PIR boards

[Richhen]

Hi all,

DIY'er looking for some advice.....
After some kitchen alterations, I have an external brick wall 2.4m x 2.4m which I need to insulate and plaster.
My building warrant plans specify Celotex PL4050 which is a PIR board with 50mm insulation and 12.5mm plasterboard combined as one sheet.
Turns out there is a nationwide shortage of PIR board and deliveries are approx 4 weeks at earliest - I can't wait this long!
As a diy'er new to this, I'm keen on the combined insulation/plasterboard as it seems easier.
Do I need to use PIR board? How does this differ from standard insulated plasterboard? It's a small wall so could I get away with out the PIR or is there something else I can do to the wall to compensate for not using PIR board?
Many thanks for your advice!

Rich

 

[B17NNS]

Can you not find an alternative board with an equivalent uValue?

 

[Richhen]

Can you not find an alternative board with an equivalent uValue?

I can get the insulation board, but without the plasterboard attached. I assume I can stick the insulation board to the wall with adhesive and then stick the plasterboard to that. Seems simple enough - almost too simple! - am I missing something???

 

[DIYedboy]

Be careful...............if the board is aluminium faced, the only thing that will stick it long term is foam adhesive (the minimal expanding type), you'll then have to foam the plasterboard to that.

 

[Richhen]

Be careful...............if the board is aluminium faced, the only thing that will stick it long term is foam adhesive (the minimal expanding type), you'll then have to foam the plasterboard to that.

Ah, that's a good tip, thanks
Would it be better and more proper to stick the insulation board to the wall, then batton the front of the insulation, then screw the plasterboard to the batons, or perhaps the stick together approach (with the correct foam of course) will be adequate. It's only a small wall 2.4m x 2.4m. Thanks

 

[DIYedboy]

If it was me, I'd foam the celotex to the p/b then foam the combined unit to the wall, remember you are also supposed to bung in at least 3 mechanical fixings per board in order to comply with fire regs (if there's a fire the boards may fall off the wall and block an exit route)

 

[Richhen]

Thanks DIYedboy, that's great advice and exactly why these forums are so helpful.