Non-truck question - covering the bottom of a camper trailer

[Nothing Special]

I posted in WHYDTYT about my efforts to mouse-proof my parents travel trailer. I've got a plan for all of the holes (I think there are six). So now I'm trying to figure out what I need to do to cover the bottom of the trailer back up.

It originally had a plastic tarp fastened across it. It was a one-piece tarp, sandwiched between the bottom of the camper and the top of the frame, so I can't do it the same way as it was (I'm not lifting it off the frame!).

I thought briefly about just leaving it uncovered, but that seems like a terrible idea for road spray. And even parked on the gravel at my folks cabin it seems like the bottom of the trailer could get damp.

I thought about coating it with bedliner, but some of the wood looks to have gotten wet in the past, and sealing it up so well that it can't dry out doesn't seem like a great idea either.

So I'm falling back to attaching another tarp. I'll have to piece it together around the frame, and there are crossmembers about every three feet, so it will be a lot of smallish pieces. I could use Gorilla tape to sort of seal the edges. And I'm thinking I'd use clear plastic so I can see through it to see if there are any issues that need attention in the future.

So what do others think? Am I on the right track? Would the bedliner be better? Any other ideas?

I posted this picture before, but it gives an idea of what I have to work with. You can see a crossmember about a foot or so behind the hole.

http://forum.garysgaragemahal.com/file/n58204/DSC_0373.jpg

[grumpin]

I like the clear plastic idea. Not seeing it, I’m not sure.

Could you fasten wood strips all the way around and on the crossmembers? Then you could staple the plastic on and it would be easier to work with in the future perhaps.

[Gary Lewis]

I like the clear plastic idea. Not seeing it, I’m not sure.

Could you fasten wood strips all the way around and on the crossmembers? Then you could staple the plastic on and it would be easier to work with in the future perhaps.

I like the clear idea. But, I've not seen any clear that has reinforcement in it like the blue has. So you can't just staple it on as it'll rip. Been there, done that. You'd need to staple a light strip on the top of the plastic to spread the load or it'll tear at the staples.

Or, perhaps screw a light strip on? That would be easier to remove and replace when/if the time comes.

[ArdWrknTrk]

They make a reinforced polyethylene.

I think a regular roll of 6mil would be in tatters and subject to holes if the trailer is ever on the road.

If you didn't need to see through it, I would have suggested boat shrink wrap.

You definitely need a way to attach the perimeter of each piece -front and back- of the crossmembers.

Pieces of pressure treated framing lumber wider than the crossmember could be pocket or toe screwed between the 'joists', then you'd have somewhere to staple the plastic.

I'd use stainless staples. These are common T-50 and used for screens so as not to weep rust stains.

I think caulk would stay sealed better than any kind of tape in this situation.

[Nothing Special]

They make a reinforced polyethylene.

I think a regular roll of 6mil would be in tatters and subject to holes if the trailer is ever on the road.

If you didn't need to see through it, I would have suggested boat shrink wrap.

You definitely need a way to attach the perimeter of each piece -front and back- of the crossmembers.

Pieces of pressure treated framing lumber wider than the crossmember could be pocket or toe screwed between the 'joists', then you'd have somewhere to staple the plastic.

I'd use stainless staples. These are common T-50 and used for screens so as not to weep rust stains.

I think caulk would stay sealed better than any kind of tape in this situation.

I haven't gone looking for the plastic yet, so I'm not sure what I'll find available. But I'm imagining that I've seen some pretty heavy stuff that I think would hold up pretty well. I don't know what thickness, but think of a ground cloth for a tent.

Good point on the staples Gary! That's what I was planning on using, but I can see those pulling through now that you mention it. I'll have to come up with some way to reinforce them or do something different.

I'll think about putting some wood strips along the crossmembers to fasten the plastic to. But I'm not really thinking that it needs to be a completely moisture-proof seal. In fact, it might even be better if it can breathe a bit. Because moisture is going to get there, and letting it breathe will let it dry out. I figure I mostly want it covered so condensation gets on the plastic rather than the wood, and overlapped where possible/necessary so wind and road spray doesn't get up underneath it when towing it.

As far as caulk or tape, I've had pretty good luck with Gorilla Tape. I've had some on the rockers of my Bronco for a few years. So i think that will work better than any caulk I've had experience with.

Good thoughts, keep 'em coming! I'm hoping to be starting on this part of the project Saturday or Sunday.

 

[ArdWrknTrk]

I haven't gone looking for the plastic yet, so I'm not sure what I'll find available. But I'm imagining that I've seen some pretty heavy stuff that I think would hold up pretty well. I don't know what thickness, but think of a ground cloth for a tent.

Good point on the staples Gary! That's what I was planning on using, but I can see those pulling through now that you mention it. I'll have to come up with some way to reinforce them or do something different.

I'll think about putting some wood strips along the crossmembers to fasten the plastic to. But I'm not really thinking that it needs to be a completely moisture-proof seal. In fact, it might even be better if it can breathe a bit. Because moisture is going to get there, and letting it breathe will let it dry out. I figure I mostly want it covered so condensation gets on the plastic rather than the wood, and overlapped where possible/necessary so wind and road spray doesn't get up underneath it when towing it.

