Compressed Attic Insulation Fix

Not so with blown in fiberglass insulation.

Compressed attic insulation fix.

Blown in insulation is satisfactory for many unfinished attics as long as it doesn t get wet or compressed. I suspect the context of the naima calculation is that it pertains to common and customary building practices so i wouldn t attempt to extrapolate their findings to. R value simply means resistance to heat flow. Water is insulation s enemy.

These thermal defects undermine the r value of your attic insulation. Compacted insulation insulation that has been compressed by being walked over or storing boxes on it loses part of its insulation ability. Attic insulation problems are common but fortunately the solutions are simple. The most common forms of insulation today are cellulose fiberglass and spray foam.

Box out light fixtures. Let s look at an r 19 batt in a 2x6 cavity step 1. Yes the compressed r value can be estimated using the following method. Missing insulation at repaired areas in attic it seems pretty obvious that insulation should be put back in place after being pulled back for a repair in the attic but that doesn t always happen.

Fiberglass insulation should never be compressed. For most things we install the tighter the fit the better the item works. Imo insulation is designed to entrap air so the more it s compressed the less air it contains and you end up relying on the conductivity of the material fiberglass itself. It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow.

Subtract the cavity depth from the thickness of the batt in inches. Insulation loses its effectiveness when it is constantly being compressed by being walked on or having boxes stored on it loses its insulation ability. This guide from the department of energy will help you determine what type of insulation you have in your home. For every x the insulation material is compressed the r value decreases by approximately one half of that percentage or x compressed.

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. Different parts of your house may use different kinds of insulation so as you inspect and repair your insulation pay attention to the type that s being used in that area. Insulation is often moved during a repair and is never put back into place.