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Attic Insulation - Need to Redo?

After a home inspection (of a tear-down rebuild in 2005), the report had a section that said:

"Fiberglass-Blown, Insulation is installed between roof rafters. 10 inches Depth factor. This is an insulation configuration that I have never seen before. It follows the old style of insulating houses. It is normally no longer done this way for a few reasons: 1) Condensation can get under the roof decking and damage the roof decking. 2) Lack of air flow under the roof decking can cause overheating of the roof shingles and premature aging. 3) You are effectively heating a larger area of the house with this insulation configuration and thus energy bills will be higher than necessary. In addition, there were no styrofoam venting baffles under the insulation so it is unknown whether there is any air space allowing any air circulation. It is highly likely that venting is blocked."

If this is the case, any guesstimate as to how much an attic insulation redo would run?


Timothy Miller
Re: Attic Insulation - Need to Redo?
Timothy Miller

Howdy, how is blown in fiberglass insulation being held up into the roof rafter cavities? Is there any insulation on floor joists of the attic space? If no insulation on the attic floor- ceiling of the rooms below, then adding insulation to the ceiling will help reduce you heating/ cooling bills. Fiberglass insulation is strands of glass and it does not trap water. The inspectors concern is with how the attic is being vented or even if it is being vented. Are there vents in the soffits, eves, and have you checked to see if insulation is covering these vents if so uncover them. Are there any roof vents? Should be one for every 600 sqft of attic space. You could simply drop the roof insulation to the floor recycling it and thus stop the heat at your ceiling inside the room verses stopping it at the roof of the attic.

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