Spray Foam Roofing - The Basics

Spray Polyurethane Foam Roofing is sprayed as a liquid that then expands into foam. The foam then creates a solid layer on the surface of a roof deck or wall. The actual material that is Spray Polyurethane Foam is produced on the job site by mixing two highly reactive chemicals. The chemicals are polyol/resin and isocyanate, these two chemicals are pumped through heated pressure hoses to an enclosed spray gun. What then comes out of the spray gun is the liquid that expands into foam.

Polyurethane is a foam insulation material that contains a low-conductivity gas in its cells. Polyurethane foam insulation is available in closed-cell and open-cell formulas. With closed-cell foam, the high-density cells are closed and filled with a gas that helps the foam expand to fill the spaces around it. Open-cell foam cells are not as dense and are filled with air, which gives the insulation a spongy texture and a lower R-value.

An R-value is an insulating material's resistance to conductive heat flow. The higher the R-value, the greater the insulating effectiveness. The R-value depends on the type of insulation, thickness, and density.

Spray foam has one of the highest R-values of other roof insulation systems used.

Open cell spray foam insulation is R-3.6 to R-3.9 per inch.

Closed cell spray foam insulation is R-6 to R-7 per inch. 

Sprayed or foamed-in-place applications of polyurethane insulation are usually cheaper than installing foam boards, and these applications usually perform better because the liquid foam molds itself to all of the surfaces. All closed-cell polyurethane foam insulation made today is produced with a non-HCFC (hydrochlorofluorocarbon) gas as the foaming agent.

Low-density, open-cell polyurethane foams use air as the blowing agent and have an R-value that doesn't change over time. These foams are similar to conventional polyurethane foams, but are more flexible. Some low-density varieties use carbon dioxide (CO2) as the foaming agent.

Low-density foams are sprayed into open wall cavities and rapidly expand to seal and fill the cavity. Slow expanding foam is also available, which is intended for cavities in existing homes. The liquid foam expands very slowly, reducing the chance of damaging the wall from over expansion. The foam is water vapor permeable, remains flexible, and is resistant to wicking of moisture. It provides good air sealing and is fire resistant and won't sustain a flame.

Spray foam doesn't just block heat flow, it also stops airflow, which keeps your business comfortable all while reducing your energy bills.

Spray foam creates an air seal that keeps the air moving freely into and out of your business.

Spray foam is a premium insulation material.