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

[@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..

[@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🤷🏻‍♂️

[@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

[@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

[@RichiRothschild]

I'm a property developer.. And this is the cleanest loft site, i have ever seen 💎

[@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!

[@bhwh_h]

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.

[@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!

[@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!

[@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 🌎

[@christopherhoare9469]

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

[@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

[@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 !

[@terrymanthorpe1454]

Your work makes me fill like a cowboy even though I was trained by Taylor Woodrow , in my tool bag was a Canadian distance saw, saw set an a saw file , claw hammer Nail bar, hand brace , wheel brace nail punch and a bro ll for masonry holes , yanky screwdriver , wooden mallet jack plain and block plain , roofing square , combination square , bevel and l level , plumb bob and a set of chisels , and a big tub of tallow , animal fat , and a pencil, can you imagine if a tool thief broke into my van , I really can’t think what he would take , probably the bottles of beer ,, love your show and thank you 🙏

[@ukconstruction]

Your no cowboy!! just being able to identify some of your tools let alone be able to use them is a real skill!! Thanks for watching and commenting, from one fellow carpenter to another.

[@terrymanthorpe1454]

I forgot my coping saw and Spoke shave , I remember when I got my first estwing hammer with the leather handle, I took it to bed with me and when I made my own frog and walked around the site as a tradesman I was very proud, I’m now retired and it’s loverly to watch the new generation ‘ I did the stair case for what they call the Franklin hotel now in knightsbridge ; it was two stair wells from basement to roof , all by hand and I did all the first and second fix for the Control tower Gatwick were I parked my car outside the control tower and Brighton to London in one hour with my tools on a motor cycle , as wages were amazing I ended up with owning six house , I loved carpenter , but it never made the money I made on property,

[@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….

[@noumanali343]

Impressive work I am working last 2 years in the UK as a structural engineer I have a lot of issues with the builder regarding the regulation. They did not follow the regulations for saving the cost but you give very good lesson quality is the best key to success.

[@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...

[@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

[@King-Arthur-The-First]

Fantastically professional. Thank you so much. For this video.

[@ukconstruction]

You're very welcome!

[@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

[@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

[@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 👍👍

[@mariusgheta2141]

BRILIANT JOB, thank you very much for all information, you have a good day!

[@brianlopez8855]

I have done the board insulation and every board is cut to size with rafters at 400 centres 350 gaps to meet each rafter space. E It is dirty dusty job but worth doing properly., I never use the tape as they are trimmed and trimmed until they fit tight and stay in of their own accord. Nice looking job Robin.

[@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.

[@chrisgemmix0815]

I do love jigs too!

[@amanuelablel3364]

Your voice says it all, so passionate, wish all builders had that attitude

[@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.

[@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!

[@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!

[@sb544]

Look at the quality of this guys workmanship - Unreal

[@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.

[@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.

[@steamsearcher]

I am working in 100 mm PIR to most of our 70 year old house. Aslo much Multifoil. So far the Gas supplier is not happy... Dec to January at £10.00 is not funny to them. Yes our roof is the very last to loose the snow when we get some. Many walls still to do. Lovely video. Love the bench. Bodgeit and Scarper Reading.

[@Happytruth]

That a great job I’ve done this in the past and had nightmares getting the stuff in and for that reason I don’t bother doing these kind of jobs anymore they’re hassle and it’s getting worse for trades with the new rules. That stuff is terrible to use it gets on your chest and no doubt in years to come it’ll be another health issue that was said to be safe!

[@MikeDawsonArt]

That is next level expert thinking. Love it!

[@ukconstruction]

Thanks Mike!!

[@TheBarnylondon]

Ha Robin .... Im Barny we a bit of work together maybe 32 odd year ago over banstead way , glad to see you still at it as am i , but more chilled now. i did a huge loft about 6 years back and it was passed to use tried-iso which was totally wrapped inside being very careful to do as per. The loft has stayed warm in winter and cool in summer , the heating costs rose in proportion to the size and no vapour issues. I reckon it saved me a week in labour time . Its a shame the councils don't like it . Cheers barny

[@ukconstruction]

Hi Barney!! Great to hear from you!! Its been a long time for sure!! I have used foil wrapped roll insulation like Tri-iso before and in some retro fit situations it the only way!! Its good on top of the rafters too, be good to bump into you mate at some point!!

