Installing Insulation In Crawl Space Under House

Jul 25, 2018

There are different types of insulation, and each type will work well in some applications and poorly in others. Builders began using fiberglass batts to insulate crawl spaces many years ago, before newer types of insulation had been developed. Today, we know that fiberglass performs poorly when installed between crawl space joists. In fact, if often ends up as a moisture-soaked mess on the crawl space floor. Installing insulation in crawl space under house can give you more benefits.

Home performance experts recommend that crawl spaces be encapsulated (sealed) and insulated to help prevent mold and moisture problems, and to make the home more comfortable and more energy efficient. The best time to upgrade crawl space insulation is during the encapsulation process. Unlike fiberglass molding insulation, the crawl space insulation installed by your Basement Systems dealer won’t absorb moisture, fall out of place, or lose its R-value. Installing insulation in crawl space under house comes with a lot of advantages.

Installing Insulation In Crawl Space Under House

Three “target areas” for new crawl space insulation

1. Rim joist. Insulating and air-sealing this perimeter zone is important because it’s a major source of air infiltration and conductive heat loss.

2. Walls. Foam insulation is the perfect choice for insulating crawl space walls. This upgrade moves your home’s thermal boundary to the foundation walls, which makes your home more comfortable and your HVAC system more efficient.

3. Floor. If you live in an area where the ground freezes during wintertime, crawl space floor insulation is a smart upgrade to install. It can be installed over a dirt or concrete floor.

Having a crawl space under your house can make your home colder in the winter than a house built on a concrete slab. Also, mold and mildew can be a problem in a crawl space, so you need to be sure to guard against that as well. To make the floors in your home warmer, and prevent mold and mildew from forming in the crawl space, requires more than just insulation.

Here’s how to go about reducing moisture and insulating a crawl space under your home

Cover Ground:

Start by removing any items stored under your house, as well as any construction debris, such as scraps of wood or broken bricks. Next, even out the dirt in the crawl space, and correct any problems you might have with water standing under your house by filling in any holes or depressions. Finally, cover the entire area under the house with a layer of 6-mil plastic sheeting. Overlap the sheets a foot or so, cut the plastic around piers, and run the plastic all the way to the foundation walls. As an added measure, you can tape the seams in the sheets together to keep the plastic in place.

 Insulate Under Floor:

Fiberglass insulation batts or rolls are the most economical and easiest choice for insulating between the floor joist in a crawl space. The Department of Energy recommends R-11 (3½”) insulation under floors in warm climates and an R-25 (6” to 8”) in cold climates. Install the insulation with the paper vapor barrier facing up toward the heated living space, and make sure the insulation fits tightly between the joists. Hold the insulation in place from below using insulation support wires, or by stapling chicken wire to the bottom of the joists.

Enclose Foundation:

If your foundation isn’t enclosed, fill the space between the exterior piers with bricks, concrete blocks, or lattice panels. To install brick or block walls, pour a concrete footing between each of the piers around the outside of the house, then lay bricks or blocks on the footing. Install foundation vents in the walls, so there is one-square-foot of vent space for every 150 square feet of crawl space. Another option is to make 2×4 frames from pressure treated wood to fit between the piers; then cover the outside with lattice, and staple landscape fabric on the inside to reduce (but not stop) air infiltration under the house.

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If you’re interested in boosting the value of your home or if you’re trying to get your property to sell faster on the market, quality installing insulation in crawl space under house can significantly help the process along. Homeowners and potential buyers can enjoy a certain peace of mind knowing that their basements or crawlspaces are safe from standing water that can start to smell strange over time. With our help, you can prevent creepy crawlers that are attracted to moisture, as well.

Checkout here to know more in detail about How To Insulate A Vented Crawl Space

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