Using Adhesive Foam To Attach Insulated Plasterboard

[@AliDymock]

0:00 Intro 0:17 Prep work 2:45 Solid vs Cavity Walls 3:54 Internal vs External insulation 5:26 Options for Internal Insulation 7:01 Building Regs & U-value 8:12 Options for Attaching Insulated Plasterboard 8:42 Attaching with Insta-Stik Foam 11:26 Mechanical fixings 11:56 Window Reveals 12:30 Finishing Touches 13:04 Outro

[@mariandanrotaru579]

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[@henrywaterhouse6291]

I've been using instastik for around 12 years, some tips would be to spray the board and wall with water prior to applying the foam, you get greater adhesion, apply foam between the edges of the boards to stop cold bridging. Also a more cost effective way is to use kingspan or similar board, then stick the plaster board to the kingspan. I've gone up-to 100mm kingspan with 15mm megadeco plaster boards. Bathroom walls have a load of around 100kg per 8x4 area that I have done. The key is a light waterspray for bonding and on old walls I use sbr bond on the walls. One last tip would be when sticking the plaster boards is when you butt them up together just twist a plasterboard screw between the sheets every 300-400mm the small amount of hold stops the sheet your sticking from expanding past the previous one and keeps them flush.

[@garethheathcote4988]

I love insta stick it sticks almost anything and goes off quickly it's great for giving skirting etc. We insulated loads of houses for housing associations with 100mm insulation backed plasterboard and fixed it using insta stick with a couple of concrete screws to hold it tight against the existing plaster it was a really good earner. Your meant to return it around the corner something like a minimum of 150mm though it do performs quite well without that. Nice tip advising people to put some foam in the edges btw. 👍😀

[@AliDymock]

Good stuff Kevin. How well does Insta Stik stick to foil would you say?

[@AliDymock]

I wouldn't want to be the guy who has to pull off the skirting down the line! It's amazing how strong it is!

[@henrywaterhouse6291]

@@AliDymock very well, I have over 100kg per 8x4 board all stuck on the foil. The key is a light waterspray to increase the bond. Using kingspan, you get a better U value, less wastage and it's cheaper than a bonded insulation/ plaster board.

[@Matt.ffgmatHexPulseChain]

Hi I have a plan to buy 20mm pir board two side silver foil (£20/each) and 9.5mm plasterboard (£10/each) then I have a plan to stick them together. Then cost is a half price (£60-65 shop price ) This diy plasterboard I have plan to stick from inside to empty cavity wall ( build in1965 ) What’s your advice, it’s good idea?? Thanks

[@CH-hl7nv]

I seem to be following behind your life experiences in some regards, I used your videos to build my garden room 2 years ago, and when I just searched for 'sticking insulated plasterboard', up you popped with the goods! 😅 Much appreciated, your videos are always well presented, informative and very very helpful.

[@marcovianwd]

Good video! Curious to know if you saw any noticeable benefits since you completed the project a year ago and been through a winter to measure the difference before and after? Thanks , I’m thinking of doing the same .

[@thpxs0554]

Great video . I did a whole house like you’ve done here during a refurb. Insta-stik is incredibly strong. You can literally stick almost anything to anything and it’s not coming apart. It’s much quicker and cleaner than board adhesive dot and dab. You can get 2-3 boards from a can so it’s just slightly better value as well. It locks the wall boards to the ceilings, as the Victorian properties have mostly settled out of square and the inevitable gaps can be fully filled and locked together for the plasterer to tape over. No movement cracks later. But you need to bear in mind that the foam will continue to push a bit for quite a few minutes after it’s stuck the board, so care needs to be taken not to get a step against the adjacent board. It looks and smells like low expansion foam but it’s unbelievably strong once it’s cured. It can be tempting to use it where you shouldn’t really. It’s excellent on skirtings and architraves as well. No drilling and filling. Much much better than no-nails.

[@AliDymock]

Yeh it is amazing stuff and it's interesting how the comments have differed vs dot and dab though that is often the case when a newer way of doing things comes about. I think it would be great on skirting but I wouldn't want to be the guy who has to pull the skirting off down the line.

