Spray foam insulation is an insulating air barrier material that works by sealing the walls floors and ceiling cavities from airflow.
Foam sealed attic how to keep cool.
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.
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.
This foam can be placed around light fixtures electrical outlets windows and doors attics and crawl spaces.
Earlier this year i got a question about a home that had spray foam insulation in the attic.
Foam blocks airflow needs no vapor barrier and has a higher r value per inch than loose fill or batts so you ll get more protection with less depth.
When we seal the attic with spray foam it s as tight as a butter tub.
Attic fans push out the hot air and pull in the cool air from the vents installed on your roof.
With proper insulation at the roof it will capture the heat that is rising up from your heater and it won t leak outside through cracks high density spray foam is usually closed cell for this reason.
We mean that literally by the way.
They ve been well discussed here and other places but briefly they re not cost effective don t deal with the problem where it starts are using convection to solve a radiant heat problem and can even be dangerous by backdrafting combustion appliances and putting carbon monoxide in the home.
Adding an attic fan can improve the airflow in your attic to keep it cool.
As a result you can reduce the temperature in your attic by a lot anywhere from 120 degrees to around 95 during peak summer.
To ensure that the attic fan is working properly you need to make sure that your attic is sealed up tight where it touches the ceiling of the top floor.
Install 2 wide foam tape at least 1 4 thick on the attic side of the plywood at the edge and screw it to the ceiling centred over the opening.
When you insulate the top of your attic with spray foam you re bringing your attic into your home s envelope.
Then cover the foam with drywall as required for fire safety.
Nothing unusual about that.
Apply self adhesive foam weatherstrip tape to the top edge of the stop.
Then finish up by sealing the access hatch with self sticking foam weatherstrip photos 10 and 11.
3 screws each edge will compress the foam against the drywall and ensure an airtight fit.
Powered attic ventilators are the worst way to try to keep your attic cool.
When you re done sealing your attic bypasses push the insulation back into place with an old broom handle or stick as you back out of the attic.
However in a traditionally insulated attic insulation on the ceiling the attic is vented.
With spray foam unlike with loose fill or batts you must cover the soffit vents they aren t needed to keep the roof cool.
