HAAG Certified Reviewer

Which is the most common type of residential insulation used in exterior walls?

1. Blown in fiberglass

2. Cellulose

3. Fiberglass batts

4. Sprayed urethane

The correct answer is: Fiberglass batts

The most common type of residential insulation used in exterior walls is fiberglass batts. Fiberglass batts are prefabricated insulation materials made from a mixture of glass fibers and are manufactured in various thicknesses and widths to fit standard wall cavities. Their widespread use can be attributed to several factors. Firstly, fiberglass batts are relatively easy to install, making them a preferred choice for both DIY projects and professional contractors. They can simply be cut to size and placed in the wall cavities without the need for specialized tools or advanced techniques. Secondly, they offer good thermal performance, effectively reducing heat transfer and helping to maintain comfortable indoor temperatures. The R-value, which measures the insulation's effectiveness, is generally high for fiberglass batts, contributing to energy efficiency in homes. Furthermore, fiberglass batts are cost-effective compared to some alternative insulation types. They provide a balance of affordability and performance that many homeowners find attractive when choosing insulation materials for their exterior walls. In contrast, while blown-in fiberglass and cellulose insulation provide excellent coverage in attics and complex wall cavities, they are less common in straightforward applications like standard exterior walls. Sprayed urethane insulation, although very effective and offering a high R-value, is typically used in specific applications and can be more expensive