[@Musicman1001]

@@AliDymock I’m looking at using your video as a proof of concept to do a couple of walls in our kitchen. Reckon once the mechanical fixings are up, that it’ll be strong enough to hang kitchen cabinets off?

[@TheFakeyCakeMaker]

@@Musicman1001 someone in another comment said you'll definitely need mechanical fixings of doing this in a kitchen where cupboards are going to be hung.

[@timothyvenn4193]

Nicely explained, really competent analysis of interstitial condensation and well described. So many other diy dot and dabbers getting this wrong. Congratulations. (Ex architect and lecturer in construction technology)

[@mbiggs89]

I'm looking at doing exactly this once I move into my new place and in all my research hadn't seen the foam as an option. Always helpful to see well presented alternatives, thanks!

[@AliDymock]

Snap, but I’d heard it worked and given the paper backing it should be no different to regular foam attached plasterboard. We’ll see though. I’ll update as the room progresses!

[@Jackzuk]

Silka plasterboard foam might be an option too, its amazing stuff and the nozzle is really good, ive had left over stuff and used it 2months later no problem, i have a form gun but after lots of use its pretty gunked up now, tried cleaning it but i think its too far gone, so the silka nozzle was a nice surprise.

[@1myfriendjohn]

Great work man, I ended up going the stud wall route using CLS16 and 50mm PIR with a 12.5mm board on. This was on a late 1800's property. I put strips of DPC on every timber that was touching the wall and had an air gap between the wall and insulation (about 10-15mm on average) I was surpised how much noise it actually cut out just by doing this let alone how warm it was.

[@bbar182]

You could also use minimal gap expansion foam between the timbers to prevent cold bridging and eventual decay.

[@TheRealAristocrates]

I'm very interested to see whether this is still performing as desired after a couple of years. This is almost exactly what I need to specify for a job I'm working on, so it would definitely be good to know whether it worked out well.

[@johnriggs4929]

I've only ever used mechanical fixing on insulated plasterboard, after seeing a job where it had been dot and dabbed with plasterboard adhesive and the plasterboard had later become detached from the polystyrene. I've always used 6mm sds drill, red plugs, then 65mm aluminium nails (which hold in plugs better than you'd imagine.) You have to use a bit of scrim over the nail heads due to the compressibility of the insulation, otherwise the heads may pop occasionally. But I must admit, this looks like a feasible solution that would be a hell of a lot quicker. I'll give it a go next time I have some to do.

[@welcome2jamrok]

I come from a construction background, started from the architectural design field up to PM on big jobs. I do alot of DIY at home myself as i have an understanding of how it all goes together considering i would usually specify it on drawings. Im too lazy to document my work but if i did, it would be exactly like this, well done, really like the attention to detail and numbers according to the manufacturer. Subbed.

[@AliDymock]

Welcome to the channel Norman! I’ve always found PMs to be very knowledgeable across a broad range of trades, big picture types but with an eye for detail. I’m only a DIYer so I’m learning and documenting as I go. No calamities so far 🤣🤞

[@alexmousley7213]

Nice tutorial and analysis. I had damp issues in my Victorian house in the alcoves so built a stud wall with 50mm gap from the wall then celotex insulation and plasterboard. I also vented behind the stud wall with holes in the suspended floor and going up through the ceiling and the same above. I found that I didn't need a plasterer by carefully filling all gaps with caulk then polyfiller to level, cross lining with lining paper and using a top layer of textured paper. If the costs of heating keep going up, I may sacrifice more interior space with another layer of insulated plasterboard!

[@michaelchristensen2621]

Hi Ali, thanks for a great video. Can I ask, if you are getting a new EPC certificate for this house, do they check if it's done by a certified installer or do they accept DIY jobs and presume it's installed as per product manual? Thanks

[@LifeOptimise]

No they don't check any certificates, just ask what has been done.

