Spray Foam Insulation Attic Only

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.

This application effectively seals off the attic from the outdoors and eliminates air leakage and infiltration through the attic and roof areas. 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. When we seal the attic with spray foam it s as tight as a butter tub. It has been said that insulating with spray foam insulation at the roof line will lead to moisture problems with the roof sheathing.

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. However in a traditionally insulated attic insulation on the ceiling the attic is vented. Unvented attic assemblies unvented attics rely on an air impermeable insulation installed to the roof deck s underside i e. To get a better air seal.

Whereas too little spray foam insulation can leave for thermal bypass because of the complete lack of insulation in the attic. Attic ceiling to stop airborne moisture from reaching a cold surface and condensing inside the building envelope in this design insulation effectively separates the interior and exterior spaces while slowing down moisture flow so the dewpoint is not achieved within. Spray foam attic insulation pros and cons. 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 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. Image courtesy of d7 spray foam insulation houston tx using spray foam insulation in an unvented attic application. 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. It really should be called spray foam insulation and air barrier.

Spray foam insulation is an incomplete name. Spray foam insulation is an air barrier material that creates a seal against air movement. 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. Nothing unusual about that.

Moisture is also another huge issue when it comes to spray foam insulation in an attic. Earlier this year i got a question about a home that had spray foam insulation in the attic. 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.