Necessary to seal plumbing access holes?
I recently completed a plumbing repair behind the dishwasher and left 2 access holes (say 6″x6″ and 6″x12″) open with the drywall and poly plastic stuff cutaway. Since it’s behind the dishwasher I thought no big deal.
Well, am I gonna have issues with hot moist air escaping through these holes and causing freezing and moisture issues inside the wall over time?
There is plenty of fiberglass insulation behind the pipes, just the drywall and poly have been removed.
This is in Minnesota, so the outside air is very cold in the winter. I don’t really want to disconnect the dishwasher again, but also want to avoid moisture damage in the wall. Thanks!
Mark
Replies
You do run a risk of trouble, especially in such a moist area.
The proper thing to do would have been to tape new plastic to the old and then cover the holes with pieces of thin plywood or some such. Repairing the drywall would not have been unnecessary.
At this stage, though, you may (or may not) want to gamble with leaving it alone. If it were possible to somehow work a piece of plastic behind the unit and secure it in place around the holes that would be a good idea.
I was afraid of that, looks like another open item on the fall project list!
Thanks for the quick reply!
Mark
Of course you could just tear the whole house down. LOL.
I'm just curious. Why are there 2 access holes? One I can see if you had to reach up in the wall to a counter receptacle for power. Where I lived in Canada (at least where I lived)we weren't allowed any plumbing in an outside wall. All pipes came up through the floor. Now that I'm thinking about it some older homes were in the outside walls.
I know about cold weather so personally I don't think you're going to have any trouble. The only time I came across freezing pipes under counters was where a stove exhaust (Jennair) went outside and the cold came into the house through the duct. I've seen a few of those.
roger
It's not freezing pipes he's worried about but humidity getting into the insulation and freezing. Pipes aren't generally placed in outside walls in Minnesota either (which indeed makes one wonder why the holes were needed).
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin
The pipes are indeed running through an outside wall, although they are just 1 1/2" pvc drains and stacks, not supply lines which are all inside.
There are 2 access holes cuz I cut the first one to search for the pipes.
Here's the background story... the deck company broke the pvc elbow on the kitchen drain years ago when they installed the deck to the house rim joist with extra long lag bolts. The prior homeowner disclosed this to us 4 years ago when we bought the house and our inspector noticed some water marks in basement wall framing (but obviously did not see the "repair").
Well, someone used a very badly installed rubber coupling to try and fix the break, which I guess held for some years, but had obviously been leaking for some time. It was really wet, slimy and moldy inside the basement wall framing when I discovered last week. Yuck!
The coupling fell apart when I touched the pipe. Anyway, there is some wood rot where it was leaking but now that it's dried out hopefully it's ok. I heard bleach is not the best for killing mold in/on wood so I just dried and did some sanding to remove the rot. I think I got most of it.
The other thing I was thinking is trying a fungicide like Concrobium Mold Control but I could not find at Home Depot locally. Not sure it's necessary.
The repair was such a hack job I thought about tracking down the deck contractor (I do have the name) but will prolly just let it slide now that it's fixed and the damage doesn't appear too widespread. Thanks again for the comments!
Mark
You can get a decent fungicide at a garden center. Sprays used in the fall on roses, eg. (Do be careful with the stuff -- generally not too toxic, but some of it is very hazardous if you get it in your eyes.)Re drain pipes, you need to make sure that all the insulation (and the plastic vapor barrier) is BEHIND the pipe -- between it and the outside wall. No insulation should be between the pipe and the inside wall, even if it means compressing the FG a bit. (The idea is to keep the pipe as warm as possible.)
So convenient a thing it is to be a reasonable Creature, since it enables one to find or make a Reason for everything one has a mind to do. --Benjamin Franklin