Insulation For Attics and Basements

Insulation Types and Options

If you’ve ever touched the surface of a hot stove by accident, you know firsthand that heat can be transmitted quickly between two things that are touching. This very phenomenon occurs in your home’s attic and basement, where the extreme temperature of the outside bangs up against the conditioned comfort of your home’s interior. Fortunately, there is a protective suit of armor available, known in our business as insulation. Measured in terms of R-value (or thermal resistance), insulation is made from many substances and comes in various forms, but generally speaking, the thicker the layer of insulation is, the greater the heat containment effect. As described in Residential Energy (Krigger & Dorsi), here are typical R-values for some types of insulation (the higher the R-value, the better):

InsulAtion Type
R-Value / Inch
Blown Cellulose Loose Fill 3.2 - 3.6
Fiberglass Batts 2.4 - 4.3
Polyisocyanurate Rigid Board 5.6 - 7.6
Polyurethane Spray Foam 6.0 - 7.0


Attic Insulation

Attic and Basement Insulation - PhiladelphiaBatts are strands woven into long rectangular bundles easy to deploy between floor joists in an attic. Loose fill is small chunks or shards usually delivered through a hose (picture at left), and covering everything evenly unless disturbed.

Spray foam typically consists of two chemicals combined at the point of application and expanding, often to fill the space between rafters. Rigid board is most often used on basement or knee walls. The type most appropriate for your home is determined by factors including structure, whether the insulation is in usable space, and budget.

In the past, attic insulation equivalent to R-13 was considered sufficient, but advances in building science and the imperative to save energy have changed that. Today, code in many areas requires insulation at R-39 or higher levels, and homes with attic insulation equivalent to R-60 are not unheard of.

Insulation Replacement or New Instllation

Premier Contractors will consult with you to determine your insulation needs, replace damaged or inadequate insulation, and install new and effective insulation. As a standalone project, adding insulation to an attic need not take more than a few hours.