How Does Foam Insulation Work on Windows?

Foam Insulation

• When spray polyurethane foam, or SPF, an insulating and sealing material, is sprayed into a gap, it expands to fit the area completely. The foam hardens to create a solid insulating barrier in the space. Professionals often use a two-part high-pressure foam that combines and reacts in the nozzle just before spraying. SPF for do-it-yourself homeowners is sold in cans with the components already reacted for easier installation.

Insulation Type for Windows

• Due to the nature of the window frame, windows require low-pressure spray foam insulation. High-pressure foam is likely to expand too much and press against the window frame, possibly causing bowing that affects the opening and closing of the window. Specialty products designed for doors and windows are the best option for avoiding any damage to the area.

Use and Application

• The expanding foam insulation is used in the gaps surrounding the window frame. To use the foam, you'll need to remove the window trim. The user sprays the foam insulation into the gap between the window jamb and the wall. The foam fills this area to insulate and seal the gaps around the windows. The air is not able to get through this area once the foam insulation is in place.

Safety

• The spray foam insulation contains potentially dangerous chemicals that help it spray and expand into the window frame gaps. Individuals with asthma, respiratory problems or allergies are particularly susceptible. Covering the skin with long clothes and gloves reduces exposure to the chemicals. Eye protection is also essential during the application. Limit inhaling the fumes from the spray foam for additional protection and reduction in complications. If the spray foam is cut or sanded, a facemask reduces the risk of inhaling dust from the foam.