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Rim Joist Spring Project

Spring is a wonderful time.  It also rains…a lot.  That means damp basements for lots of homeowners.

The second most important area to seal in a home is also the easiest project! It’s the Rim Joists or Sill Plate.  This is a critical area where the house meets the foundation.

Unfortunately, lots of moisture, air, and even insects and rodents can infiltrate into the house through this structural join.  Closed cell spray foam is the only choice for this area because of it’s amazing ability to seal off all the cracks and crevices, and it resists moisture.

Fiberglass batts don’t fit completely into all those cracks around wall penetrations or against uneven surfaces and it absorbs moisture like that’s it’s job.  Likewise, open cell foam also absorbs moisture like a sponge instead of keeping it out.

This is another Easy 1-2-3 Project with a large impact:

1)      Protect anything you don’t want foamed.  Put down drop clothes, wear a hooded tyvek suit, goggles, gloves, and an OSHA recommended Particulate Respirator with P100 filters for Organic Vapors.

2)      Use a 97% closed cell polyurethane spray foam.  Foam It Green’s spray foam kits are the best option because and you’ll enjoy 24/7 technical support, and ASTM G21 Anti Microbial formula to keep mold from growing on the foam.  It’s easy to determine how much foam you need – add up all the linear feet of wall.  Typically, rim joists are 1 foot tall.  Multiply the total linear feet by 3 inches to get your total board feet of foam needed.  Typically, a Foam It 202 (which covers 202 sq ft at 1 inch of cured foam) will do well for a rim joist project.  Plus, it’s easy to walk with the kit in one hand and spray with the other.

3)      Spray a perimeter around each cavity to make sure the edges are complete.  Then, cross back and forth as you fill the space.  Adjust the speed of your strokes to get the desired thickness.  This is a project that pays dividends all year.  You’ll save money on cooling this summer, have a drier basement, and bring in less cold air in the winter.  Solving this problem now pays you back throughout every season.