Urethane spray foam is an innovative insulating product that can be used to seal small gaps, weatherize crawl spaces and basements, or insulate entire houses. While large-scale application typically requires special tools, small spaces can be easily sprayed with cans available at most hardware stores. The foam is very sticky when wet but dries hard and can be easily cut with a drywall saw or a utility knife. Large areas can be trimmed with a reciprocating saw with a long blade.
Things You'll Need
- Drywall saw
- Reciprocating saw
- Long wood-cutting blade
- Utility knife
Trim small areas with a drywall saw. Use even strokes as you would on drywall or wood, cutting the material so that it is flush with the wooden framing enclosing it.
Trim larger areas with a reciprocating saw. Measure how far the foam extends beyond the framing and cut off that amount, being careful not to cut too deeply or remove so much that the insulation is too thin to do its job. Use a board that extends from stud-to-stud to help you gauge the amount you need to cut.
Use a utility knife to trim off small corners or areas you can't access with a saw. Use a knife to scrape off foam that may have dripped onto unwanted places.
Tips & Warnings
- If you inadvertently remove too much foam while cutting, simply spray on more foam, wait for it to dry, and cut again.
- While dry foam insulation is easy to manage, wet foam is another matter. Wet foam is extremely sticky and adheres to almost anything, including skin. It is very difficult to remove when wet and almost impossible when it has dried. Wear gloves and old clothes when working around spray foam and don't touch it until you are sure is is dry.
- Always wear protective goggles when working with saws. The use of gloves is recommended. Keep your hands away from moving saw blades.
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