Is your house too hot in summer or chilly in winter? You might have an insulation problem! How do you know if your insulation is no good? Professionals use what’s known as R-value to determine if there’s enough insulation in an attic. But you can get an idea of your insulation’s R-value before you call in the pros.
You’ll need a few things, including a headlamp so that your hands are free to measure the depth of the insulation, a tape measure, and a respirator mask, which protects your lungs from insulation particles. Once in your attic, it’s important that you only step on 2x4s. Otherwise, you could go right through the drywall into the room beneath you!
It’s easier to measure the depth of your insulation if it’s at a relatively uniform height. Unfortunately, not everyone is that lucky. If your insulation is flatter in some places and mounded in others, you’ll need to take multiple measurements and average them out by adding the heights and dividing by the number of measurements.
Once you have that measurement, it’s time to calculate the R-value. This number depends on the type of insulation in your attic.
- Blown Fiberglass – multiple the depth by 2.5
- Blown Cellulose – multiple the depth by 3.4
- Fiberglass Batts – multiple the depth by 1.25
If you’re unsure what kind of insulation you have, the following descriptions can help.
Do you think of insulation as pink? Then you’re imagining fiberglass, but that’s not the only color this insulation comes in. Batting can also be yellow, black, blue, brown, green, or white. Fiberglass batting is rolled into place and looks more fibrous, while blown fiberglass is a bit fluffier and looser. Blown fiberglass is also commonly white.
Cellulose is basically cut-up newspaper and has a chunkier and denser appearance than fiberglass. Because of its source, cellulose insulation is gray, but you may notice some colored pieces in the insulation.
Ideal R-values for Attic Insulation
Once you determine the type of insulating in your attic, you can do the calculations to reveal the R-value. But what is a good R-value? It varies depending on the climate in which you live, so you have to be careful that you’re not reading R-values for a different location. Fortunately, the Department of Energy has maps and charts describing the ideal R-values based on climate and where the insulation is used in a building.
In most of Arizona, an R-value between R-38 and R-60 is preferable for attics. However, in the very northwest and southeast parts of the state, an R-value as low as R30 might be fine. Finally, the southwest part of the state has an R-value range of R30 to R49, and you don’t want too much insulation in your attic.
Your insulation is good if it stays within those R-values. However, if it’s much lower than those R-values, your insulation isn’t working as hard as you want it! Then, it’s time to call in the professionals like those like King Insulation to get your insulation up to spec, so your home will be more comfortable!