Roof Ventilation With Spray Foam

When installed over wood framing that has 28 to 35 per cent moisture content took approximately 35 days to dry less than 19 per cent moisture content compared to 8 5 days to dry with no foam attached.

Roof ventilation with spray foam. That means you get rid of all attic ventilation whether it s passive ridge gable soffit vents or active fans. That is now a conditioned part of your house just like any room in your house. Actually you should probably get rid of power attic ventilators whether or not you re sealing the attic but that s another article. Leave a gap on both sides.

This type of spray foam offers the specific benefits of continuous insulation interior wall cavity fill and unvented attic applications. In comparison to high density spray foam medium density spray foam is applied as a low or high pressure two component polyurethane spray foam. One of the biggest benefits of using spray foam is to get greater airtightness. These forms are only 1.

Spray the foam. Wood has an r value of about one per inch of thickness. If spray foam is used a vent space may still be needed directly under the roof deck. But with spray foam ventilation is not an issue.

This is not an issue specific to spray foam as much as it is a characteristic of peel and stick membranes. Mark bomber s book spray polyurethane foam in external envelopes of buildings reports on research that demonstrates ccspf under typical building conditions i e. Temporarily secure long plastic forms between the rafters on the inside of the ceiling. How to vent a foam insulated roof step 1.

It also reported the air sealing qualities of the foam were retained. Build the rafters and secure the 5 8 inch cdx sheathing material.