Results 1 to 16 of 16

Thread: Spray foam insulation.

  1. #1
    Senior Member
    Join Date
    Feb 2013
    Location
    Glamorgan
    Posts
    1,914

    Spray foam insulation.

    Any long term applied results finding of the use in rooves and under slate applications?
    Pros ;were easy spray applied,insulation, stick all slates/bond to rafters etc etc, cons, seals all up, timbers rot quicker,u valves on too good as expected?
    Any veiws on the stuff?

  2. #2
    Senior Member
    Join Date
    Feb 2013
    Location
    M40 J15
    Posts
    327

    Re: Spray foam insulation.

    Birds will peck at it

  3. #3
    Senior Member Badshot's Avatar
    Join Date
    Feb 2013
    Location
    Kent
    Posts
    441

    Re: Spray foam insulation.

    Rats and mice LOVE it to live in.
    If in doubt get a bigger hammer

  4. #4
    Member
    Join Date
    Feb 2013
    Location
    Brimstone Hill, Cambridgeshire
    Posts
    34

    Re: Spray foam insulation.

    As above; mice, birds squirrels etc love it, if you have to repair your roof it's a pain, it's frightening how flamable it is if you manage to set light to it.

  5. #5
    Senior Member
    Join Date
    Feb 2013
    Location
    South Suffolk
    Posts
    367

    Re: Spray foam insulation.

    I have quite a lot of contact with architects and roofing contractors, and spraying foam to the underside of slated or tiled roofs seems to be the biggest single cause of major roof problems nowadays. In some circumstances it might work, but the risks are very serious, and personally I wouldn't even consider it. Spraying the back of corrugated iron in a steel framed shed is another matter, and the only cases I know of have worked very well.

  6. #6

    Re: Spray foam insulation.

    Don't do it, you don't want to seal the roof space up to make an air tight void

  7. #7
    Senior Member
    Join Date
    Feb 2013
    Location
    Shrops/Staffs/Cheshire borders
    Posts
    295

    Re: Spray foam insulation.

    Quote Originally Posted by RGT View Post
    Any long term applied results finding of the use in rooves and under slate applications?
    Pros ;were easy spray applied,insulation, stick all slates/bond to rafters etc etc, cons, seals all up, timbers rot quicker,u valves on too good as expected?
    Any veiws on the stuff?
    Are you talking domestic or agricultural?
    We did some above the milking parlour about ten (?) years ago. Apart from a few vermin and bird holes, it looks fine.
    I would guess that what folks above say about ventilation may be a problem in domestic situations, but I'm sure there are other ways of letting air in/out

  8. #8
    Senior Member
    Join Date
    Feb 2013
    Location
    South Suffolk
    Posts
    367

    Re: Spray foam insulation.

    The reduced ventilation is no worse than what would happen if the roof was re-felted and re-slated, and can easily be coped with.

    The real problem is that the roofing battens are encapsulated in a wet space between the slates and the foam, as are the slating nails. It's worse with old battens which are not preservative treated, but even new battens will not stand that for long, neither will the nails. Within a few years the whole roof covering is just sitting there more or less under its own weight, with no positive fixing. The foam holds it together well to start with, but it does deteriorate with time, and once the adhesion starts to go, and slates (or tiles) start coming off, there's not much alternative but to replace the whole roof, and the tiles or slates often aren't re-usable after foam either.

    There may be examples where foam is working extremely well, but I do know of quite a number of cases where the above has happened.

  9. #9
    Senior Member
    Join Date
    Feb 2013
    Location
    Glamorgan
    Posts
    1,914

    Re: Spray foam insulation.

    So if a tight dry roof, with no felt underneath, and you want to use the space, best to kingspan, tri-layer foil, and plasterboard best option?

  10. #10
    Senior Member
    Join Date
    Feb 2013
    Location
    M40 J15
    Posts
    327

    Re: Spray foam insulation.

    TLX silver/Trioso would be easiest IMO

  11. #11
    Senior Member
    Join Date
    Feb 2013
    Location
    Glamorgan
    Posts
    1,914

    Re: Spray foam insulation.

    Is that multi layer fabric type you staple up
    Rog?

  12. #12
    Senior Member
    Join Date
    Mar 2013
    Location
    Northumbrialand
    Posts
    1,257

    Re: Spray foam insulation.

    Can creep out under pan tiles, then expand and crack the tiles........
    gee

  13. #13
    Senior Member
    Join Date
    Feb 2013
    Location
    M40 J15
    Posts
    327

    Re: Spray foam insulation.

    Quote Originally Posted by RGT View Post
    Is that multi layer fabric type you staple up
    Rog?
    Yes that's the stuff, sometimes you also need a sheet/vapour barrier
    Google web dynamics & the answer will be there !

  14. #14
    Junior Member
    Join Date
    May 2017
    Location
    Dorset
    Posts
    6

    Re: Spray foam insulation.

    I have found some information that answers many objections about insulating with spray foam. It is not as straight forward as it seems, especially when insulating farm buildings.

    https://www.homelogic.co.uk/icynene-insulation-dangers/

  15. #15
    Junior Member
    Join Date
    May 2017
    Location
    Dorset
    Posts
    6

    Re: Spray foam insulation.

    Quote Originally Posted by RGSP View Post
    The reduced ventilation is no worse than what would happen if the roof was re-felted and re-slated, and can easily be coped with.

    The real problem is that the roofing battens are encapsulated in a wet space between the slates and the foam, as are the slating nails. It's worse with old battens which are not preservative treated, but even new battens will not stand that for long, neither will the nails. Within a few years the whole roof covering is just sitting there more or less under its own weight, with no positive fixing. The foam holds it together well to start with, but it does deteriorate with time, and once the adhesion starts to go, and slates (or tiles) start coming off, there's not much alternative but to replace the whole roof, and the tiles or slates often aren't re-usable after foam either.

    There may be examples where foam is working extremely well, but I do know of quite a number of cases where the above has happened.
    Those cases gone bad, would there be a possibility of a mistake from an installer or wrong type of foam used?

  16. #16
    Junior Member
    Join Date
    May 2017
    Location
    Dorset
    Posts
    6

    Re: Spray foam insulation.

    Many contrasting experiences with expandable foam insulation.
    I would never go with inexperienced installers who I know nothing about. I would search for some reviews also. The second thing would be the product itself. I guess to count out the risk of having a poor quality equivalent of foam sprayed in your property, it's best to speak to the contractor and get them to show you the certification and paperwork proving the use of original product.
    That's my idea anyway to avoid disappointment and costly repairs.

    Read for guide https://www.sprayfoamexperts.co.uk/s...ion-dangerous/

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •