Useable Space Attic Insulation Thickness

R value is a measure of insulation s ability to resist heat traveling through it.

Useable space attic insulation thickness.

Some types of thicker foam board insulation are available but they may need to be special ordered. R 38 is the industry standard and the minimum thickness for r 38 is 12 inches. If your current insulation is only 5 inches deep you ll need to add seven inches of insulation to achieve the 12 inch r 38 rating. You d need a thickness of.

This flexible insulation material is most often packaged in rolls that come in various thicknesses and standard widths usually 16 inches and 24 inches to fit between joists or studs in a house s framing. It comes in standard size 4 8 sheets and smaller sizes in many different thicknesses from 1 4 inch to 2 inches. If you think you re among the 90 of us homes that are under insulated 1 performing a simple insulation inspection will help you determine your insulation needs. For ceilings with an attic space above section 402 2 1 allows the reduction in r value for your zone from r 49 to r 38 wherever the full height of uncompressed r 38 insulation extends over the wall top plate at the eaves.

When blown into attics and wall spaces loose fill fiberglass offers an average r 2 5 thermal value per inch the higher the number the greater the insulating effect. 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. Standard joist spacing for the installation of attic flooring materials is 16 inches on center oc meaning the distance from the center of one joist to the center of the next joist is 16 inches. Having the correct amount of attic insulation can help you maintain a comfortable temperature throughout your home and help save money on your energy bills plus prevent major issues like ice dams in the winter.

The higher the r value the better the thermal performance of the insulation. They come with or without a paper or foil facing that acts as a vapor barrier. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Foam board insulation is easy to use and is a great diy way to add some insulation.

The table below shows what levels of insulation are cost effective for different climates and locations in the home. 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. Insulation level are specified by r value.