R Rating For Attic Insulation

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 rating for attic insulation.

R value is a rating system used for insulation that measures its degree of insulating power. For example insulation that is compressed will not provide its full rated r value. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. 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.

Why attic insulation r value matters for california homeowners at this point. Warmer climates only require an r 38 or higher or about 12 or more. As a benchmark one inch of solid wood has an r value of 1. The r actually stands for resistance of heat flow that is.

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. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. 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.

Insulation typically works by preventing conductive heat flow and r value measures how effective it is at this. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation. Standard batts have an r value of r 2 9 to r 3 8 per inch.

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. Cellulose insulation r value is r 3 2 to r 3 8 per inch. 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.

Batt insulation can be made of fiberglass mineral wool plastic fibers or natural fibers. Add insulation to attic. Recommended insulation levels for retrofitting existing wood framed buildings. Cellulose insulation is a type that is typically blown into place.

Inspecting your attic insulation. Existing 3 4 inches of insulation. R values vary based on.