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How to Use Expanding Foam Spray Cans

Expanding spray foam is one of the fastest and easiest ways to seal around doors and windows, in gaps in masonry or in any hard to reach place that only needs a little insulation.

Things You Will Need

  • Expanding spray foam can
  • Masking tape
  • Plastic Wrap
  • Box knife

Expanding spray foam is one of the fastest and easiest ways to seal around doors and windows, in gaps in masonry or in any hard to reach place that only needs a little insulation.  Any home owner can tell you how much heat can be lost through the smallest gap around a window in the winter, so using an expanding spray foam will save you money in the long run. There are a few tricks to controlling the foam, but is otherwise easy to apply. 

  1. Unwrap the can completely. Expanding spray foam cans come with an almost full body shrink wrap that must be entirely removed before using. Removing just the plastic around the spray top will not be enough; you need to free the spray hose from the side.
  2. Attach the spray hose to the spray nozzle at the top of the can. This is done by screwing the wider end of the hose to the nozzle with a clockwise motion. When you cannot screw the hose further onto the nozzle, it is completely attached.
  3. Shake the can vigorously for 20 seconds.
  4. Tape plastic wrap flat around the opening of where you will be spraying the foam (only if there is a finish to be protected). You want to make sure that 6 inches around the opening is completely protected by plastic wrap or the foam could leave a yellow stain on your wall, wood or floor when it expands out of the gap.
  5. Insert the tip of the spray hose into the gap and pull the trigger on the can, let the foam fill the space. If you are sealing around a door or window, or any other gap that is long in length, move the can down the length as you see the foam rise to the surface to get a complete seal. When done, wait 20 minutes for the foam to cure.
  6. Trim excess foam off with a box knife and remove the protective plastic that you taped to the opening and you are done.
  7. Tip

    Make sure you are wearing old clothes and shoes when using expanding spray foam cans: The foam will stain and glue itself to fabric and is next to impossible to remove.

    Warning

    Be prepared to use all the contents of a can at once. Written in fine print on the can is the following warning: "Once activated the whole can must be used and any left overs cannot be saved as the foam will cure and hardened in the can."

Things You Will Need

  • Expanding spray foam can
  • Masking tape
  • Plastic Wrap
  • Box knife

References

About the Author

Cassandra Tribe has worked in the construction field for over 17 years and has experience in a variety of mechanical, scientific, automotive and mathematical forms. She has been writing and editing for over 10 years. Her areas of interest include culture and society, automotive, computers, business, the Internet, science and structural engineering and implementation.