Nothing unusual about that.
Attic closed cell foam under blown insulation.
But it s harder and the chances of success are lower.
The foam usually polyurethane is sprayed to fill cracks and gaps in the attic to form a hermetically sealed barrier.
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.
Spray foam provides the highest r value while open cell spray foam has about an r value of 2 2 to 3 5 per inch closed cell spray foam has about 6 7 per inch.
Earlier this year i got a question about a home that had spray foam insulation in the attic.
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.
However in a traditionally insulated attic insulation on the ceiling the attic is vented.
Whereas blown in insulation works by filling the.
This type of spray foam offers the specific benefits of continuous insulation interior wall cavity fill and unvented attic applications.
Closed cell foams use enovate also known as 245fa which is.
If you leave the existing insulation in the attic it interferes with the foam installation.
In an attic the eaves are one of the most critical places to get good coverage with the foam.
Open and closed cell foam insulation use a blowing agent to forms the cells within it.
When we seal the attic with spray foam it s as tight as a butter tub.
This medium density spray foam is a closed cell spray foam that is typically used where there is the need for r value insulation per inch possible.
How ducts in an unvented attic should be installed.
Medium density closed cell spray foam ccspf.
Open or closed cell spray foam is applied to the underside of the roof sheathing and additional fiberglass or cellulose insulation is blown in as a cost saving method for meeting high insulation requirements and filling in the cavity space between the rafters to the ceiling deck.
Yeah if you do a really good job raking the insulation back you can still do a good job with the foam.
Because it requires professional installation closed cell foam insulation is pricey but it offers r 6 thermal value for every inch of thickness.
Typically this foam s natural color is yellow when applied in insulation.