[@arronth]

Interesting video, very good how you give a run down of all the options and your reasoning. I live in a 1930's semi with solid brick walls, a few years ago I internally insulated all the of external walls with battens and 50mm of PIR insulation between in much the same way the walls in your garden room are constructed, and it has made a marked difference in the comfort level of our house as well as the heating costs, which are now significantly lower. It was however, a huge amount of work, especially as we hacked off all of the original lime plaster (it was loose it places anyway) to maximise room space. Keep up the good work!

[@AliDymock]

Sounds like a very solid job. This was a lazy way of doing it and a bit of a test but it’s worked well for now, we’ll see how it fairs before I do the next room 👍

[@bockersjv]

Amazing. Two videos that will be of great interest as in the coming months as i have both these jobs to do. 👍🏻

[@AliDymock]

Great stuff John!

[@Reef_Club_]

Superb! I found Knauf technical to be really helpful when I was selecting the insulated board for our renovation. They were happy to provide a u-value calc and dew point analysis via email - no fee or anything. Great service.

[@Swwils]

Shame that knaufs full range is really hard to get ahold of in the UK!

[@icg6534]

If you had removed the plaster board on the front wall would that have saved you a significant thickness? Thank you for a superb and very clear description.

[@tomkelly6238]

Love the upgrade to flip flops when you might step on a gripper rod or staple 🤣

[@AliDymock]

😆 I should probably set a better example...

[@stepbackandthink]

I've started using this gun adhesive and I really like it. You need to be aware that the foam can slightly push out the plasterboard as it cures. Also, spray the board laying on the floor exactly as you did in the video. If you try to spray it onto the wall it just makes a big mess. You definitely need mechanical fixings if using this in a kitchen where they might be wall cabinets.

[@Daisy-wy5mn]

Guns are a game changer

[@Hew.Jarsol]

Which mechanical fixings? Or plasterboard screws into battens through the PIR?

[@willo219]

ah man, this was a really good video, was just looking for the next one where you do the window cills etc and you never made one 😢

[@ryanchattaman1333]

Hi,just wondering how your getting on with the insulated plasterboard,if you’ve had any issues and if it made a difference with keeping your house warm?

[@keefykeef]

You're a braver man than I removing that rad!! Great work

[@alanbuoyant9848]

Any condensation problems a few years later?

[@takleteck7008]

Great vid that's given me the confidence to have a go myself - thank you! I'm probably wasting my time because you don't seem to answer questions but here goes... You mentioned the concern of damp by creating a cold inner wall, but I've missed the part that explains what you did to mitigate that problem please or did you simply take the risk?

[@francismartin6073]

Does foam adhesive reduce air cavities behind the insulation board and thereby reduce amount of condensation/mould?

[@nicks4934]

I did a baton frame of 2x1’’ with 400mm centres with 50mm kingspan filling. Then put a visquin sheet across the whole wall to stop moisture, then plaster board.

[@Hew.Jarsol]

Good idea.

[@saracen4622]

Hi. Would you say foil backed plasterbourd be sufficient for the same use. I.e external inside wall?

[@bartgeerts2845]

Good video. How did you prevent moisture migrating and condensing around the wooden beams? I'm doing a similar job but I'm afraid that the wood in the walls will rot because of this excessive moisture.

[@Hew.Jarsol]

DPC behind the battens.

[@Swwils]

Did you check the vapour resistance of the boards you used? Depending on the thermal value of the construction it may not be enough to stop condensation, lots of these insulated boards claim water vapour control even though they have quite poor water vapour performance or no dedicated vapour control layer at all - general suppliers also tend to get this mixed up.

[@jve]

Can you recommend a board with suitable VCL ? I thought most were foil backed - is this not enough?

[@Swwils]

@@jve Knauf Thermal Laminate Vapour Check

[@jve]

@@Swwils thank you. I could only find these in polystyrene version, not PIR. I see other vendors have vapour barriers that are to build regs standards e.g. Recticel supply a PIR / plasterboard with vapour barrier (Eurothane PL) that conforms to EN ISO 10456. Have you come across these?

