Insulating Flat Roof With Spray Foam

Lstiburek takes blame for bad language.

Insulating flat roof with spray foam.

While expensive the best insulation is polyiso rigid foam. 00 0 40 oz free shipping. 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. Install composite insulation made from expanded polystyrene or eps foam laminated with a fiberglass facer that meets ul class a requirements.

Composite insulation works in flat and low sloped. Closed cell polyurethane spray foam will prove ideal for thermal insulation of a flat roof. 5 0 out of 5 stars 3. 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.

It is top quality and the most cost effective product for your flat roof. If the guy is worried about spray foam in the house then put it on the roof. What s left he adds are using spray foam insulation on the underside of the roof sheathing or rigid foam on top of the roof sheathing. 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 can expect to pay about 55 100 sq ft. 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. 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. We recommend having at least 20 r value worth of material for optimal energy efficiency.

Foam it green 602 closed cell spray foam insulation kit. 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. It s not coming from above the roof and it s not some new moisture source resulting from the spray foam. The effective roof insulation layer may range in thickness from 3 to 12 cm as needed.

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. 3 8 out of 5 stars 129. Touch n seal high density spray foam roof insulation kit 3 0 pcf closed cell foam 120 bf. Holladay informed west that these options were discussed in a recent gba article insulating low slope residential roofs.

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.