How To Air Seal Attic Knee Walls

Adding a rigid foam air barrier to the cold side of the batt is a great way to take care of this issue on a knee wall between finished and.

How to air seal attic knee walls. How to air seal a knee wall in a cape. Properly sealing and insulating attic knee walls can significantly reduce air leakage and heat loss between the conditioned space and the unfinished attic. Here s how to locate the leak spots and plug them without spending a lot of money. Fiberglass batts work best if they re enclosed and air sealed on all 6 sides.

This will help reduce the wind damage on the insulation to keep it in good shape as well as increase its effectiveness. Small air leaks into uninsulated attic space are a major source of heat loss in many homes. Installing batt insulation that extends into the attic past the 2 4 studs making sure it doesn t flop over into the attic by adding some kind of bracing and then adding a 2 piece of rigid board insulation on the non attic side of kneewall. Anytime i conduct an energy audit of a cape cod or 3 story colonial or a salt box i know that a good chunk of the homeowner conversation and audit report will deal with the knee walls.

Air seal an attic series. How to air seal knee walls along the roofline. Improving attic knee wall insulation install rigid foam for added energy efficiency. We deal with knee walls in 1930s 1950s all the time 2 3 month at least.

But then for the knee wall it s important to air seal the wall with tyvek or foamboard. Continue the insulation along the roofline to the roof edge figure 1. It is important to choose an air barrier and insulation material that will reduce the air leakage and heat loss as much as possible. Air sealing an attic kneewall the approach used in the video is opposite to what i am thinking of doing.

Cover the insulation with a sheet material drywall or rigid foam insulation that is caulked where it meets the plywood floor sheathing which is extended to the outside wall. The only air leakage in the stud cavities is typically the outlets light switches and access panels. Video done by arlington home energy efficiency team during a weatherization barnraising in march 2010. Square hole that s acting like a chimney drafting expensive heated.

Insulate and air seal the ceiling of the attic room. I disagree with you albeit not that strongly no fight club here that a really solid air seal is necessary over the stud cavities in knee walls. Chances are your ceiling has the equivalent of a 2 ft.