Attic Insulation Rating

The most effective places to add insulation to older homes are exterior walls attics basements and crawl spaces.

Attic insulation rating.

In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7. Insulation materials run the gamut from bulky fiber materials such as fiberglass rock and slag wool cellulose and natural fibers to rigid foam boards to sleek foils. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.

Rigid foam boards trap air or another gas to resist conductive heat flow. Handy homeowners can install blown in insulation in the attic. Bulky materials resist conductive and to a lesser degree convective heat flow in a building cavity. The higher the r value the better the thermal performance of the insulation.

Inspecting your attic insulation. Now that you ve air sealed your attic and basement check your attic insulation levels and add more if necessary. While there are additional considerations such as venting and moisture problems to take into account when you insulate under floors the united states department of energy recommends an r 25 rating in cold climates and an r 11 in warmer parts of the country. Blowing insulation into walls is best left to the pros because it involves drilling into stud spaces that may contain electrical.

Your attic should have a certain amount of insulation in it and the recommended level of insulation for your attic is dependent on where you live. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. Insulation level are specified by r value. As a benchmark one inch of solid wood has an r value of 1.

R values vary based on the type thickness and density of the material being used. R value is a measure of insulation s ability to resist heat traveling through it. The attic is the easiest place to add insulation to improve your comfort and the energy efficiency of your home. Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces.

The r value per inch for different types of insulation varies depending on the. Insulation with a higher r value will perform better than insulation with a lower rating.