Compressed Insulation Attic

There are two main types of insulation.

Compressed insulation attic.

Then use the numbers in the chart at right to estimate its r value. Most manufacturers use 40 to 60 recycled glass content. Grab a tape measure and a flashlight to see what kind of insulation you already have in the attic and how deep it is. I believe it is r 19.

R value simply means resistance to heat flow. When compressed to less than its labeled thickness glass fi ber insulation will experience a reduction in r value. Loose fill blown in insulation is best for tight spaces or if your attic already has a layer of insulation. The chart below indicates the compressed r value of standard building insulation products when installed in framing cavities with a depth that is less than the labeled thickness of the insulation.

You can compress fiberglass insulation as much as you want i am trying to make a shower niche on a 2x6 exterior wall in which fiberglass insulation already exists. Batt and roll insulation works well between joist and stud spaces or if you have a wide open space or a crawlspace. When it s time to re roof adding 2 of roofing polyiso or a 2 5 polyiso nailbase panel would be sufficient to beat code minimum performance on a u factor basis due to the r11 thermal break over the rafters. Batt and roll insulation and loose fill sometimes known as blown in insulation.

I have a question for you regarding what you wrote. See install batt and roll insulation for details. Pull up and dispose of any material that s compressed water stained or moldy it s useless. This lowers the insulation s r value.

The floor insulation can simply be left in place if you re now heating the attic. These thermal defects undermine the r value of your attic insulation. Yes the compressed r value can be estimated using the following method. To make a niche i want to compress the insulation quite a bit down to only 1 5 or 1 75 inches.

For every x the insulation material is compressed the r value decreases by approximately one half of that percentage or x compressed. Loose fill insulation must be applied using an insulation blowing machine in either open blow applications such as attic spaces or closed cavity applications such as those found inside existing walls or covered attic floors. 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. What is attic insulation.

Let s look at an r 19 batt in a 2x6 cavity step 1. Insulation loses its effectiveness when it is constantly being compressed by being walked on or having boxes stored on it loses its insulation ability.