DIY Home Inspection Insulation

Check your region’s insulation requirements and write them down on a piece of paper. Visit the U.S. Department of Energy’s website, type in the first three digits of your zip code, your home’s furnace type, whether it’s new or existing construction and press the “Get Recommendations."

Confirm the batt insulation depth on the exterior walls and shell of the home by measuring the depth of the insulation inside your walls. Take the measurement and multiply it by 3.2 to arrive at the R-value of the insulation. If the walls are 3 1/2 inches deep, the R-value of the insulation would be 3 1/2 times 3.2, which equals 11.2 or R-11. This calculation is only an estimate, because sometimes, the manufacturer makes an R-13 that fits into a 3 1/2 space. Check the paper facing of the insulation, as it could also have the R-value imprinted on it.

Inspect the batt insulation to verify it is not crushed. Crushed insulation loses its R-value, because the insulation's R-value is a result of the trapped air between the fiberglass fibers, not the fiberglass itself. When too much insulation is put into the space available, it causes the insulation to lose some of its R-value, such as when R-19 batt insulation rated for a depth of 6 1/4 inches is in a 5 1/2 inch space.

Repeat this process for internal walls to determine the insulation’s R-value.

Access the attic area to check the insulation. Loose fill insulation doesn’t lay down in long batts; instead it’s blown into the attic using a machine. Climb into the attic and access an area next to a joist. Measure the height of the insulation. If it is batt insulation, use the R-value formula. If it’s fill insulation, approximate the R-value of the insulation by multiplying white, yellow or pink fiberglass insulation by 2.5. For rock wool insulation, look for gray or white insulation with black specks and multiply the depth by 2.8. Identify vermiculite or perlite insulation by lightweight granules and multiply the depth by 2.7. Gray cellulose insulation, made out of newsprint, is calculated using 3.7 times the measurement.

Verify the attic walls have insulation using the same calculation for detecting the R-value of batts.

Go to your basement or crawl space and calculate the R-value of the insulation for your floors or exterior walls. If you find it covered with a vapor barrier, access the far edge of the vapor barrier and remove the staples in that area to measure the insulation. Replace the vapor barrier and re-staple when you are through.

Compare your measurements against the recommended R-values suggested by the DOE’s website. If you find that you don’t have enough insulation, add insulation to increase your home's energy efficiency. The most common place where there isn't enough insulation is in the attic.