R Factor For Attic Rafter Insulation

Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.

R factor for attic rafter insulation.

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. Easiest insulation for layperson to install fairly inexpensive r value doesn t fluctuate as with loose fill. Rolls are usually used for long expanses such as length of floor for entire attic while batts are fit between studs in attic rafters. Type and material of your insulation.

Inspecting your attic insulation. Owens corning raft r mate attic rafter vents. If the joists are 10 inches deep the cavity can take high density r 30 insulation which is 8 1 2 inches thick more than enough for floor insulation. The thicker the insulation the greater the r value.

R value does not depend on a single layer of. R value for fiberglass or wool batts per inch is between r3 and r3 5 pros. Raft r mate attic rafter vents create a space between each rafter for air to flow freely up the rafters and into the attic. If the garage is open to the rafters the boards that support the roof use r 38 insulation between the rafters at the roof if they are 10 inches deep.

R 30c and r 38c are available in both kraft faced and unfaced. Recommended insulation levels for retrofitting existing wood framed buildings. And owens corning ecotouch high density insulation products are designed specifically for these rafters. Existing 3 4 inches of 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. Add insulation to attic. The rafters in cathedral ceilings are usually made of 2x10 ft. If insulation is allowed to bunch against the inside slope of the roof between the rafters air will be blocked before it can traverse the attic.

An insulation value of r 38 is at the high end and requires a minimum thickness of 12 inches. Square footage of your attic. According to home advisor insulating your attic can cost between 1700 to 2100. The main factors that impact the cost are.