Rigid Foam Insulation Roof Installation

A helpful hint for installation is to use a straight edge along the cut line to ensure the panels fit best.

Rigid foam insulation roof installation.

Apply continuous air control membrane to existing roof sheathing or implement continuous air control at roof sheathing. To install measure the foam insulation panels to the roof s dimensions. Polyiso is an easy cost effective sustainable and energy efficient construction material. Keep foam board insulation away from direct sunlight prior to installation.

Remove existing roofing and non adhered underlayment to expose roof sheathing. If you want to install rigid foam above your roof sheathing in climate zone 3 then 1 2 inch of rigid foam board is not ideal this rigid foam layer needs a minimum r value of r 5 and that s impossible with 1 2 inch of foam. Install rigid insulation board in multiple layers with joints offset vertically and horizontally between adjacent layers. All foam boards absorb water vapor.

Nail metal flashing along the edges of the. Use a straight edge knife or utility knife to cut the panels to size. Rigid insulation is one of the best tools to reduce your energy costs. Johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency.

Rigid foam insulation also known as insulating boards provide high r values. Install 1 by 3 furring strips over the insulation panels on top of each stud. R panel is manufactured with a closed cell polyisocyanurate foam core bonded to fiberglass reinforced facers and designed for use over metal nailable and non nailable roof decks with a variety of membrane systems. Rigid foam offers tremendous boost to a home or office s r value.

Cover the insulation with a vapor barrier before you install it. Unroll roofing felt to cover the plywood on the roof and nail it in place. One of the best benefits of rigid foam insulation is that it offers excellent thermal resistance at around double that of traditional insulation. When installing the foam use caulk or tape for maximum insulation between the material and the board or floor.

You can even place it under the foundation slab. All three types of rigid foam insulation expanded polystyrene eps extruded polystyrene xps and polyisocyanurate are suitable for use on the exterior of walls and roofs though they do not perform equally. How to put rigid foam insulation on the roof before putting on shingles 1. It will degrade its r value.

As my article states you need a minimum of about 1 5 inch of eps 1 inch of xps or 1 inch of polyiso. Eps is the most vapor permeable of the three types. At r 4 it also has the lowest r value per inch. They keep your home at a comfortable temperature without the need to crank your heat.

Install it anywhere from the roof to the foundation. The ideal roof there s a reason polyiso rigid foam insulation is used in more than 70 of commercial roof construction as well as in many residential builds.