Internal Wall Insulation fixing (celotex GA 3000)

[engltayl]

I want to insulate the solid brick walls of my house, but I am confused about a few things and need some help.

I intend to use something like celotex GA 3000 (50mm) foil backed boards or the kingspan equivalent. Due to space i would like to apply these directly to the wall with minimal thickness.

What the best product to use to stick it to the brick walls (assuming i remove the old plaster). Drywall adhesive? no nails? something else?

I then want to fix the tapered plasterboard to the insulation. Can i bond it directly to the insulation or due i have to use drywall screws. I have read that you should back up any adhesive fixing with drywall screws.

If i use drywall screws do these have to fix into the insulation or do need to use some fixture into the brick behind the insulation.

I was orginally planning on using insulated plasterboard but these seem expensive in comparison. Am i correct in thinking a GA 3000 bonded to a plasterboard give pretty much the same product?

Thanks

 

[PrenticeBoyofDerry]

Right!
Your best method would be using a stud wall to insulate behind, then a vapour check barrier ie duplex foil backed boards.You can board out with standard boards and but a vapour barrier on prior to boarding. 12mm plasterboards are also recommended.
Tapered edged boards are really for joint taping rather than plastering.
So what application are you using to finish the wall in?
I can look for links later if you would like?

 

[noseall]

The most successful way (non mechanical) of fixing foil backed insulation boards, that we have used lately, is foam-fix.

As PBD has stated, you can batten a wall or fix a stud frame in front of the wall, either method will allow the mechanical fixing of the insulation boards.

But, if space is a premium, then a direct fixing can be achieved with foam.

 

[engltayl]

Thanks for your help.

 

[PrenticeBoyofDerry]

If your sticking them, I'd prefer thermaline boards, I can't see them being more expensive than Duplex and a Celotex/Kingspan system.
You may also need a second mechanical fix this can be achieved by using nailable plugs.
This a link to the batton out method: http://www.insulation.kingspan.com/uk/pdf/k18.pdf

 

[ajrobb]

I want to insulate the solid brick walls of my house, but I am confused about a few things and need some help.

I intend to use something like celotex GA 3000 (50mm) foil backed boards or the kingspan equivalent. Due to space i would like to apply these directly to the wall with minimal thickness.

I'd speak to the technical team of the board manufacturer. For instance, Kingspan K17 is commonly stuck directly to brick using dot and dab, but the manufacturer says 'except for exterior solid walls'. For exterior solid walls, I think they generally advise using Kingspan K18 on treated timber battens. There are low profile steel battens (e.g. from Gyproc).

With battens, you essentially get a cavity to allow penetrating damp to drain down the brick. You should remove the plaster as it will probably get damp. Given that the brick will be cold, it will no longer be dried out by heating. You should check your pointing as cold walls are more susceptible to frost damage.

I know you are asking about separate insulation boards, but I suspect the advice about battens would be similar. An advantage of separate insulation boards is that you can tape the joints on the warm side to complete the vapour barrier before covering with plasterboard. This allows you to be a bit approximate when butting the insulation boards together. You should probably join the plasterboard at the centre of the insulation boards.

If you do go down the route of sticking plasterboard to insulation stuck to the wall, you probably need some mechanical fixings too, in order to comply with building regs. A problem with brewing your own solution is that you cannot claim to be following the manufacturer's instructions. This might cause problems when you sell.