How to Use Expanding Foam Insulation

  • 4-12 hours
  • Beginner
  • 250-750
What You'll Need
Several rolls of masking tape
Plastic sheets
Spray foam insulation kit or cans (depending on amount of area to be insulated)
Safety glasses (heavily recommended)
Gloves (heavily recommended)
Respirator mask (heavily recommended)
Long sleeve and long pant clothing
Carpet razor knife

The use of expanding foam insulation will provide for excellent insulation within walls, ceilings or below flooring. This superior product may be slightly more expensive than fiberglass or loose-fill, cellulose products, but its longevity will more than compensate for its extra cost. It is very easy to use, is fast acting and will provide very thorough insulation value. If used correctly, this expanding foam insulation will more than adequately fill cracks, spaces and voids within walls, ceilings or under flooring.

Step 1 - Wear Protective Clothing

It is essential that work is not begun without wearing protective clothing. Wear long pants, a long sleeved shirt and a hat. Use protective eye wear as well as a certified and adequate respirator face mask. Use a good pair of rubberized but flexible gloves to handle all materials. Mask off all areas, especially electrical equipment, cover windows and all items that should be protected from the spray foam insulation. Use plastic sheets for larger areas to be covered.

Not to put too fine a point on safety, but it is well worth knowing that working with spray foam can cause itching and redness of the skin. This allergic reaction can be limited by wearing safety equipment and clothing as well as showering immediately upon completion of the spraying of foam insulation.

It is essential that a respirator be worn at all times as spraying foam insulation can cause major medical respiratory problems as well as temporary blindness.

Step 2 - Read Instructions Carefully

Be certain to follow the manufacturer’s instructions carefully and familiarize yourself thoroughly with the process of using spray foam insulation before beginning any application. Allow enough time and materials to complete each section required to be insulated. Essentially, prep, apply insulation and cleanup each section of the insulation process.

Step 3 - Begin Insulation Procedure

Position the expanding foam insulation applicator approximately 20 inches from the area to which it is being applied. Begin with a conservative 1 inch bead of insulation around the surrounding area and the wall’s 2x4s. Begin with either an up and down, or side to side motion to carefully apply the foam insulation in a uniform manner. Applications of expanding foam insulation should be conservative, allowing drying time between each application to ensure adequate coverage has been applied. Less is better in this instance.

When the foam insulation has dried, inspect the areas for complete coverage and voids. Fill in the voids as needed, and move on if coverage is adequate. Do not apply any more foam insulation than is needed.

Trim excess foam insulation with the carpet razor knife and clean up the area as best as possible. The key here is to not have any insulation protruding so as to limit the installation of dry wall or sheet rock. Aim for a flush fitting wall of insulation that looks good and will accommodate applications of other building materials.