Compressing Insulation In Attic

Yes the compressed r value can be estimated using the following method.

Compressing insulation in attic.

These thermal defects not only undermine the r value of your insulation but they also make rooms uncomfortable and increase your utility bill. When compressed to less than its labeled thickness glass fi ber insulation will experience a reduction. More insulation installation tricks and tips work from the perimeter of the attic toward the door or hatch so that you don t trample all over the insulation you just. Lay a two by four on top temporarily compressing the insulation to a manageable.

For every x the insulation material is compressed the r value decreases by approximately one half of that percentage or x compressed. Let s look at an r 19 batt in a 2x6 cavity step 1. To cut blanket style insulation place the product over a piece of plywood with its paper or foil side down. Simple thermal analysis reveals that if you have 5 missing insulation in an attic bare sheetrock you ll have a slightly more than a 54 drop in r value.

Subtract the cavity depth from the thickness of the batt in inches. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. We can compress insulation and increase the performance of it right up to the point where the main mode of energy transfer is through the material of the insulation itself. Blow in insulation until the hopper is empty.

When installed in framing cavities with a depth that is less than the labeled thickness of the insulation. For wool types of insulation fiberglass mineral wool steel real wool etc while it varies based on material this is typically much denser than we are able to get it via compression on the job site. For the center areas hold the hose level and blow in insulation evenly until you ve reached your level lines photo 6. Move across the attic until you ve hit your desired height at every point.

There was no plywood up there plus it looks like the insulation is not uniformly compressed. There is a path down the center of the attic that has the top 6 inches of insulation above the joists that appears to have been compressed by either some one crawling across the attic or laying a piece of plywood across the joists. The chart below indicates the compressed r value of standard building insulation products. 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 value simply means resistance to heat flow.