Sealing holes in sub floor

**patrick1** · 11-30-2011, 09:11 AM

Hey guys,

Every single plumbing fixture cutout in my house looks like this.

I have discovered that i have a a problem with mice so I want to seal these gaps. Any suggestions on what to use to cover these? I am sure plywood would work but it seems like I would have trouble cutting it to fit around the plumbing.

**Gary Swart** · 11-30-2011, 09:18 AM

I'd use plywood and make the cutouts as close as possible. Then fill in the gaps around the pipes with spray foam insulation. Make the plywood wider/longer than the hole and use screws to secure it to the sub floor. This doesn't have to look especially pretty.

**patrick1** · 11-30-2011, 09:21 AM

ok I will do that, I wanted an easier method... lol But I should just do it right.

**patrick1** · 11-30-2011, 09:48 AM

Do you think the mice will chew though the foam? My original plan was to lay down some wire, almost like chicken wire but it has really small holes to keep them out then spray foam though it to insulate then tack on a roof shingle to make sure all the draft is gone. But the plywood seems a like a more legitimate fix.

**Gary Swart** · 11-30-2011, 11:33 AM

Well, you might form some 1/4" hardware cloth around the pipes, staple it to the plywood, then apply the foam through the hardware cloth. The hardware cloth would help keep the foam in place for the short time it take to set up which would be an added benefit. Hardware cloth without the plywood might be OK, but I wonder if there would be a lot of ooze out to deal with. You may have a good point about the mice eating through the foam, but the hardware cloth will prevent that.

**patrick1** · 11-30-2011, 12:18 PM

I will pick up hardware cloth tonight and staple it down to at least keep them from coming into the house. after that I need to get rid of the draft I really wanted to used the shingles since i can easily cut them with a utility knife but I think it might be jerry riggin it lool.

**bluebinky** · 11-30-2011, 03:09 PM

The tub drain should remain accessible.

I'm faced with the same problem.

**patrick1** · 11-30-2011, 03:12 PM

If I covered it with either plywood or the hardware cloth it would be accessible later on the only thing that would make it difficult would be foam.

**Gary Swart** · 11-30-2011, 03:23 PM

You might have to access the tub drain maybe once in 20 years, and removing foam would not be especially difficult. Could be a little messy with small pieces, but easy to vacuum them.

**bluebinky** · 11-30-2011, 04:01 PM

Originally Posted by Gary Swart

You might have to access the tub drain maybe once in 20 years, and removing foam would not be especially difficult. Could be a little messy with small pieces, but easy to vacuum them.

I agree.

I saw the accessible requirement in the UPC, so it might not pass inspection... If I had mice invading, I wouldn't fret about something easily corrected later for very long...

**patrick1** · 12-01-2011, 12:25 PM

Well what I ended up doing was laying a shingle down then I put the hardware cloth over that but i left one side un nailed and shot form up though the open side then nailed it all shut. I have no holes under the house anymore!!! I got 2 mice last night in traps baited with Peanut butter.