Attic Insulation Rating

Inspecting your attic insulation.

Attic insulation rating.

As a benchmark one inch of solid wood has an r value of 1. Now that you ve air sealed your attic and basement check your attic insulation levels and add more if necessary. R values vary based on the type thickness and density of the material being used. The table below shows what levels of insulation are cost effective for different climates and locations in the 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 higher the r value the better the thermal performance of the insulation. So it s time to pay close attention to what s happening up there. 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.

Bulky materials resist conductive and to a lesser degree convective heat flow in a building cavity. Blowing insulation into walls is best left to the pros because it involves drilling into stud spaces that may contain electrical. 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.

Insulation level are specified by r value. 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. Proper attic insulation is the best way to prevent heat loss in the winter and retain cool air in the summer. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation.

Rigid foam boards trap air or another gas to resist conductive heat flow. Insulation with a higher r value will perform better than insulation with a lower rating. 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. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.

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. The r value per inch for different types of insulation varies depending on the.