Before we weigh the pros and cons of different attic insulation materials, it is important to understand how insulation is measured. Attic insulation is measured by an “R-value,” which indicates how insulation controls the flow of heat and cold through your home. In the Baltimore area, the U.S. Department of Energy recommends R-49 attic insulation; however, building codes only require an R-38.
There are three common attic insulation types used today; batt, spray, and blown-in. Each insulation type has advantages and disadvantages, which we will explain in more detail.
Fiberglass and mineral wool batt insulation are very common in the United States. These batts or blankets usually come in pre-sized rolls that fit between joists and studs in the attic. Because installation is relatively easy and batts are generally the least expensive insulation material, many homeowners try to DIY this option.
However, even though batt insulation is the easiest of the three to acquire, it should still be installed by a professional. It can pose dangers to the skin and lungs and will usually need to be fitted around objects and wiring in the attic. But even professionally installed batts do leave inevitable gaps in insulation, which will lower the attic R-value.
When correctly installed, spray foam can offer some of the best insulation performance with a significantly high R-value. Spray foam is applied as a liquid that becomes a solid foam layer, making for the perfect air barrier that has both durability and longevity.
However, even professionals can have a hard time getting spray foam right. If the spray foam isn’t thick enough, key air leakage sites are missed, or the spray foam contracts and pulls away from the roof framing, then all that increased R-value is lost. Additionally, spray insulation is usually the highest priced option.
Cellulose blown-in attic insulation has the unique ability to fill all the nooks and crannies without the high chance for error that spray foam has. Blown-in insulation is also environmentally friendly, as cellulose is usually derived at least partly from post-consumer and industrial recycled materials.
Typically, blown-in insulation can have an even lower cost than getting batts professionally installed, as it is a relatively easy job for a professional. In fact, if you are getting your roof replaced, don’t miss the chance to upgrade your insulation as well. During a roof replacement, the tube can be inserted through the top of your roof for a seamless experience. The one downside to blown-in insulation is that it does settle over time. However, it still has a longer lifespan than batts.
Any insulation is only as good as the remodeler installing it. In the worst cases, unlicensed and uninsured contractors can void any manufacturer’s warranties with incorrect insulations, leaving you to pay for the fix. That’s why you should do your research, checking Better Business Bureau ratings to ensure that your contractor has a long history of excellent service.
Brothers has been improving Maryland roofs for over 30 years. Our insulation experts will make calculations based on your home’s specific measurements, and our teams of skilled tradespeople can install blown-in insulation in as little as a day. Schedule a consultation to get started today!