underbelly repair

[canman47]

I'm new to the forum here but I've owned Mark's book for a while and have done quite a few repairs on my '71 Fuqua but I'm a bit stumped by my deteriorating underbelly. Most is perfect but any place where it was cut for plumbing or wiring work has fallen off and now animals have gotten in there and had lots of fun. I even had a buck(with antlers) in there the other day. Apparently I can't leave an open space in the skirting! It's the older type of underbelly that's like really thick roofing felt. Nothing seems to stick to it. This site had a link for some stuff called Stick-n-repair but when I read the manufacturers info it distinctly said it was not for underbellies. I've tried framing areas with 2x4's and tacking roofing felt to it but that has fallen down. Plumbers screwed paneling to the existing belly but that all fell down. Can I get the original material somewhere? how do I seal the edges so mice can't get in? Most are small holes along the outer perimeter that I wish I could mend with some kind of super sticky tape. One large hole under the laundry room needs a big patch. Can I use the newer poly type of belly wrap? How could I seal that to the old stuff? The whole system of hanging insulation under the joists seems weird to me. Why not insulate between the joists and put in a solid plywood underbelly?

[JD]

Yes, the poly type underbelly sheeting, which is available at this web site, http://www.mobilehomerepair.com/Order2.html#catalog , is the stuff to use. I use a high strength spray adhesive to install it and that works for the old buffalo board, the cardboard type and the poly sheeting. The product "Stay-Put" is excellent, and also available at that same link. At the home stores, I use 3M High Strength 90 spray adhesive. Do not use 3M 77 which is like hobby stuff. When attaching to the cardboard or buffalo board (sound board) material, you will need to spray the adhesive on cardboard material and let it thoroughly dry. Then spray again with he repair material to install. Basically, you are using the adhesive as a primer on those porous and rough surfaces.

Whenever possible, I will also anchor down the belly material on to rim joists and regular joists by nailing on a strip of 1/4" plywood with the edge of the belly material wrapped up around it. When attaching the belly material to just the old belly material, I make sure that everything is real clean and cut the repair material to have a large overlap to bond to.

As far as insulation placement, I would not veer from the manufacturers design, especially if you live in an area that freezes in the winter.

[canman47]

Thanks, That sounds like a workable way to fix this. I have an old edition of Mark's book and it doesn't say anything about joining dissimilar belly materials. I saw that adhesive on the website and it's a bit pricey but I want to use what works. I'd rather not have to do all this again. How far does it go? I have one large hole about 6 feet diameter where plumbers did some work. The rest is smaller tears where animals are trying to get in. Do you glue the insulation to the belly board before you put it up? All the insulation in that hole is gone. Not sure how to hold up the tarp/insulation while trying to glue it at the same time???

[JD]

It kind of depends on how the factory originally installed their insulation. If they used standard fiberglass batts between the floor joists, then you could do the same by stapling the insulation in place. If they had a thin layer of insulation laying on top of the underbelly material, you could use nylon masons line to make a bit of a "web" to hold the insulation up while installing the underbelly.

The insulation would go up first, then install the underbelly. I would keep the weight of the insulation off of the underbelly repair if possible.

[sixofus09]

I use typar ,the 4'6" roll , for underbelly. I use a special outwardclinch stapler to attach to existing underbelly. I use a hardstapler for the joist. If need be i use strapping on the edges of the frame in the middle to attach the new underbelly if someone completely removed it all. The good thing about the small roll is you can drag it the whole length of the home. i usually do one side with the typar, then put in insulation, the run the next row of typar. I cut around all drops then patch all cuts. I usually rate the job by the age of the home and how high off the ground it is. Then the random dead bodies you find (animals). If your worried about mice im sorry but they will get in if they want to.