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Spray Attic Insulation

  • 19-11-2021 11:05am
    Registered Users Posts: 2,716 ✭✭✭

    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: 384 ✭✭Biker1

  • Registered Users Posts: 384 ✭✭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.