Spray Foam Insulation?

Discussion in 'Builders' Talk' started by BlueberryMuffin, Mar 12, 2018.

  1. BlueberryMuffin

    BlueberryMuffin New Member

    Hello All. New to this forum but have a burning question on insulation. So the house has plasterboarded vaulted ceilings all round. I cannot confirm that there is any insulation at all in the shallow areas between the the ceiling slope and the roof exterior. I have notice though that the bedrooms are freezing. The question is, is spraying foam insulator in these areas the way forward and will i then need to add more ventilation to the loft? Your thoughts please.
     
  2. KIAB

    KIAB Well-Known Member

    No to foam, better to strip back, use a insulation batt between the joists,then use a insulated plaster board.

    Even just overboarding with a insulated plasterboard you should see a difference,but above method is better.
     
  3. Jord86

    Jord86 Well-Known Member

    Spray foam, no. Cutting and fitting 3inch celotex/kingspan between the vaulted part and between the ceiling joists, yes.
     
    KIAB likes this.
  4. BlueberryMuffin

    BlueberryMuffin New Member

    Thanks for the replies. Whats the reason for the big no to foam?
     
  5. KIAB

    KIAB Well-Known Member

    We agree.:eek::D
     
  6. KIAB

    KIAB Well-Known Member

    You don't know where it's going, & you don't know if you'll fill all the void,& expanding foam could cause other problems with expansion.
     
  7. BlueberryMuffin

    BlueberryMuffin New Member

    Fair point, thanks
     
  8. Jord86

    Jord86 Well-Known Member

    You need ventilation within a roof otherwise you'll develop condensation, damp, rot issues, etc. There is an argument for open cell/closed cell spray foam, but it's not common over here, more in the U.S.
     
    KIAB likes this.
  9. Jord86

    Jord86 Well-Known Member

    Don't be so surprised, I'm a fellow advocate of foam, just not in this situation :)
     
    KIAB likes this.
  10. KIAB

    KIAB Well-Known Member

    Me too, in the right location.:)
     
    Jord86 likes this.
  11. Jord86

    Jord86 Well-Known Member

    Like behind a backbox. :D
     
  12. KIAB

    KIAB Well-Known Member

    :eek:

    Careful, you get Dobbie all worked up...:rolleyes::D
     
    Dr Bodgit, chippie244 and Jord86 like this.
  13. Bob Rathbone

    Bob Rathbone Well-Known Member

    If their is no underfelt, the foam will ensure any loose tiles are fixed, it will prevent the ingress of snow. BUT it will give off a hazardous gas during curing and for some time afterwards, the main component of the foam is Toluene, very toxic and has the ability to sensitize those affected by it so that in future, only a small exposure will be needed to trigger a reaction. How do I know? I worked with this stuff in a factory environment when I was a maintenance spark.
    If the roof is good, strip off the existing plaster and lath and fit hard insulation between the joists, sealing the joins and gaps. A vapour barrier over then board and skim as required. Insulation backed board is very expensive. Perhaps re wire the lighting circuit also.
     
  14. dobbie

    dobbie Well-Known Member

    Nothing wrong with a bit of banter with people like yourself Jord,who are or have been on the tools.
    It is different when it comes from someone who can only post Lots of links, pictures and comments that have been found by searching on google, you need hands on experience from the real world like yourself, myself and other people working in the game actually have.

    There are also many very good diy people on here who post comments and advice and lot of it is good and helpfull advice.

    It brings the credibility of the forum down though when someone we all know, claims to have done things bigger and better than previous posters,(without practical experience) has had the same the thing happen to them or a friend,but in a more spectacular fashion,parrots and agrees with some posters and always has some excuse that no one believes when he is wrong.

    Post by all means, but admit the truth that it was always your dream to work in the building trade,you have no practical experience whatever and any advice you give has been gleaned from this and other diy/trade forums,not actual work.
     
  15. chippie244

    chippie244 Well-Known Member

    Do you mean anyone in particular Dobs?
     

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