R Rating For Attic Insulation

Add insulation to attic.

R rating for attic insulation.

Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Existing 3 4 inches of insulation. 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. It refers to a particular insulation s ability to resist heat flow.

The overall r value of a wall or ceiling will be somewhat different from the r value of the insulation itself because heat flows more readily through studs joists and other building materials in a phenomenon known as thermal bridging. Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation. Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces. Recommended insulation levels for retrofitting existing wood framed buildings.

First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. To achieve a higher attic insulation r value simply add another layer of insulation. Warmer climates only require an r 38 or higher or about 12 or more. 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.

R value is a rating system used for insulation that measures its degree of insulating power. The higher the value the more insulating ability the product has. You can get high performance batts rated as high as r 4 3 per inch. Cellulose insulation r value is r 3 2 to r 3 8 per inch.

R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. R values vary based on. 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. R value is an efficiency rating for insulation.

The r actually stands for resistance of heat flow that is. Standard batts have an r value of r 2 9 to r 3 8 per inch. Batt insulation can be made of fiberglass mineral wool plastic fibers or natural fibers. As a benchmark one inch of solid wood has an r value of 1.

Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value. Cellulose insulation is a type that is typically blown into place. Inspecting your attic insulation.