Home>Discussions>INSULATION & HVAC>How do I insulate behind drywall?
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cschofer
How do I insulate behind drywall?

Among other things, an energy audit that I had done showed two "holes" in the insulation -- which I believe was caused by a failure of our contractor to install fiberglass insulation in these areas. I am considering two options:

1) Cut out the sections of drywall and install the fiberglass insulation as it probably should have been done in the first place, or

2) Drill a few small holes in the drywall and spray in insulative foam.

I am sure both options would be pretty easy for a seasoned pro, but I am no seasoned pro and the thought of putting holes in otherwise perfectly good looking drywall scares me. Which method would likely be the least intrusive? Most effective? Are there other options to consider?

I guess I should point out that the drywall in question is high on the wall near the ceiling and that the only way to access the area is through the finished side.

cschofer
Re: How do I insulate behind drywall?

I guess I should point out that the drywall in question is high on the wall near the ceiling and that the only way to access the area is through the finished side.

YukSchmuk
Re: How do I insulate behind drywall?

It sounds like the existing insulation is fiberglass so I would cut a hole in the drywall and fix it with the same. If you are not sure about making it look good when you are taping and mudding the replacement piece of drywall, find a closet or place in your garage and practice on the drywall there.

Depending on the size of the hole you need to cut there are different methods for re-attaching a piece of drywall. How big a hole do you need to cut?

cschofer
Re: How do I insulate behind drywall?
YukSchmuk wrote:

It sounds like the existing insulation is fiberglass so I would cut a hole in the drywall and fix it with the same. If you are not sure about making it look good when you are taping and mudding the replacement piece of drywall, find a closet or place in your garage and practice on the drywall there.

Depending on the size of the hole you need to cut there are different methods for re-attaching a piece of drywall. How big a hole do you need to cut?

I am not in front of the wall right now, but off the top of my head, I'd say that I have two areas that are roughly 16"x16" each.

Given a choice, I would rather poke a few holes in the drywall because the repair would be easier. However, there is a nothing behind the drywall to contain the foam. My fear here is that the foam would expand into the large cavity rather than be confined to the area between the studs.

As an aside, I have a similar problem where the contractor failed to insulate around a bathtub that butts up to an exterior wall. In this case, I suppose I could remove the vinyl siding on the outside and spray foam through holes in the siding, but the tub creates a large cavity.

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