R Factor For Attic Rafter Insulation

Contractor or insulation installer s fee.

R factor for attic rafter insulation.

R value does not depend on a single layer of. Owens corning raft r mate attic rafter vents. And owens corning ecotouch high density insulation products are designed specifically for these rafters. The rafters in cathedral ceilings are usually made of 2x10 ft.

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. 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. Type and material of your insulation.

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. The main factors that impact the cost are. Rolls are usually used for long expanses such as length of floor for entire attic while batts are fit between studs in attic rafters. 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.

Fiberglass r 19 batt insulation is about 6 inches thick and is available in 15 inch widths making it the correct size for insulating a two by eight floor joist system. An insulation value of r 38 is at the high end and requires a minimum thickness of 12 inches. Recommended insulation levels for retrofitting existing wood framed buildings. 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.

Inspecting your attic insulation. 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. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. According to home advisor insulating your attic can cost between 1700 to 2100.

Easiest insulation for layperson to install fairly inexpensive r value doesn t fluctuate as with loose fill. R 30c and r 38c are available in both kraft faced and unfaced. Square footage of your attic. The thicker the insulation the greater the r value.