[@Swwils]

@@jve You just need to make sure that you are actually getting what you need, there are two main vapour resistance values used so it can be quite confusing. Your supplier might not know the difference - if in doubt contact the manufacturers technical team directly, they will be of massive help. You'll see typical boards like XPS that has no vapour control layer with a resistance like 12.8 MNs/g or even the regular thermal laminate that has no resistance at all but then ones with vapour control layers will be around 80 to 150 MNs/g like PIR laminate.

[@charlesstafford3385]

Nice job you can always put a washer before hammering in the mechanical fixing

[@azza1793]

From my experience i would not use dob n dab on foil faced pir foam backed plasterboard as the adhesion between the foil face and the dob n dab mixture may seem sufficient initially i have found that it will separate after a short period of time.

[@AliDymock]

That's exactly what I thought. Having a paper back is smart from GTEC.

[@driftingoffgrid9573]

Glad to have found more from you after following your Garden Workshop Series! Great blend of instruction and rationale.

[@pdb-t6g]

Being a solid wall from the 1920’s have you got lime mortar solid walls? We’re looking to internally insulate our 1890’s cottage but been advised repeatedly by preservation companies not to use gypsum plasterboard or create a vapour barrier on the external solid walls. We’ve been told the solid walls need to breath. Going with a wood fibre board and a lime plaster finish to avoid any damp issues later. Really interested to see how the insulated plasterboard works out for you. Cheers for the video.

[@rich3633]

I think you are generally ok with gypsum if you have a damp proof course thus helping the wall above it to stay dry. In old buildings with no dpc the walls can contain considerably more moisture and need to breathe, lime plaster allows this while gyp doesn't. Also consider the paint over the plaster as this will need to be permeable as well and lots of modern paints aren't. Full disclosure I'm not an expert.

[@dipalisen]

I have been advised the same solid wall needs to breathe. I thought of why not use good roofing membrane on the solid brick wall which is breathable and acts as a water vapour barrier on the wall then batten up and use rockwool (insulated and breathable) Inbetween then use moisture plasterboard used for bathrooms?

[@woodworks2123]

Good video. Precise and to the point.

[@dalison1]

Great video mate. Very informative and great editing. Well done

[@blackpoolrox6475]

A great, detailed and informative video. Thanks for posting!

[@philis1966]

Been using it for over 10 yrs.brilliant stuff

[@LondonStuff.]

Great video. Thanks! Will this solution work for a loft conversion where there’s one side wall which is party wall to next doors loft (unconverted)?

[@trimmxx2169]

How do you find it now any issues?. I'm worried there wouldn't be enough ventilation behind to allow the brick to dry out ?

[@mxlyzer]

Can I tile this board when fixed this way? Would it hold the weight of the tiles in a bathroom? Thanks

[@mijalic1]

Great job. Thank you for the time and effort you took to make this video and share it with us. Greetings from Croatia.

[@AliDymock]

Croatia is lovely, you lucky chap. Glad the vid helped.

[@Dmoriarty1993]

A nice video with great information. Subscribed.

[@gemhad]

I'd like to do this in my bathroom and apply over existing plaster which has been painted. Would it be best to remove the existing paint before installing the thermal plasterboard?

[@Dave5843-d9m]

You need to pull up (or cut) the floorboards at the wall to be insulated and insulate between the timbers using PIR. The cold bridge on the uninsulated bricks will cause condensation, black mould and potentially rotted floor beams. Rockwool will not help in this situation. You can cut wall the insulation board to a loose fit between the beams and use spray foam to fill the gaps all around. The radiator upstand pipes can be replaced with Hep2O allowing a neat connection without solder. Use an inline stop valve to isolate the pipe under the floor. When the system is depressurised you can make one cut and lose virtually no water. Use a block style cutter and have the valve ready to quickly push on. Keep a wet vac handy to clean up spills but you probably wont need it.

[@neojted]

Good point. Have you seen mould or rotten floor beams in practice after internally insulating a wall? If so, how long afterwards?

[@nakita1959]

Amazing work and thanks so much for sharing your knowledge

[@davidgray7204]

I was advised by my council to fit tantalised timber on the wall first and 72.5 insulated plasterboard, what's your take on that?

[@mrwang420]

what if you just paint the brick with some like acrylic paint so there is a liquid barrier? Paint is thin. or even paint the brick with clear epoxy?

