Repair of drywall. Noticed bad insulation

yardlady

Background:
We are repairing a section of drywall that was damaged when our hot water heater burst. Second time this has happened first time, the repairs were not as good (we just noticed that when tearing out the current damage).

The drywall is on an exterior wall that leads into the garage.

We pulled down the bad section of drywall only to notice some damage to the insulation combo water/mouse/ and small amount of mold.

To be safe we removed 3.5 ft by 8 ft section of drywall and plan to replace the insulation just in that section. This is lower half of wall, next to sub floor which is being fixed by pros.

I want to just cut the insulation that we can see out and replace just that section. There is a plastic vapor barrier but that has a large hole in one section near an area where some internet cables were run into the home wall. I noticed there was not a good seal around where the cables enter the home. I think the cables go down to crawlspace. I plan to seal this off better.

Questions:

Can I just cut the insulation out, put some in new. Then cover the existing plastic barrier with another sheet of plastic so they overlap?

If I can any suggestions on how to make that seal, tight? Special tape? The garage wall is finished. Home is older built in 80’s.

To fix what I think was part of the caused of the damage……

I’m thinking of getting some PVC pipes and running an extension down from the wall outlet for the cables, about 10 of them that go I guess into the crawlspace. Then I can seal around the PVC while allowing movement and replacement of cables when needed.
When I remove that insulation I will get a better idea on where those cables go. I’m suspecting my damage/water and critter came up through holes created for those cables.

Good idea or not?

gregzoll

Use "tuck tape" to try to fix the hole, in the Vis-queen (ie plastic barrier), if you have to use another piece of plastic, make sure that it is about the same ply. As for the insulation, because you have a vapor barrier, use un-faced, same r-value that is there already. Then just put back a new piece of drywall, put down some drywall mud, then put the paper tape over the seam, then put a knifing of mud, let dry, put another knifing of mud, let that dry, then sand, prime, paint.

You can get some better help at the drywall forum on here, for more clarity in what I stated.

Thadius856

Wouldn't it be easier to remove the last 6" of that piece? When you reinstall, you only have to fasten the full sheet without any cutting.

yardlady

Yes it would be... I do plan to make it so a full sheet fits. I did not trust myself to cut/measure correctly on the first try. So I left a few inches until I could get the drywall sheet and a better ruler. I still have to cut out the section behind the new hot water heater which is bigger than my old model. Someone will have to help me move that out a bit.

I wanted to compare to the other areas in my kitchen but it looks like the drywall does not touch the floor, it sits just a few inches up, and that gap is covered by the trim? Thats the other reason I had to research and still do have to figure out where exactly where to draw my line for the final cut.

Im using a hand held drwall saw a little bigger than a kitchen knife. I don't own any power tools for this job except a drill.

No worries....I will read the drywall forum before I start. I have never hung drywall. I have done touch ups with mud before I paint, and thats it. I do a good job of that because I'm patient.

Got someone else to fix the wire mess that goes into the wall. He is going to install what looks like a breaker box but its for home internet cables/tv cables etc. Looks nice and sits in the wall cavity and will have access pannel in the garage. Cables run from that through conduit to the crawlspace.