Cut and insert 1 or thicker high r foam insulation sheets r 8 per inch against the furring giving a 1 or greater air path between the insulation and the roof deck under the cathedral ceiling.
Spray foam insulation under metal roof without air space good.
For best protection professional contractors recommend at least 6 inches of foam insulation board.
A roof breathes without spray on foam insulation to some extent and it also allows you to see where any dampness is coming in and repair it in this area.
The biggest benefit of spray foam insulation is its air sealing quality so if air is infiltrating into a spray foam attic then the installers missed some spots and need to go back and make it right.
Even small gaps can allow the passage of warm air through the foam rendering the foam all but useless as an insulator.
What s not guaranteed however is that all spray foam homes will be efficient and comfortable.
Nail 1 furring along every rafter side against the roof deck.
You take a shower but forget to turn the bath fan on.
You just need to make sure that you put in enough insulation to keep the sheathing above dew point temperature in the cold months.
Moisture from the house picture this.
They are not susceptible to moisture infiltration and will keep the roof dry even without a good ventilation system.
To get the best performance out of spray foam insulation you must cover the roof rafters and surrounding areas as thoroughly as possible.
In the knee wall area the insulation is in the floor and on the.
An unvented attic air sealed with spray foam insulation limits outdoor air entry and as a result indoor combustion air should not be considered available for fuel fired combustion appliances located within the attic space.