[@johnmorrissey1675]

Hi just one thing you should do is around the window , leave the slab over hang beyond the reveals ,then later trim the foam only from the back with a craft knife , cut your slab infill around the window and foam in place when all is dry cut off excess slab around window giving you a slab to slab corner , hope you can follow , important to avoid cold bridge at window reveals 👍

[@AliDymock]

Yep understood definitely the best way to go. The problem I had is that I didn't have room for plasterboard, insulated or otherwise over the plaster and getting the plaster off seemed really difficult (might need to get myself an SDS drill). And then I can see it all being ripped off anyway if/when the windows are replaced. Might try it on the next room though!

[@Hew.Jarsol]

Can't you just screw plasterboard screws through the PIR into the battens behind? Then tape up joints..?

[@benny4legs]

I've read that moisture can travel from outside inwards through the wall. Is this something you considered? I think there are special coatings that can be painted on to the exterior which will stop water getting in but allow moisture to escape. Thanks for the video :)

[@fernandombay]

What adhesive to use for sticking PIR to Plasterboard?

[@SoulThrasher]

Great videos you are making, so after 2 years how is it going with the walls?

[@nikquatty]

Hi I have cavity walls but my north front facing room is pretty cold and Gable wall is cold to touch can I just put these Thermal plasterboards like you have ? Or is condensation going to be a problem?

[@AliDymock]

You should be okay to do so, I can't think of a reason off the top of my head why moisture would be any more of an issue with a cavity vs a solid wall

[@nikquatty]

@@AliDymock have you noticed a difference now since fitting the boards.

[@loracle540]

Do you think this method would be good for the ceiling?

[@eaminslim52]

Such a useful vid, thanks Ali. Anyone see any issues with tiling over this type of system? with the extra fixings it should be plenty strong enough for a grout and tile finish in a bathroom right?

[@barrysmith5466]

Next time you remove a radiator,after screwing down the thermostatic valve fit a blank to the outlet because they have a frost stat in the valve and they can open up if it gets cold and flood the room.

[@AliDymock]

Thanks Barry, did not know that!

[@mikeheasman2594]

To make a blank, rap some ptfe tape round 5p piece. Place inside a nut and screw on to valve body.

[@Stratoszero]

Do you have a video of adding insulated board to a bay window? Mine has ancient expanded poly tiles over the insides of the solid stone window mullions. This looks terrible and the joints/gaps encourage mould. However Im not sure how to mitre the boards to fit?

[@glenwilkins8587]

Hi Ali. I'm looking to do this in the next few months. Can I hide a gas pipe in the insulation,by cutting a channel out the back of a panel. Great video. 👍

[@tmanoharanify]

This is a great video. Thank you. I have one question, i do get condensation on the wall. So for that i would need the wood baton option rather than direct adhesive option?

[@AliDymock]

It's hard to say because you may be getting condensation because the wall is cold. Once you've insulated it will be warm so the condensation will be gone. So as long as the foam sticks well enough to begin with (or dot and dab cement stuff) then you may be totally fine doing this may way. I think that because the boards have a vapour barrier between the insulation and plasterboard this will also help reduce the water vapour from getting to the brick wall in the first place so I reckon it's totally fine BUT do use acoustic sealant on the joins and also around the edges. I've had no problems yet, the wall is plastered and painted and I'll be doing the next room the same way this month :)

[@tmanoharanify]

Thank you. I will let you know how it goes. And good luck with room project!

[@avomarkarian6187]

What’s the brand of the boards ?

[@mrwright5699]

Could you stick on acoustic boards using the foam and would it work to deaden the sound more than drywall adhesive or fixings? Possibly 2 layers of acoustic plasterboard?

[@Dave5843-d9m]

You need to use the thermostat vale stop cap. If you simply screw it to zero there's always the risk a bout of cold will open the valve.

[@user-cn1em2qx6f]

i noticed you lift a litttle gap at the bottom and sealed. could i leave a bigger gap if i wanted to. say about 100mm.

[@westwardquest]

Thanks for making this video, I've found it really useful. How many canisters of insta-stick did it require for a wall this size?