[@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!!

[@davidlawlor4317]

I was a big fan of cutting the PIR crooked with a rusty Spear and Jackson before stamping it between the rafters.

[@grahamdavidson9492]

Amazing attention to detail and consideration for using up material to reduce wastage, costs and the environment. Not seen Robins work before but that was enlightening and what the whole building industry should be considering for every element of house building.

[@ukconstruction]

Thank you Graham!!!!

[@duncanabbot8352]

Brilliant! I am about to do an extension and now I know a lot more about the insulation challenges. Thank you.

[@jesshothersall]

Thank you for such a thorough explanation of everything!

[@ukconstruction]

You are so welcome!

[@neilnash2383]

Really great workmanship absolutely amazing

[@mykehoole5787]

I really enjoyed this video, it’s great to see your attention to detail especially the compound cuts you made on the PIR and the way you minimised wastage. The old adage of “If it looks right, it probably is right” comes to mind and the finished result looked very good. If only all builders were as conscientious. The Bluetooth connected thermometer you used is a great tool, I keep one in my caravan to trend the temperature and humidity to monitor it over winter.

[@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

[@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?

[@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?

[@geoffbell4895]

Very good but I was hoping on guidance regarding need to an air gap ( kingspan suggest 50mm) between insulation and underside of roof tiles or felt if fitted. My project involves insulation an old property.

[@chrisbabbitt4202]

This build is looking absolutely brilliant! Well done.

[@jackofspades69]

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

[@DelH555]

If I ever build another home I know exactly who I want to build it! Your eye for detail is plainly remarkable and would embarrass even the best of builders knocking about the country. Also I found this video one of the most satisfying yet, yes I know it is only insulation but I bet you could heat that roof space with 4 wax candles in the winter time! Beautiful work.

[@ukconstruction]

Wow, thank you!🙂

[@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.

[@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

[@ooooobpbpbpooooo]

Love your videos, and the commitment to doing a thorough job. I'm learning about roofing and intrigued by the differences of opinion between experts when it comes to cold and hybrid roofs, regarding running of cables and air ventilation. In this video, the between-rafters PIR is installed a few mm back into the void from the rafter edge, and it is mentioned a second PIR layer will be added across all rafters internally. - Is this to run cables? - What will happen to air moisture between the PIR layers? Thanks!

[@robgardiner2343]

Everyone would love this type of finish a job.. as a builder of 30 years it's easy spending other people's money.. Mr builder come into the real world..

[@ukconstruction]

Hi Rob, I still can do my work competitively indeed I was not the most expensive price this client had, the difference is we get well set up and the work is profitable for us and more economical for my clients, all our work is on a price we just choose to do the best we can

[@marlonlake511]

I'm just insulating my raffter now with 50mm insulating leaving a 50mm gap and noticed getting alot of condensation on roof felt what is breathable and plenty of airflow from eves

[@ukconstruction]

I suspect that warm air is making its way onto the cold side this happens a lot, maybe have a good look and see if there are any large gaps from the heated side of the construction??

[@JimJimpmjj]

What a truly skilled craftsman you are sir, Fantastic attention to detail. Just a pleasure to watch, and thank you for sharing your knowledge and information 👍👍👍👍👍🍻

[@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!!

[@noahleno]

What an beautiful job you did there. Such attention to detail. Your years of experience and love of the craft make it look so easy. So inspiring, great work!!

[@ukconstruction]

Thank you so much!

[@trimley]

Superb job when I think back to only last year on sites

[@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

[@thetessellater9163]

When I started my career, it was 50mm of fibreglass wool in between rafters; never saw rockwool until a few years in !!

[@westwonic]

The house I bought in 1991 was built in 1959, and had 25mm (1 inch) thick fibreglass insulation between the ceiling joints.

