Exterior Foam Roof Insulation

Adding exterior foam on an old roof is a good idea whenever a reroof is planned it is a once in 50 year opportunity to bring the house up to higher level of energy performance.

Exterior foam roof insulation.

The cavity insulation can be low density open cell or high density closed cell spray foam. Because old roofs were often framed with 2x6s there isn t much room for insulation. Dry in the roof with peel and stick membrane. First the foam will increase thermal performance by adding r value and minimizing thermal bridging.

Plywood or osb roof sheathing can be installed over exterior insulation layers using long exterior grade screws. An exterior foundation inside a basement against the foundation and on the outside of a house beneath a house wrap. In these assemblies the water control layer is typically the taped joints of the exterior rigid insulation. Install it anywhere from the roof to the foundation.

The benefits of adding a layer of rigid foam insulation to the exterior of walls and roofs are twofold. Foam board insulation is more expensive than. Owens corning foamular 150 1 in. R 5 scored square edge rigid foam board insulation sheathing model 20we view the owens corning exterior insulation 18 98 18 98.

Install two layers of insulation to the roof staggering the seams offsetting the joints and taping outer layer. Second the foam will keep the sheathing warm so moisture passing through the wall or roof will find no cold surfaces for condensation to occur. New roof sheathing on top can extend out to create a new roof overhang. On exterior spray foam roofing applications the roof sealing foam should be coated with a white roof coating after curing.

Insulation for condensation control table 1 adapted from table r 702 1 2018 international residential code roofs. Set your store to see local availability add to cart. When to use foam board insulation. The screws must be long enough to penetrate an adequate depth into the roof framing.

Buy 48 or more 15 18. An unvented roof cladding substrate e g. Spf roof patch spray foam is commonly used for sealing and insulating roof systems. Because of its resistance to moisture foam board insulation is a great choice whenever and wherever there is a chance it could get wet such as.

They keep your home at a comfortable temperature without the need to crank. Buy 48 or more 15 18. Rigid foam insulation also known as insulating boards provide high r values. View the owens corning exterior insulation 18 98 18 98.

Inviting exterior air into the center of your roof assembly between two layers of insulation has the effect of making your rigid foam worthless if you go this route you ll have to spend a lot of time conscientiously sealing up the air intake openings and air outlets for each ventilation channel whether at the soffit vents or at the.