[@nanay7701]

How did you add the radiator to the insulated plasterboard?

[@georgerothwell]

Great video, about to undertake the same job in my own house

[@antobeer]

Hello, Great video. Is it not necessary to bring it back to brick when doing this job? I’m going to undertake this in my sons room

[@vishal1746]

Can I use this insulated plaster board & form to seal for my garage wall ? Garage wall made single wall ( 2 side ) & other side made up with block Will that helps ?

[@joemorris1282]

Such a super helpful video thank you! I've just done the same in our living room following some of your instructions. Just wondered though and I've already done the same as you but now I'm second guessing myself, would the capping off of the insulation with plasterboard at the window reveals be a point at which vapour could pass behind? I'm hoping I don't need to rip off the plasterboard I've fixed here! 😂

[@aaaaa4266]

Does the plaster go on fine over the joints were u applied the acoustic sealant

[@tomek]

10:15 Question, you mention a continuous line of foam. Could I ask what the thinking behind that is? I was once told to only do vertical lines, so any moisture that could be in the brick and would condense between brick and insulation - can trickle down the wall. Would it be better to trap air in there, or to create a cavity of sorts?

[@AliDymock]

👍 sure, this goes for dot and dab too, so my understanding is that: 1) you want to stop any water vapour getting through the joints between the plasterboard getting behind the sheets and condensing. If it does get behind and at least it’s confined to just behind the joints. 2) There may be a small vacuum element to it too: once dried air would have to get in for the board to fall off. 3) possibly for fire reasons, to slow spread of flame up and across the wall.

[@mikeheasman2594]

Solid line of dot/dab around board edges and accessories is to maintain fire protection.

[@simonc513]

Your videos are so good! Full of such good information. Well done 👏👏

[@AliDymock]

Thanks Simon, glad you like!

[@alipaulstagram]

Did this to our Victorian bedroom a few months ago! I had a few added complications, namely having to replace all the double glazing and dealing with a bay window. Cutting that insulated plasterboard at a perfect angle is quite the challenge! Otherwise you did pretty much the same as me. Great work.

[@AliDymock]

Sounds like it's holding up nicely. I have a half-hexagon bay window downstairs and was wondering how easy it is cut the angles. God to know it's doable, well done 👍

[@alipaulstagram]

@@AliDymock I used a digital angle finder to work out roughly the angle to cut. It doesn't help the the original walls, ceiling and floor were all wonky so I needed to use a lot more foam at the bottom to get the boards plumb. Fill any big gaps with more foam to prevent thermal bridging and slap on some bonding to make up any significant gaps.

[@SA-vz7qi]

Curious that you described Phelonic Core as better insulator than PIR. I had a look and the thermal conductivity seem almost exactly the same. Curious what is really the difference.

[@paulnewman3283]

Hello, the link to the plasterboard is expired. Can you confirm what plasterboard you used exactly? Maybe a new link or the full name please?

[@rafaljaniczek8202]

Could you tell me what about damp moisture membrane / you did closed air pockets via using foam as square on plasterboard I think personally you should put foam horizontal to plasterboard however due to high moisture density in air after few years it could create damp in between plasterboard and wall. I have done this using silka mulitpor is not cheap however no possible to create damp as you actually extended natural wall breathing

[@johncooper3607]

Any update on how this has worked? I thought it was best practice to take up the flooring and have the insulated board go all the way down to the top of the ceiling below, you have left a big gap under the floor board area so would be nice to know what its been like 1 year down the road... Cheers

[@Tom-Lahaye]

I agree with the fact that there are a lot of cowboys on the market just wanting to scavenge on government subsidies for insulating your house. A thorough bit of research is needed and will pay off if you're going to hire someone to do the job for you. I'm planning to have my exterior walls insulated from the outside and rendered, this is a real specialist job and I chose to go with a builder which already has 20+ years of experience with the process and offers 20 years of guarantee on his work! So worth the extra bit of money. The other companies which were invited to make an offer trough one of these websites were you can get 5 offers didn't even reply back, so they probably considered the job as too complicated for them because of some technical details of the house. Another advantage of the chosen builder is that he can do some structural changes on supporting walls at the same time, so it isn't necessary to have two different companies having to work in each way or at different times. But as for the easier jobs, I agree on the fact that getting the government subsidy does not cover the added cost for labour when outsourcing, as one of the requirements is that the job must be done by a certified company, so you're still saving money when doing it yourself without getting the subsidy.

