Can a DIYer install batt insulation to a Grade I level?
Martin Holladay’s article, “Installing Insulation Right – It’s Hard to do a Perfect Job” had me wondering if a DIYer could install fiberglass insulation “right”. Assuming a DIYer were inclined to install it right, is there any reason why they couldn’t install it to a Grade I level?
Also, in this same article is the following sentence:
“To achieve the R-value shown on its label, a fiberglass batt must be installed perfectly in a wall or ceiling cavity enclosed by a six-sided air barrier.”
What exactly makes a wall cavity a “six sided air barrier”? Should each cavity have sealant at all twelve edges of the six sides? I’m remodeling and will be removing the drywall on most if not all of the exterior walls. Now would be the time to seal the four edges where the exterior sheathing meets the 2x4s and the four edges where the 2×4 wall studs meet the top and bottom plates. Then when the drywall is installed, does it need to be sealed at each cavity even though the airtight drywall approach only shows seals at the drywall perimeter?
I’m only trying to understand how a DIYer can install fiberglass insulation properly and implement the airtight drywall approach as described in Martin Holladay’s article “Airtight Drywall”.
In case it matters:
1300 sq. ft. single story house built in 1960
Wall detail: solid brick veneer, 1/2″ asphalt impregnated sheathing, 2×4 @ 16 o.c., 1/2″ drywall, no insulation
R30 batt plus blown in ceiling
R19 batts in floors
Vented crawl space with 6 mil poly on ground and gas furnace
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