Open Cell Insulation for Attic

The right insulation is essential for energy efficiency and preventing moisture damage. Foam insulation offers superior energy savings and comfort, but the type of spray foam you choose determines both how much it costs and its moisture control capabilities. Closed-cell foam has higher R-values than open-cell, but it also protects against condensation and moisture in the attic. In our region, closed-cell foam can be sprayed directly to the underside of rooflines without attic ventilation or it can be sprayed on the attic floor as part of a cold roof system. The latter option is best for our climate because it prevents condensation and provides the highest R-value possible in the attic.

In addition to its high insulating value, closed-cell spray foam acts as a moisture barrier, protecting against mold and bacterial growth. It’s also a good choice for humid areas because it prevents water vapor from penetrating the attic and damaging wood materials.

Open-cell foam, on the other hand, is a less expensive product that can be used in unvented attics, walls, ducts, and crawl spaces. It fills cracks and joints, reducing airflow and increasing R-value in those places. It’s also a great air sealant, keeping your conditioned indoor air from escaping into the attic and infiltrating the house through walls and ducts.

Unlike closed-cell spray foam, which has small pockets of air that cluster closely together, open-cell foam is more pliable and lighter in weight. This makes it easier to cut and install, and it can be applied to hard-to-reach nooks and crannies that are difficult for other insulation products to reach. This type of spray foam insulation is not only affordable, but it can also help reduce sound transmission between floors and other rooms.

If you’re worried about attic moisture problems with Open Cell Insulation for Attic, keep in mind that the problem is most often caused by poor attic ventilation or a lack of vapor retarder. As long as you follow the recommendations of your spray foam installer and use a vapor retarder, you should not have any issues with open-cell spray foam in an attic.

Another possibility, which William Miller suggests, is that the attic is not properly conditioned. If this is the case, make sure to condition the attic and test the airtightness with a blower door to commission it. Alternatively, you could use a low-cost thermo-hygrometer and monitor the attic’s temperature and humidity as recommended by Skye Dunning see her comments below. Then, you will be able to find out whether the issue is with the attic or with the insulation. If it is with the attic, you can fix it quickly with a simple air leak repair.