Rim Joist: Solved

The Best Material For Insulating The Rim Joist Is Spray Foam

The Rim Joist is the edge of the wood floor framing system. It sits on top of your home’s foundation walls and is attached to the sill plate. In a typical Iowa home, the rim joist area is a large source of energy loss but with proper Rim Joist insulation, you can say goodbye to energy loss. Quite often it lacks the appropriate air sealing. This allows the winter air from outside the home to constantly leak in through the wood joints, gaps, and openings for duct, plumbing, and electric wires.

Typically the rim joist is left vacant or stuffed with some basic fiberglass batt insulation. Since fiberglass doesn’t stop airflow, the cold air will leak in. Another factor with fiberglass insulation, it loses R-value when it is damp. Midwest basements tend to be naturally damp and have condensation issues. The results of poor rim joist air sealing and insulation can be felt throughout the house in the form of drafty rooms and cold floors.

The best material for insulating the rim joist is spray foam. Spray foam is resistant to water, offers superior R-value, and seals the air leaks – all in one application. Home Solutions of Iowa’s two-part polyurethane spray foam not only provides an exceptional R-value (R-7 per inch) but also expands to fill the holes and gaps, stopping air leakages in one simple step.

Simply put the best solution to air sealing and insulation in Des Moines. Contact us for your free estimate today!

Rim Joist Cold drafts
Rim Joist insulation

The Similarities: Rim Joist Insulation

As previously stated, cellulose and fiberglass insulation are two of the most popular options and the least expensive. However, price and popularity are not the only common denominators among these insulation options. They are also easy to install and effective, if properly installed, and have a similar R-value.

The Differences: Rim Joist Insulation

While there are a few other ways in which fiberglass and cellulose are similar, they are actually more different than they are alike. Of the two, cellulose insulation offers more advantages. While neither insulation option acts as an air barrier, cellulose insulation can help slow airflow. Cellulose insulation will also not burn if caught on fire. The same cannot be said about fiberglass. Cellulose also does better in the bitter cold, while heat can be easily stripped from fiberglass. And, lastly, it is easier to do a sloppy job installing fiberglass insulation vs cellulose insulation, meaning that you would get less from your fiberglass insulation, which already appears to be an inferior product.

The Rim Joist Insulation Installation

Now that you know the difference between cellulose and fiberglass insulation, you may be ready to invest in an insulation installation. Here at Home Solutions of Iowa, our team of highly trained and experienced professionals can effectively install the insulation of your choosing. We often recommend our cellulose insulation or even our spray foam insulation, but we can provide rigid foam insulation if you desire it for your home. Contact us today to learn more.

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