Insulating Vaulted Ceiling Rigid Foam

The higher r value reduces condensation when moist interior air hits the now less cold ceiling vice versa in summer with humid outside air.

Insulating vaulted ceiling rigid foam.

About the only time you are likely to add rigid insulation to a ceiling is in a retrofit of a cathedral ceiling. Insulating a vaulted ceiling is similar to insulating exterior walls with one notable difference. Spray foam closed cell is way out of our budget. A less expensive alternative is the more traditional vented cathedral ceiling insulated with fiberglass cellulose or open cell foam.

This is best for simple cathedral ceilings that are easy to ventilate. Foam board insulation would be a more economical especially if you are supplying the labor see photo. Closed cell foam ceiling insulation in a vaulted ceiling offers substantial advantages over open cell. Vaulted ceilings require venting as well as insulation.

In most cases however insulation will not help prevent moisture. Attics and cathedral vaulted ceilings. Putting an addition on cathedral ceiling pitch is 12 12 with 2 10 rafters. The roof starts with scissor trusses set on 8 foot centers.

These should have straightforward framing with no skylights and with direct access to soffit and ridge vents. He wants a trouble free roof assembly but local advice on insulation and air sealing has been hard to find. R value insulation receives a rating. Kevin is working up the design for a new lakeside cabin in tennessee with plans currently calling for a scissor truss roof and a vaulted ceiling over the kitchen and living area.

The rigid foam layers are installed with staggered seams. Johns manville aptm foil faced insulation sheathing board is an excellent choice for insulating attics and cathedral vaulted ceilings. Polyiso provides one of the highest r values per inch of any rigid insulation r 6 at 1 inch. Advantages of rigid foam insulation under the roof.

Foil faced iso board can be cost effective insulation for finished attics and cathedral ceilings. Regular ceilings are likely to be under. Vented ceiling across rafters. How to attach rigid insulation to ceilings.

First closed cell foam has a 60 percent higher r value per inch than open cell 6 3 vs. Spray foam is a very expensive option however.