[@chardonian1]

Brilliant.As I've said before 'The Clevett Standard'!!!! Cheers Robin

[@oussamaelhussein4367]

Amazing honest builder.. 👏

[@ukconstruction]

Thanks 🙂

[@michalmajercik4957]

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

[@djsconstruction9448]

Hi Robin I follow longtime great work really appreciate all your efforts thanks

[@keithburton7516]

Very clever to put 450 centres in. Never seen such attention to detail on insulation. Expect no less that that from you though. Thanks for showing us how to do it correctly. I like spray foam myself. Love your passion and skill.

[@utensil999]

Just watched this a second time. Excellent stuff robin.

[@Oli_Hudson]

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

[@sirpatrickspens]

I’m in Australia where most houses don’t even have insulation as regulations are about 40 years behind the UK, and the most common comment I’ve heard over the years is, “it doesn’t get cold enough for insulation” … they seriously hadn’t even considered it for heat resistance. Anyway, my quick question is what do you have in the underside of the roof tiles? I can see something but not sure what it is. Assuming it’s some kind of membrane and I won’t be able to remove tiles, any idea how I can install something like that - or can I do without it??

[@tonywinters403]

Bravo! Love the data collection to back it up.

[@fiercefix]

Really can't see many builders doing this job to this spec. I think getting a firm in to spray foam the lot like they do on canal boats is the answer to this ball ache of a job. Fair play to you for your top work here.

[@antonfit4health]

Thank you Robin set out clearly the standard I will be specifying for my re roof and re insulation to latest standards , Great video , clear explanation and good camera work , Anton

[@seven4seven]

Forget submitting photos of your workmanship, this video is evidence enough for the building regs!

[@ukconstruction]

Nice one mate!!!

[@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.

[@paulbishop4005]

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

[@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?

[@gusolive]

THAT WAS AWESOME!

[@theNeathBoy]

Love watching Robin’s vids. Planning to the extent whereby you minimise wastage by getting the beams the correct widths is chess grandmaster levels of forward planning. Several moves ahead of most people.

[@DZTechNet]

Outstanding comprehensive presentation, well done!!

[@ukconstruction]

Thank you!!🙂🙂

[@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

[@baz28k]

Amazing workmanship and attention to detail, with explanations and demonstrations on how it should be done. Great stuff!

[@ukconstruction]

Awesome, thank you!

[@kolgrillarn]

Well, wood lives, expansion and shrinkage so there will be leak of heat. That means moisture in winter when we have+22 inside and might be -25 celsius outside. Leave 1cm on every side and fill it up with sprayfoam and its completely air tight.

[@ukconstruction]

Hi Roger, in the laboratory tests the method you described was also tested and in reality it is very difficult to completely foam fill the sides of the insulation sheets thus leaving large cold spots, foam also looses some of its strength and rigidity and becomes weaker, the Gapotape has an encapsulated memory foam that compresses really well and if you get the fit right it will allow for the marginal expansion that you mention no problem, also try holding a board in position that has a 1cm gap all round???

[@kolgrillarn]

Thanks for your answer! I made our second floor warm about 22 years ago like i explained and still good! Keeping a board in the right position was no problem and i am no builder.🤓 A few splines across the truss and if needed in between the board and truss till you come to that point with foam , take off and foam the rest😊. Maybe we have better material here?? "Made in Finland" 😎

[@fintan2830]

A fine example of how to do a job properly. Building Control Officer's take note!

[@belucky9630]

What happens when you cut the lights in? Do you cut the whole bit of insulation out for the lights? Interesting to see what needs to be done?

[@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

[@therabman_5606]

top class work. Always learn something in each of your videos. Thanks for sharing 👍🏻

[@AntonyGoodall]

Your approach and executive really is first class. What a joy to watch a master craftsman at work. Thanks for sharing and talking us through it.

[@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

[@brandonwhitham2105]

This is outstanding quality of workmanship!

[@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?

[@keithtraa]

WOW! I'm impressed! Very Good job!

[@jeremysaunders9916]

Great to see a real professional at work with attention to detail 👏

[@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 ?

[@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. 👌

[@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.

[@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

[@alexandercrump2298]

@robin top man, top quality job

[@Howt-ooo]

Pure class. Enough said.

[@ukconstruction]

Thank you Richard!!

[@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.

[@shaunglendinning]

Great video Lads! That's the way roofs and lofts should be insulated, Well done!