Spray Insulation On Roof Deck

Design and construct a roof attic assembly with no vents.

Spray insulation on roof deck.

But foam also traps moisture in the roof in case of a leak. A sealed and insulated roof deck can t dry inward to the attic if the roofing happens to let water through. This though being the exterior will likely need more material to cover the entire roof which will likely require hiring professional installers. This measure will convert a vented attic to a nonvented attic.

Unvented roofs with spray foam applied to the underside of the roof deck have been used since the mid 1990s. Open cell spray polyurethane foam or closed cell spray polyurethane foam ccspf insulation can be sprayed along the underside of the roof sheathing to provide a conditioned and insulated attic space that can be durable and efficient in all climate zones see figure 1. The installation steps are as follows. Lstiburek takes blame for bad language.

It s not coming from above the roof and it s not some new moisture source resulting from the spray foam. Spray polyurethane foam or spf roof insulation is the best way to make your attic and entire home more comfortable and energy efficient. Insulate an attic in an existing home by installing spray foam open cell or closed cell on the underside of the roof deck. Applying closed cell spray insulation to the underside of a roof deck at the sheathing to truss connection can double or triple the strength of the assembly boosting the roof sheathing s resistance to wind uplift in a hurricane.

With the most affordable prices in the area our contractors can help you invest in your home. 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. As air impermeable insulation spray foam insulation can be used in such applications. For affordable insulation prices call 334 380 9550.

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. Water proof non breathing barriers can trap moisture on roof deck unless properly vented foam material when contacted with electrical wires can be dangerous rigid foam board is fairly expensive compared to other options. 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. In the northwest where foam has been sprayed directly to the underside of roof decks for over a decade the building officials interpret the code to require removal of existing insulation.

Inspect the existing roof shingles or roofing membrane for any deficiencies. The code allows for insulation directly to the underside of the structural roof sheathing providing the unvented attic is contained completely within the building thermal envelope.