Thermal Insulation Wall Boards

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Hi,

After years of suffering from a very cold hallway (late 20s end of terrace solid walls) we are going to take the plunge and fit some internal insulated wall boards.

Unfortunately we do have space issues - the stairs are quite narrow as it is - and will only have about 40mm max to play with. I have looked at GTEC Thermal XP and Knauf XPS wall boards. Both are 35mm thick of which 9mm is the plasterbaord. I know in an ideal world we would fit 100mm thick boards but this is just not possible.

I am intending to mechanically fix these to the wall and then paper over with thick lining paper.

Are all of these type wallboards pretty much as good as each other? Do people think wallboards of this thickness will make any differnce at all?

Thanks
 
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The thicker the better, can you strip the plaster first then you can add another 12mm to the thickness.

Yes you will feel the difference, a foam backed board is more efficient than a polystyrene backed one. Use tapered edge board then you can flare joins n you shouldn't need lining paper
 
Thanks DIYedboy.

I did consider taking off the old plaster. However I know somebody up the road who tried the same thing and it was very very heavy going. The original plaster was more like concrete and it was not easy getting a flatish surface.

Rightly or wrongly I am just hoping that a 35mm insulated plaster board will be thick enough to make a difference.

I was going to use thickish lining paper rather than a re skim because I assume it will leave a slighter warmer feel to the hall (and be cheaper).
 
I have a 1930's house, the internal plaster is RENDER,it is rock hard and a hammer and bolster just bounce off it BUT it comes off really easily with a £70 demolition hammer drill from screwfix.

the lining paper will not help thermal insulation at all
 
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Thanks DIYedboy

You're probably right. Although part of me just wants to get on with it and use the 35mm wallboards I suppose I should start to take some of the original plaster off and see how I go.

It's probably the sensible thing to do.
 
Tricky decision eh!

Just think of all that mess, loads of trips to the tip, dust everywhere, collateral damage to adjacent walls, ceiling...

Or just accept that's what's required for a proper job. You might end up being able to use 40mm insulation with 9mm plasterboard.

Interested in how you would fix the boards to the wall? How many fixings?
 
You are quite right Reg. It was a tricky decision!

We are going to write off this winter, wait a few months then get it done in Spring. I've got a couple of helpers so hope to get the old plaster stripped in a day.

Haven't decided which insulation board to go with yet but hope to get something around 40-45mm thick in total. Will report back when it's all done.

DIYedboy - which £70 demolition hammer are you referring to in Screwfix? I was hoping to get away with the Titan SDS plus drill with a tile chisel. Currently £49.99 in Screwfix.

Thanks
 
Just for the record.....

Stripped of the old plaster at the weekend. Myself plus two helpers. We was all set up for a long day. But the wall was stripped by lunchtime! So pleased we took the plunge. We used two old SDS drills plus I bought the £49 Titan SDS 5kg drill from Screwfix which was excellent. Definitely added 15mm to the space I have available. The original plaster looked more like concrete to me but it did come off reasonably easily.

Only slight downside (although less for me than the mrs) was the mess. We covered all the doors off the hall but the dust got absolutely everywhere - took the whole of sunday to clean it all up. Well worth it though.

Probably going to go with Gyproc therlamaline plus 40mm (9mm plasterboard/31mm insulation). This won't take too much space off the stairs which are narrow as it is. Also opting for mechanical fixing. Assume I have to go with special fixings? Or do people think dot and dab would be easier/more effective. Will finish off with getting somebody to skim it.

I covered the wall with some PVA to stop the dust coming off. Should I use any other sealant before fixing the plasterboard? Any other pitfalls I should be aware of?

Grateful for any advice. Thanks.
 
Dear Monty,
Sorry that this is bit of a question (or a warning) rather than a solution.

Great to hear that you are using insulated plasterboard, it will made a difference.

However I am worried about your attachment method. If it is metal screws or framing screws will it cause bridging of the cold from your wall to your plasterboard. I know this will be small, but this might cause circles of cold plaster where its cold and moisture/damp might collect?

So again, sorry that this is a question, but I am interested as this is something I need to do in the future, and so am interested in your experiences and solutions.

SFK
 
Thanks for your comments SFK.

Good point about the metal screws. It wasn't something I had really thought about. Just checked out how costly they are too. Seem to be almost a pound each! Unless I am looking at the wrong things. My helper is in charge for this operation so if he really wants to stick with mechanical fixing then I will go along with it.

How easy is dot and dab? More difficult than mechanical fixing?
 
Dear Monty,
As a DIYer Always been too scared to use dot an dab as worried that each plater sheet would be out of alignment with next and that plasterer would (correctly) scream at me. And that I would not get enough dots, dots would not affix to my dusty bricks, etc, etc. But this is my inexperience talking as my understanding is that this is the "proper way" to do it.

Another way is to affix wood straps onto brick wall at 40cm or 60cm centers. Use shims to get these flat to each other. And then use long plasterboard screws to screw plasterboard onto wood. I presume that the wood reduces the bridging effect. But it puts the price up as you can put 25mm celotex between the 25mm thick wood straps, and then put thermal plasterboard on top (so shims+25mm+25mm+12mm=>62mm thick.

Frame Screws seem to have a wild range of prices, as you say some start at £1 each!! However in bulk they are cheaper when I did a screwfix search of "Frame Screws":
http://www.screwfix.com/p/rawlplug-pa6-nylon-frame-fixings-8-x-100mm-pack-of-50/20795

SFK
 
Just for the record.....

We put up the 40mm Gyproc Thermaline Plus plasterboard at the weekend. We used the dot and dab method. It went really well and was a lot easier than we thought it was going to be. We added a couple of hammer fixings on each board for good measure. The adhesive - Gyproc Dri Wall Adhesive was good stuff. It really sticks on solid. One word of warning though. I mixed it up on our front drive and did make a bit of a mess. Assumed I could just clear up the residue with a jet washer. Wrong. Got some of it off but still doesn't look good.

Now just got to get it skimmed.

One question re the skimming. We have a few gaps between some of the boards. Should I fill and tape them first or do you think I should leave that to the plasterer?
 
Dear Monty,
Always great to hear feedback as means that I can now have a try :>

Regarding 'tape' I (as a DIYer) would leave that to the plasterer as I guess he will have a preferred method / tape and also then it is his issue, not yours, if it comes off.


Note that my plasterer used flat tape (not the one with holes in) so his plaster would not have been able to fill the gaps in the manner I think you are hoping for. So (for my own piece of mind and sometimes because I left gaps that were wider than I wanted to show to a plasterer) I filled the gaps with a bead of cheap version NoMoreNails. The plasterer then taped and skimmed with no comments (that I heard :> ).

SFK




ne question re the skimming. We have a few gaps between some of the boards. Should I fill and tape them first or do you think I should leave that to the plasterer?

Read more: //www.diynot.com/diy/threads/thermal-insulation-wall-boards.424957/#3364374#ixzz3XGqqNj43
 

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