1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Lining a room with Celotex/Kingspan

Discussion in 'Building Regulations and Planning Permission' started by wgt52, 16 May 2019.

  1. wgt52

    wgt52

    Joined:
    25 Apr 2016
    Messages:
    476
    Thanks Received:
    92
    Country:
    United Kingdom
    I'm considering lining the rooms in a solid walled house with PIR insulation. Is it a requirement that if I do that I have to install sprinkler systems (fire prevention) also?
     
  2. mrrusty

    mrrusty

    Joined:
    1 May 2018
    Messages:
    34
    Thanks Received:
    1
    Country:
    United Kingdom
    No. Easier to use insulation backed plasterboard. By building regs you can dot and dab fix it but technically need a couple of mechanical fixings to stop it dropping off the wall in a fire.

    Insulation backed PB has a vapour control barrier between the PB and the insulation. Your construction ends up similar to a timber framed house where the outer brick/stone becomes the outer skin.

    I asked my council BC officer about this because I'd heard that if you take all the original plaster off the wall you then have to bring the wall up to latest standards. He was not interested - he said in his view plaster was decoration so anything I did was better than original - he wasn't interested in minimum standards. We also discussed potential interstitial condensation if lining with insulated PB, and again he did not think it was a concern (I was lining out an edwardian house with a 2" cavity)
     
  3. ^woody^

    ^woody^

    Joined:
    3 Sep 2006
    Messages:
    26,073
    Thanks Received:
    3,203
    Location:
    West Mids
    Country:
    United Kingdom
    No. Why would you even think that?
     
  4. Notch7

    Notch7

    Joined:
    15 Sep 2017
    Messages:
    10,693
    Thanks Received:
    918
    Location:
    Sussex
    Country:
    United Kingdom
    Something to do with Grenfell I imagine.....
     
    • Like Like x 1
  5. jonbey

    jonbey

    Joined:
    17 May 2012
    Messages:
    2,560
    Thanks Received:
    125
    Country:
    United Kingdom
    Don't use insulation backed plasterboard, use kingspan + plasterboard.
    Much cheaper for the same amount / u-value of insulation, and easier to handle.

    I used loads of Everbuild Dry Fix to fix insulation to walls, then plasterboard to insulation - not moved yet. I also did my own test, sticking a strip of plasterboard to a but of wood, then tried to pull it off. Didn't budge.

    Here's one of the bedroom refurbs I did: https://photos.google.com/share/AF1...?key=dDkzRm83QWU4SVRGQ0N3aUhPaktjbmRseWM0OFV3

    This was the 2nd of 3. First was rough, last was amazing. Had a plasterer board the ceiling and skim the walls, but did the rest myself.
     
  6. mrrusty

    mrrusty

    Joined:
    1 May 2018
    Messages:
    34
    Thanks Received:
    1
    Country:
    United Kingdom
    You did a nice job, but I dispute the much cheaper. At my merchant 60mm PIR is £21, 12.5PB is £5.6, so £26.6. Add in another £3 or so for the second layer of foam fix and its close to £30. 72.5mm insulated PB (Siniat Xtratherm) is £37. (all +VAT). The insulated PB is dead flat and goes up like lego onto dabs, which is far more forgiving than foam on an uneven wall. The other advantage with using PB adhesive is it stays where its put once knocked in to place, whereas foam - even the proper adhesive type, will expand and push away if not held in place. Each to their own, but unless everything is flat and true, installing two different layers with foam adhesive to me seems more hassle than it's worth. Foam has it's place, and I've used loads, but it isn't a universal solution.
     
  7. jonbey

    jonbey

    Joined:
    17 May 2012
    Messages:
    2,560
    Thanks Received:
    125
    Country:
    United Kingdom
    £37 is a good price for that. I did order some from my local builder merchants, but it was very flimsy and low quality insulation (no idea of brand) so sent it back and went for separates. At the time, 30mm bonded to plasterboard was about the same price as 50mm kingspan + plasterboard. Prices probably changed since.
     
  8. noseall

    noseall

    Joined:
    2 Feb 2006
    Messages:
    34,070
    Thanks Received:
    2,142
    Location:
    Staffordshire
    Country:
    United Kingdom
    Not really, no.
     
  9. mrrusty

    mrrusty

    Joined:
    1 May 2018
    Messages:
    34
    Thanks Received:
    1
    Country:
    United Kingdom
    Having tried separate insulation + PB, battening out with insulation infill and insulated PB, which all produce similar outcomes, I know which I now prefer. Each to their own.
     
  10. ^woody^

    ^woody^

    Joined:
    3 Sep 2006
    Messages:
    26,073
    Thanks Received:
    3,203
    Location:
    West Mids
    Country:
    United Kingdom
    Where can somebody, who is not buying a container ship load of board, get 60mm insulated PB for £44? :cautious:
     
  11. mrrusty

    mrrusty

    Joined:
    1 May 2018
    Messages:
    34
    Thanks Received:
    1
    Country:
    United Kingdom

    Attached Files:

    Last edited: 17 May 2019
    • Thanks Thanks x 1
  12. noseall

    noseall

    Joined:
    2 Feb 2006
    Messages:
    34,070
    Thanks Received:
    2,142
    Location:
    Staffordshire
    Country:
    United Kingdom
    Absolutely - no.

    Separates means that vapour control can be introduced into each layer. It also means that the joints betwixt insulation and board (important) can be staggered. The two methods are like night and day.
     
  13. jonbey

    jonbey

    Joined:
    17 May 2012
    Messages:
    2,560
    Thanks Received:
    125
    Country:
    United Kingdom
    That reminds me, one of the reasons I decided to pay more for separates was for this reason - somebody here advised it. I was combating damp issues and didn't want water vapour getting past the plasterboard into the walls and elsewhere, so all insulation was sealed with tape before plasterboarding over. Some with the floor insulation.
     
  14. wwwebber

    wwwebber

    Joined:
    5 May 2004
    Messages:
    396
    Thanks Received:
    20
    Country:
    United Kingdom
    Used 50mm insulation backed PB on the inside of all external walls in my previous house. Had no issues in over 8 years.
     
  15. noseall

    noseall

    Joined:
    2 Feb 2006
    Messages:
    34,070
    Thanks Received:
    2,142
    Location:
    Staffordshire
    Country:
    United Kingdom
    That is likely. However, there are more robust ways of insulating whilst countering the problems associated with condensation, more effectively. Most people don't realise they have a condensation problem because they can't see it.
    Don't get me wrong, we still use dabbed pre-insulated boards where we have to. I prefer however to use separates where I can.
     
Loading...

Share This Page