Spray Foam Under Roof Sheeting

The problem with using.

Spray foam under roof sheeting. Spray foam on underside of roof sheathing. Wood has an r value of about one per inch of thickness. There have been isolated moisture related incidents that raise potential concerns about the overall hygrothermal performance of these systems. Spray foaming under roof sheathing ive heard a lot of good things about spray foaming underneath the roof sheathing.

It rots roofs people have told me. Underside of roof decks since the late 60s early 70s and to my knowledge i have not seen or heard of a rotted substrate under and conditions closed cell foam was applied. We ll add a vapor barrier so the moist air does not flow up through the insulation and condense on the roof. Inspecting spray foam insulation applied under plywood and osb roof sheathing by ben gromicko and nick gromicko cmi because most heat loss in a home is through the attic increasing attic insulation is one of the most cost effective steps homeowners can take to improve their home s energy efficiency.

If spray foam is used a vent space may still be needed directly under the roof deck. Murmurs and hearsay about open cell spray foam insulation have been gaining traction for a while. While covering a given area with spray foam costs more initially than the equivalent amount of mineral wool batting or other insulating materials its ability to fill even tiny spaces completely enables it to provide greater thermal resistance leading to greater energy efficiency and. Polyurethane spray foam metal roof insulation in order to add moisture barrier under metal roof you can spray the undersides of the roof by using a thick layer of polyurethane spray foam.

If anyone has please contact me with evidence that being said open cell is a great product as well however in your case you. Not long ago someone even told me that in florida roofing companies won t let their workers go up on roofs with open cell spray foam because the roofs are so spongy the guys fall right through. Unvented roof strategies with open cell and closed cell spray polyurethane foam insulation sprayed to the underside of roof sheathing have been used since the mid 1990 s to provide durable and efficient building enclosures. Our house was built in 1904 and the square footage of the attic floor is about 1100.

But a preinstalled membrane may be even more effective at removing condensation. This is not an issue specific to spray foam as much as it is a characteristic of peel and stick membranes. Allowing foam directly to the underside of. Traditionally we ve insulated the roof panel to try and keep the temperature on the panel from reaching the dew point.