As far as caulk or tape, I've had pretty good luck with Gorilla Tape. I've had some on the rockers of my Bronco for a few years. So i think that will work better than any caulk I've had experience with.

Good thoughts, keep 'em coming! I'm hoping to be starting on this part of the project Saturday or Sunday.

If you want it to breathe, why not Tyvek or the blue Dow housewrap?

Certainly a lot stronger than any poly.

[Gary Lewis]

If you want it to breathe, why not Tyvek or the blue Dow housewrap?

Certainly a lot stronger than any poly.

Yes, something like Tyvek would work well. And it is reinforced.

We had a house with a porch on the north side that was essentially enclosed but they didn't put the windows in. I decided that for the winter I'd enclose it with clear plastic and stapled the plastic to the wood. Didn't last long at all. But by placing lathe strips over it and stapling through it the plastic lasted much longer.

[jdavidsmi]

I believe you would be happy with the tyvek. But I would box in where the pipes come through the floor.

1/2 inch plywood to fit from floor joist to joist, drill a couple of holes where the pipes drop through and caulk with a good silicone caulk. Then paint.

[Nothing Special]

I believe you would be happy with the tyvek. But I would box in where the pipes come through the floor.

1/2 inch plywood to fit from floor joist to joist, drill a couple of holes where the pipes drop through and caulk with a good silicone caulk. Then paint.

Why not Tyvek? Because I hadn't thought of it? That's why I'm asking here, so thanks for the suggestion! It wouldn't be see-through. I like the idea of that to be able to see if there is any moisture building up or new mouse nests to take care of. But I don't think that's all that important. The breatheability and toughness of Tyvek seems like they outweigh not being transparent.

And yes, I'm definitely going to seal up the holes with more than the plastic. I hadn't talked about that here, but I did in the WHTDTYT thread. Basically I'm doing what David is suggesting. Unfortunately I need to cut slots for the pipes rather than close-filling holes, because they need to be able to move fore-and-aft as I install the tank. So I'll need to seal up the resulting holes with spray-in expanding foam (the kind that repels mice). I won't be caulking it because it doesn't need to be sealed against water, and I think the foam will fill the rather large gaps better. And no paint.

[Nothing Special]

Why not Tyvek? Because I hadn't thought of it? That's why I'm asking here, so thanks for the suggestion! It wouldn't be see-through. I like the idea of that to be able to see if there is any moisture building up or new mouse nests to take care of. But I don't think that's all that important. The breatheability and toughness of Tyvek seems like they outweigh not being transparent.

And yes, I'm definitely going to seal up the holes with more than the plastic. I hadn't talked about that here, but I did in the WHTDTYT thread. Basically I'm doing what David is suggesting. Unfortunately I need to cut slots for the pipes rather than close-filling holes, because they need to be able to move fore-and-aft as I install the tank. So I'll need to seal up the resulting holes with spray-in expanding foam (the kind that repels mice). I won't be caulking it because it doesn't need to be sealed against water, and I think the foam will fill the rather large gaps better. And no paint.

Making progress on this, but it's slow. It's really a pain working from a creeper in my driveway, but not nearly as bad as it would've been on the gravel at my folks cabin!

Here's what I've come up with to close of that big hole under the shower (see above for the "before"). There are still gaps around the drain pipes, but there has to be to allow them to move as I slide the gray tank into position. As I said in the WHYD... thread, I'll finish this up by spraying expanding foam (the mouse-repellent kind) into the gaps.

Another example of shoddy design / assembly I found in this trailer (I wonder if it was assembled in Florida?) was the vent tube into the black tank. In the picture below you can see the smaller diameter section at the bottom (about 2" long) that's supposed to go into the grommet/seal on the top of the tank. But the only thing keeping it from going any lower was that small shoulder sitting on the rubber seal. This trailer hasn't been towed much, but the pipe had worked its way down to where it was sitting on the bottom of the tank. Not only does that not work well as a vent pipe, but it also meant that it had dropped below the hole in the roof, opening up (or maybe just enlarging) another place for mice to get in. So I made this framework to go over the tank to hold up the pipe (the C-clamp will go away once I get everything in place and drill some bolt holes). And yes, I'm going to have to use more foam where this pipe comes through the floor.

And I ended up deciding to use a black tarp to cover the bottom, just like it came with. Why that choice? Because that's what I could find. I screwed furring strips around the edge of each section, stapled the tarp to the furring strips, and trimmed it to fit. Then I used screws with washers to hold it in place better than just the staples. And finally I used Gorilla tape to sort of seal the edges. It doesn't show up well in the pictures, but here's the finished product.

I sad "finished" but that's just a few of the sections. I'm maybe 1/3 done with tarping, so I've got quite a bit left. I have the gray tank back in, but still need to get the black and fresh tanks in, as well as spraying in a bunch of foam. I'm hoping to finish it up this week so I can get it out of my driveway this weekend, but I'm afraid that's not realistic. We'll see how it goes. (That's my motorhome under the cover next to the trailer. There's not enough room in front of the trailer for me to park my truck in the driveway, and just barely enough room to get my wife's Jeep Renegade past it. I'm looking forward to getting my driveway back and getting back to working on my Bronco!)