Insulating Flat Roof With Spray Foam

3 8 out of 5 stars 129.

Insulating flat roof with spray foam.

Such an insulating solution involves applying several layers of pur foam with each layer around 1 2 cm thick. Foam it green 602 closed cell spray foam insulation kit. Install composite insulation made from expanded polystyrene or eps foam laminated with a fiberglass facer that meets ul class a requirements. It is top quality and the most cost effective product for your flat roof.

Moisture generated indoors or that infiltrates into the home is responsible for the bulk of the moisture in an attic insulated with spray foam on the underside of the roof sheathing. You must meet the same minimum code requirements for the spray foam layer and the total assembly as for the rigid foam plus air permeable insulation approach. Holladay informed west that these options were discussed in a recent gba article insulating low slope residential roofs. While expensive the best insulation is polyiso rigid foam.

This means the insulation can be sprayed onto the underside of the flat roof to create a solid water resistant and pest resistant protection barrier. You can expect to pay about 55 100 sq ft. 5 0 out of 5 stars 3. Add some wood blocking at the roof edge for fascia to match insulation thickness and coat the spray foam and done.

Spray polyurethane roofing is still a thing its arguably the best insulation there is and you d install it right over the existing roll roofing. But spray foam insulation used at the underside of the roof deck would need to be covered by a thermal barrier and intumescent coatings are commonly used. A layer of spray polyurethane foam can be installed against the underside of the roof sheathing with the rest of the rafter cavity filled with air permeable insulation. For a 1 inch board equivalent of 6 r value.

Lstiburek takes blame for bad language. The effective roof insulation layer may range in thickness from 3 to 12 cm as needed. We recommend having at least 20 r value worth of material for optimal energy efficiency. Spray foam insulation is in a liquid form until it comes into contact with a surface where it begins to expand from its initial size up to a hundred times.

The movement of air into indirect conditioning of an unvented attic is a slow gradual process that will not be noticeable by occupants and typically will not put any strain on the hvac system. If the guy is worried about spray foam in the house then put it on the roof. 00 0 40 oz free shipping. Touch n seal high density spray foam roof insulation kit 3 0 pcf closed cell foam 120 bf.

It s not coming from above the roof and it s not some new moisture source resulting from the spray foam.