[@AliDymock]

Good work, totally worth getting the best to do that kind of work.

[@antobeer]

How much warmer did room feel?

[@Banjoba]

Great vid. Really helpful!.How thick is the line of foam when installing it to the wall?. 10mm?

[@johnnynephrite6147]

is that stuff the same as drywall? sorry not familiar with this material.

[@Musicman1001]

How did the corners hold up to cracking where you've used the flexible sealant? I'm going to get my walls skimmed and the plasterer is recommending scrimming the corners.

[@psandbergnz]

Don't the isulated boards have a foil backing? If so, how are managing to stick them onto the masonry wall?

[@ravk5266]

I did it today and it works with the foam adhesive. It sets quickly so be sure to only wait 2min once finishing foaming the board up before sticking

[@AndrewHelgeCox]

I don't see how this is a continuous vapour barrier if the foil is on the back and the acoustic sealer is on the front, with a porous material and the thin air gap of the crack where panels abut between the two airtight elements. I may be missing something though. Thanks for sharing your experience as always.

[@nasir_glasgow5274]

great video and well detailed , thanks

[@bbar182]

Hi there, i know you posted this 2 years ago wondering if you can offer some advice. How is it holding up and have you had any issues with this type of technique? ie condensation or mould forming? Lastly has it helped make the room a bit warmer?

[@barringtonsmythe3464]

Excellent Ali. Really informative

[@stevedavies7170]

I Want to do this in my daughter’s room. I have a couple of questions if hats ok. 1) Do you only need to do the outer walls? I was planning on doing all 4 internal walls in her room but if I don’t need to then i can save money! 2) I saw on another video about foam insulation where they advised to have a gap between the insulation and the wall to prevent condensation. (I’m going to have to take the plaster off as it’s in a mess) is it safe to stick it straight onto the brickwork without a gap? Thank you

[@jablot5054]

You can insulate internal walls for sound but it's not really needed. It's better to have an air gap and vapour barrier to external walls.

[@annkelly398]

Hi.there, I follow you on KZbin and really need some advice if you've time.... We've just had a garden room installed and our man has been following you too so we were really assured things went great. Plastering has been done and we're now not sure whether we've painted too soon after, even though the walls looked dry but might have felt cool to the touch. We went for it 5 days after plastering and mist painted it and then 3 coats of emulsion later. However, the french doors and window is very steamy and very drippy with condensation. We still have final fix electrics so have an extension lead with two radiators on and the window open for 2 days now and still the condensation remains. Can you offer any reassurance to us that it is normal or that we've messed up painting it too soon?

[@AliDymock]

Sorry for the delay in replying. I'm sure this is down to either the deepest layers of plaster still drying or your mist coat which will have been water heavy so I bet the condensation problem has gone now :)

[@ranxxerox6407]

Great video, just what im looking to do. Question? Isn't a dryliner track required with solid walls?

[@Happytruth]

One problem you can get doing this is before you put insulated boards on you can see if you have water or damp coming through the walls but once you have stuck insulated plasterboards on you will never know and in those cases you can get black mould form behind the insulated plasterboard. If your pointing outside is all good you may be fine but if it’s a single 9 inch brick wall you may get penetrating damp, if the wall has a cavity you should be fine unless the cavity is bridged anywhere, remember black mould is a living organism and you only need a small patch and soon the whole back of the boards will be covered.

[@adrianred236]

Good tip with emptying the rad. Just a note re cavity insulation from the 80 ( and 90 and even into the early 00s) only a lawyer of about 50 mm would likely have been added, still leaving a 50mm cavity which can still be filled to greatly improved the overall insulation. The cavity insulation would originally have been installed by the block/brick layers and could often have been poorly done as they would have been working around wall ties which caused gaps. The insulation would also have been low density polystyrene.

