Best R Factor For Attic Insulation

The ideal attic insulation r value is different than the ideal wall insulation r.

Best r factor for attic insulation.

The higher the r value the better the thermal performance of the insulation. Insulation level are specified by r value. For diy attic insulation you ve got two choices. This material costs less than other rigid foam boards but still offers an r value of.

In general an attic s r value should be between r 30 and r 49. Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Both can be added to uninsulated attics or layered over existing material.

You ll see insulation r values indicated on product packaging and often on the product itself. 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 along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. However as the installed thickness increases for loose fill insulation the settled density of the product increases due to compression of the insulation under its own weight. The higher the insulation r value the greater the insulating power.

Loose fill or batt the common term for blanket insulation. In general increased insulation thickness will proportionally increase the r value. Check the attic walls and floors adjacent to an unheated space like a garage or basement. Insulation is identified and labeled by r value.

R value is a measure of insulation s ability to resist heat traveling through it. Thickness must not be used as the sole factor in determining the r value of loose fill insulation particularly for attic insulation. Note from this chart that the ideal r value differs for each part of your home. For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3.

Your home s r value score will guide you toward the type of insulation you need. Expanded polystyrene eps or beadboard serves as the best insulating rigid foam for homeowners on a budget. Recommended home insulation r values. The table below shows what levels of insulation are cost effective for different climates and.

Warmer climates only require an r 38 or higher or about 12 or more. In particularly cold climates you might go up to. Inspecting and evaluating your insulation. R stands for resistance to heat flow.