If you have a new account but are having problems posting or verifying your account, please email us on [email protected] for help. Thanks :)
Private profiles - please note that profiles marked as private will soon be public. This will facilitate moderation so mods can view users' warning histories. All of your posts across the site will appear on your profile page (including PI, RI). Groups posts will remain private except to users who have access to the same Groups as you. Thread here
Some important site news, please read here. Thanks!

Spray Attic Insulation

  • 19-11-2021 10:05am
    Registered Users Posts: 2,690 ✭✭✭ brightkane

    Hi Folks,

    Looking for some advice please.

    Neighbours of ours have had their attic sprayed with insulation on the underside of the roof and its a great job for comfort in their house.

    We had 2 companies out to quote for the same job, Similar price.

    Company 1 - Spray directly onto the felt, its "breathable" so no change of rot but will be an air tight seal

    Company 2 - Put a card to between the eaves and spray onto that leaving air to play behind it but not penetrate the attic. Leaving attic air tight.

    Any idea which is best? I have read some stories about rotting wood ect and having to tear it out for selling the house so was wondering if anyone else was in the same boat as me, got it done and what did they go for?



  • Registered Users Posts: 255 ✭✭ Biker1

  • Registered Users Posts: 255 ✭✭ Biker1

    Neither scenario is a runner. Cannot spray directly onto felt. 50mm ventilation space required between insulation and felt. Second option is idiotic. Again your roof space requires ventilation to prevent timbers rotting.