[@AliDymock]

Great bit of info! That would be the best starting place for insulation if that is the case.

[@mrv5801]

hey ali - can u explain how u fitted the radiator brackets back - as the insulated plasterboard is not strong enuff to hold that much weight right??? which fixings did u use to fix the rad brackets???

[@MadAsBagOfMonkeys]

I'm thinking of insulating our brick to brick 'annex' on our ex council house and will probably use the solution I used earlier on a plasterboard wall in a converted attic - simply glue on two strip wood pieces say 2" x 1/4" where the radiator brackets are to go and use five short screws to attach each bracket, took a double radiator 60cm by 80cm no problem.

[@mrv5801]

@@MadAsBagOfMonkeys i thought 150mm screws (or coach screws) screwed thru the insulated plasterboard & into the brick would be ok???

[@MadAsBagOfMonkeys]

@@mrv5801 bit overkill, as I say, the 2inch by 1/4 inch by 1 foot lengths glued on to where the brackets will fit and plenty of 3/4 inch screws will hold any decent sized radiator. took a heffty radiator I put on in a simple one thickness plaster board 'wall' in my attic five years ago. Sure a PIR backed plaster board will be even stronger. Didn't want any metal screwed in to a cold wall to bridge that'd bridge the insulation?

[@tonym992]

Very well explained. Thank you 👍

[@jamesjeffery6139]

I may have missed it as I was clicking through impatiently but how did you finish the reveals? just bond plasterboard over the edge of the boards and across the internal face of the window reveal, butted up against the window itself?

[@AliDymock]

It's in the vid, briefly but I just did the edges of the insulated plasterboard to be butted up against the existing plaster on the window reveal. That does mean therw window reveal is a thermal break which isn't ideal but to put insulated plasterboard either you lose your window frame, replace the window with a smaller one or before you start making the window opening wider - big job and make interfere with the lintel. So I think the way I did was best. As for cutting it back after it's stuck rather than before - I found it more accurate doing it that way. i've done this job again in the next bedroom and did it the same way.

[@dipalisen]

Any opinions would be appreciated on my idea thanks, if it will work? As solid walls need to breathe. I thought of why not use good Quality roofing membrane (Foil will sweat with vapour) on the solid brick wall which is breathable and acts as a water vapour barrier on the wall then batten up and use rockwool (insulated and breathable) Inbetween then use moisture plasterboard used for bathrooms? No condensation inside + warm wall and breathable brick wall. Good / Bad ?

[@AliDymock]

Umm so the problem is that water vapour will still hit the breathable membrane (if you have writing side facing inwards then yes it will work as a vapour barrier) and then you'll get condensation. You always want the vapour barrier on the INSIDE of the insulation, never the outside. The roofing paper/membranes are not the same, they act to shed water that may get behind the tiles whilst also letting water vapour out of the building. Have a look on my channel, there are various videos where I discuss these issues when I built a garden room.

[@eleunameoiggam]

Great stuff. Would this method work with foil backed panels (e.g celotex pl400)? Thanks

[@AliDymock]

I don't know for sure, and that's partly why I went for the paper backed stuff. I've noticed that expanding foam doesn't stick at all well to foil but it may be a different story with this adhesive foam. Even with dot and dab, I've seen some people pva the foil first to get a stronger hold so that may be the work around. Test it and see!

[@mikeotoolephotography5829]

Great video well Done 😊

[@dooovde]

Nice job, but get ready to have mould start growing where you've used uncovered metal fixings at 11:49. The warm air will condense on the cold screw head and you'll have a lovely grey patch to keep wiping clean during the winter.

[@AliDymock]

Hmm I can’t imagine it would happen any more than on the windows but we’ll see. Have you got a link to fixings you would use?

[@reecebenton8634]

A good trick to not create a visible butt joint if you can’t fit a full board in a space, instead of fully cutting in half you can score the back side and snap the plasterboard, leaving the front paper intact. Works well with normal plasterboard, maybe some sealant in the back where the cut was in this one could work