Replace urine soaked insulation

Repair help for the do-it-yourselfer.
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Posts: 11
Joined: Tue Apr 30, 2013 10:44 pm
Location: Alabama on the Coosa

I have a crawl space under my double wide trailer, and can actually crawl on my hands and knees without hitting my back, under most of the trailer. When I had some pipes inspected last year, the plumber left a crack in the skirt opening, but said my underbelly looked really good. I had never been under there myself until a couple of days go when the urine smell got unbearable.

A cat has torn out a hole in the underbelly (maybe 12-15 inches in diameter, but along a seam). He has been living in the space between 2 floor joists. It appears the cross supports are not full height, to allow a water pipe to go through the supports, so I don't know the extent of where he has been living/ peeing. There is nothing wrong with the floor above (all are standard plywood, not particle board), so I don't want to go through the floor. Which means I have to cut through the belly to get the stinky wet insulation out. As much as I don't want to, I will do it, and try to enlist a helper. My underbelly is the black stuff that looks like a heavy tarp. I've ordered the Flex-tape tape to seal it back up.

The question is, what kind of insulation is best? I'm thinking the rolls would be best, since I don't know how extensive the problem is. Don't know whether to use faced or unfaced. The faced seems to have a vapor barrior, but I thought that's what my underbelly is for. If I get the unfaced, it won't matter, but if I get the faced, does the paper go against the underbelly or against the wood floor joists? And how do I keep the fiberglass out of my skin? Will long sleeves work, or do I need to wrap my arms in something like plastic wrap?

Am hoping the joists blocked his movement so I only have to deal with a small area. But how do I get the insulation to stick to the bottom of the floor joist? Do I tack it to the bottom of the floor joist just to hold it in place until I get the belly retaped?

Any advice appreciated. I'm in mid-Alabama, if anybody would like to come help <grin>... Thanks, Vicki.
Norm Frechette
Posts: 193
Joined: Fri Aug 05, 2011 7:34 am
Location: Norwich, CT

RiverGirl wrote: But how do I get the insulation to stick to the bottom of the floor joist? Do I tack it to the bottom of the floor joist just to hold it in place until I get the belly retaped?
you could use insulation support wires like these ... de=6720098

they just push into place
Posts: 383
Joined: Mon Oct 25, 2010 9:53 pm
Location: Steuben County, NY

Please, make sure to wear breathing and eye protection when working with fiberglass. You can get disposable protective clothing at a home center.
As to the type, I would use unfaced.
Posts: 622
Joined: Tue Nov 11, 2008 6:12 pm
Location: wisconsin

You want unfaced, like you said your underbelly is the vapor barrier and no need for faced. Long sleeves and gloves should be fine and you can duct tape them if you need to. When I have to do something like this I will pull out all the insulation I can reach through the hole. Then stick my head up through the hole so I can see any other issues. Then start stuffing the new insulation in the hole and use a broom handle to place it where I need it. The insulation usually just sits on the underbelly material so no reason to support it or hold it up. Then patch the hole.
Posts: 72
Joined: Wed Sep 04, 2013 5:53 pm
Location: Holts Summit, MO

When you stuff the insulation in, be sure not to pack it too much. It has to be nice and fluffy to work. It's all the little pockets of air that provide the actual insulating properties. The purpose of the fiberglass is just to create the air pockets.
Don I
Holts Summit, MO
(Central MO)
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Posts: 2690
Joined: Sun Feb 25, 2007 11:57 pm
Location: Fresno, CA

All of the above suggestions are great. I would also use an anti odor spray and be sure all odor is gone before insulating and sealing it back up. I am not crazy about the Flex-Mend tape. Sometimes it does not stick well and the glue tends to dry out and release after a few years. You can still use it, but I would spray it and the patch area with Stay-put or 3-M HD-90 spray adhesive. Let the spray dry until it will not stick to your finger and then press is together in one motion. The stuff can not be pulled and reattached. It's a one-time shot at placing it on. You can tack to the floor joists if your existing underbelly is attached to floor joists. It the underbelly has a big curve belly in it and not attached to the floor joists you need to repair it to be the same. This is where the spray adhesive really helps as it does not need much back pressure to get it to stick. The flex-mend tape only works well when pressed on pretty hard.
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All information and advice given is for entertainment and informational purposes only. The person doing the work is solely responsible to insure that their work complies with their local building code and OSHA safety regulations.