How to Check if Your Your Attic Is Well Insulated

Access your attic by using a ladder to get through the crawl space in the ceiling. Alternatively, pull down the staircase access if your home is so equipped.

Climb up into the attic and make a visual inspection of the insulation in the attic. If you don’t have lighting in the attic, use a flashlight.

Note the insulation depth in the joist closest to you. Use a metal measuring tape and pull out the tape, holding it vertically so it does not bend and place it against a joist next to you where you can easily read the measurements. Make note of the number seen at the level of the insulation.

Calculate the R-value based on insulation depth. The U.S. Department of Energy provides a table to determine R-value by insulation type and depth. For loose fill fiberglass insulation white, yellow or pink in color use the depth measurement and times it by 2.5 to get R-value. For gray and black speckled rock wool, the measurement is depth times 2.8. Gray cellulose insulation made from newsprint is depth times 3.7. The R-value for light-weight granulated vermiculite or perlite insulation is the depth times 2.7. For white, yellow or pink insulation batts, depth times 3.2. Each of these formulas approximate the R-value.

Scan the whole attic area and note where the insulation fits. If you can see the attic joists above the insulation, you don’t have enough insulation, according to the government's Energy Star website. After calculating the existing R-value of your insulation in your attic visit the DOE regional map (see Resources) that defines insulation requirements by region nationally to determine if you have enough insulation in your attic.

Note any low spots in the insulation. This may require you to climb inside the attic and walk its length to verify insulation depth using the method from Step 3. Only step on the attic joists as stepping between them could result in you falling through the ceiling.