm gap. Would you put holes in ridge board for air to pass over from eaves to eaves? Also, when placing PIR boards between rafters do you push them down to the top of floor joists or do you cut around the end joist to let the board make contact with wall plate? It’s weird installing insulation with a roof still on. Not something I’m used to! With cost of living crisis there will be a lot of people with older properties tackling this by themselves and if you don’t get ventilation correct you can wreak havoc with the integrity of your roof. It’s a minefield with older properties.

[@Festivejelly]

Presumably the insulation between the beams doesnt go flush against the fabric? How do you maintain a gap?

[@TheStevenWhiting]

Its alright, when I asked Building Control recently "Did you actually see the steels put in? See them in place so you know they are correct before you signed it off" I was told "No, we rarely see any steel go in as the builder normally has already covered it up" well then don't sign it off them. For all you know, they could be lying.

[@christaylor5291]

Take photographs as proof, must cover yourself in all eventualities.

[@lukethompson5227]

I think you mean steel.

[@TheStevenWhiting]

@@lukethompson5227 Yep. Keep mixing them up :)

[@4321nugget]

Do you need a vented ridge tile between each Raffer as the air can't move along the ridge as blocked by wood?

[@shaggythesheep]

Fantastic video Robin. I have a similar question to wotnoturbo regarding the Velux windows - do they not prevent airflow in the rafters that they span as there's no longer a direct route from wall plate to ridge? Or is not something to be concerned about? I am currently planning to replace a flat roof in a kitchen with a pitched roof with Velux windows in so this video was very timely, thanks again.

[@ukconstruction]

They can restrict air flow but generally there is sufficient air leakage around the window above the insulation level to enable some ventilation to pass

[@shaggythesheep]

@@ukconstruction Thanks, that's great to hear. Appreciate the speedy reply

[@eddyz67]

instead of expensive gapotape could Expansion Joint Filler Foam rolls be used with aluminium tape

[@thenovicenoisemaker]

Ideally I’d like to avoid using combustible Euroclass ‘E’ rated products. Preferably try and get to STA ‘C’ standard for all that timber too. Appreciate not everyone cares about fire and fire load in their home though