Foam Board Insulation Under Roof

The foil insulation goes on top of the moisture barrier followed by the roof covering.

Foam board insulation under roof.

In warm climates zones 1 through 4 low density open cell spray foam insulation is the typical choice since it is vapor permeable and will allow drying of the exterior sheathing and roof framing if they happen to get wet via diffusion into the interior of the building. Although the r value isn t huge the rigid foam insulation boards do a nice job of keeping the searing heat of the roof from making its way into the sanctified space of the man cave. Closed cell polyisocyanurate foam core. Between the flat roof insulation and our install of reach radiant barrier insulation on our garage door the shop is now downright comfortable even in the warmer months.

Provides high r value per inch in built up modified bitumen metal roof and single ply roof systems and utilizes an environmentally compliant blowing agent that provides high thermal insulation performance. This foam board insulation is the rigid pink or blue panels that can be found at home centers in many different thicknesses. Rigid foam insulation also known as insulating boards provide high r values. It provides an r value of 4 per inch of thickness and is the cheapest type of foam board insulation.

If you use bubble foil or rigid foam insulation it also goes on top of the moisture barrier. Rigid insulation is one of the best tools to reduce your energy costs. You can even place it under the foundation slab. Polyurethane spray foam metal roof insulation in order to add moisture barrier under metal roof you can spray the undersides of the roof by using a thick layer of polyurethane spray foam.

Bare foam board one sided sheathing board or double sided which is also reference as structural insulated panels. Eps is used under roofing over foundation walls and beneath siding. Install it anywhere from the roof to the foundation. The article states that if some insulation is above sheathing foam board and some insulation is below something breathable then the insulation underneath should be attached directly to the roof sheathing.

Ul class a combustible wood deck approvals. It typically has 3 variations.