One huge benefit of the spray foam insulated attic is that conditioned air leakage from the ac furnace duct system is contained and used to condition the attic.
Spray foam insulation attic only.
It has been said that insulating with spray foam insulation at the roof line will lead to moisture problems with the roof sheathing.
Polyurethane or polystyrene spray foams can provide thorough coverage to roof rafters and attic walls in much less time than is needed for other materials.
Nothing unusual about that.
The best part of using foam it green spray foam on an attic floor is you only need 1 inch cured thickness to seal the living spaces you use from the attic.
This application effectively seals off the attic from the outdoors and eliminates air leakage and infiltration through the attic and roof areas.
It really should be called spray foam insulation and air barrier.
Unvented attic assemblies unvented attics rely on an air impermeable insulation installed to the roof deck s underside i e.
Image courtesy of d7 spray foam insulation houston tx using spray foam insulation in an unvented attic application.
Once you deal with the air up there this problem goes away with or without the insulation in the attic floor.
A lot of builders and homeowners are going with spray foam insulation because of the airtightness benefits but then the questioner mentioned that the spray foam contractor had intentionally left big holes to the outside by not sealing the gable vents.
Open cell spray foam insulation can expand up to 100 times its original size to fill every nook and cranny in the cavity where it is applied.
To get a better air seal.
Earlier this year i got a question about a home that had spray foam insulation in the attic.
Only spray polyurethane foam can be used for this application as batt insulation will end up sagging and blown insulation simply can t adhere to the roof decking.
A properly done spray foam job not only insulates but also greatly reduces the air leakage of.
Spray foam insulation is an incomplete name.
When we seal the attic with spray foam it s as tight as a butter tub.
Spray foam insulation is an air barrier material that creates a seal against air movement.
Whereas too little spray foam insulation can leave for thermal bypass because of the complete lack of insulation in the attic.
Foam it green kits are portable and disposable and because they are low pressure the re entry time for the room being sprayed is only 1 hour.
Both low density open cell and medium density closed cell spray foam can be used in an unvented attic to provide the needed thermal resistance and airtightness.
Spray foam attic insulation pros and cons.
Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly.