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

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.

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.

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.

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.

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.

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!)

Stellar progress!
And, progress is good!  

I'm kinda surprised you didn't just put a split hanger up on the roof.
Then it could never drop to the bottom but you wouldnt have to make up that bridge.

Yeah, I'm pretty happy with the progress.  That at least somewhat balances out the discouragement of how much is left to do and the pain in my back and shoulders from working on it!  But seriously, I knew this project was going to be a bear, and it is coming together very well.  Just slower than I would have liked (but not slower than I expected, if that makes any sense).

I didn't really have the possibility of doing anything up top to hold the vent pipe up.  The roof is sort of a two-layer thing, and the holes in the two layers for the pipe don't quite line up with each other.  So I can't get the pipe up high enough to get at it to do anything there (did I mention that the construction of this trailer leaves a bit to be desired?)  And I didn't want to be carving up the roof, because as poor as things in this trailer are, at least the roof doesn't leak.  So when I came up with a pretty easy-to-implement idea for down below I went with that.

Yes, that is excellent progress!  And you've basically worked out the kinks, at least the ones in the implementation if not the ones in your back and shoulders.  

I think you've done a great job.  It should last well and keep the mice at bay as well.

As for the length of projects, I fully understand what you said.  Mine go far longer than I wish they would, but usually not more then twice as long as I expect.  

You're doing great then!  I expect most of my projects to take four times as long as I expect!

... and another factor that I know you know about Gary is that life does and should get in the way of projects.  I "had to" lose about 4 hours of work-on-the-trailer time on Saturday because both of my sons came over for dinner.  It's my older son's birthday tomorrow, and my younger son just got engaged, so there was a lot to celebrate!  They both came over, along with their girlfriend and fiance (respectively!).  I grilled steaks and then we sat around a fire in the back yard.  They all hung around until after 11:00.  It hurts productiveness on the projects, but it's a lot better!

Those are the good diversions.  

I wish our kids were close enough to do that.  Thought we were going to have live-in grandtwins but that didn't happen.  

But I have got a lot done on the truck.  

Nothing Special wrote

....  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....

Yeah, not realistic.  I wrote that almost 2 weeks ago.  But it is done now, and it's out of my drive way!  Well, technically at least.  It's in the street right in front of my house now.  But that's staging to take it back to my folks cabin tonight, so it's still a win!

After my last update I didn't have much trouble finishing it up.  I did lose another evening working on it because I had to run up to the cabin to winterize it (in May???) before a string of 6 nights below freezing.  Then working on it last weekend wasn't so pleasant with highs in the 40s.  But at least the project part was pretty uneventful.

This week I unwinterized the trailer to test the water system.  I did have leaks from two hose clamps that weren't tight enough on lines to the fresh water tank.  The clamp on the outlet line at the bottom of the tank was easy enough to get to and tighten.  But the clamp on the vent line at the top I can't reach without dropping the tank.  Oh well, it only leaks when the tank is completely full, so I can live with that.

Then I had a surprising leak, the drain line from the kitchen sink.  I hadn't touched that in this project, so I couldn't figure out how it could've gone bad.  Turns out it was self-inflicted, but about three years ago.  The first fall I winterized this trailer I had to tie up some heating ducts under a kitchen cabinet.  I put a couple eye screws in to do that, and when I drilled the pilot hole for one of the screws I drilled through the drain pipe that was behind that board without realizing it.  The hole was 2/3s of the way to the top of the pipe, so the water never got deep enough in the pipe to leak out.  But as the trailer sat nose-low in my driveway the water backed up more in that pipe and it did get up to the hole.  So I cut the pipe at the hole and cemented in a PVC coupling.  No more leak!

So now it's ready to go back to the cabin!

Well the trailer was ready, but I had always said I needed to get a weight-distributing hitch before I towed that trailer any distance.  I towed it the 80 miles home from the cabin last month on just a normal drawbar, but I got a weight distributing hitch last week, so last night I got it set up (the reason for getting the trailer out into the street).

I hope I love towing with a weight distributing hitch, because I hated setting it up and I hate hooking it up and unhooking it!  Setting it up was just a lot of hooking and unhooking until I got it right.  Now that I know where it needs to be it only takes one iteration.

The instructions say to hook the coupler on the ball and then use the tongue jack to raise the tongue and the back of the truck 8" - 12".  First problem, I don't think the electric tongue jack is up to that.  It grunts pretty hard just lifting the trailer tongue.  No problem, I have a Hi-Lift jack.

Next problem, after lifting it about 7" I'm looking at the back tires on my truck and thinking "I'm sure glad the trailer is chocked!"  There's no sidewall bulge in the tires, and they're really close to coming off the ground!  OK, so that's as far as I lift it.

Third problem, With it lifted only 7" I can only get the second link in the chains hooked up.  I ended up needing to go to the 5th link before I got it set right, so that won't work.

So instead of jacking up the whole truck and trailer, instead I put the Hi-Lift under a lift bar.  That way I could flex the bar up enough to hook the chain up where I needed to.  But if you've ever used a Hi-Lift jack you know they aren't the most stable platforms to work from.  I could hold it in place pretty well as I jacked it up.  But then to hook up the chain I needed to hold the jack steady with one hand, hold the handle on the latch with my knee and hook up the chain with my other hand.  It worked, I did it about six times on each side of the hitch without losing any fingers.  But it doesn't feel safe.

Unhooking it isn't quite as bad, but it is releasing a lot of force, so it bangs pretty good and stuff jumps around a bit.  Nothing seems to be trying to jump to where it will bite me, but as I said, I sure hope it tows really well to make this all worth it!

Without the weight distributing hitch the back of my truck squats about 2" with this trailer and the front comes up about 1/4"  With the weight distributing hitch the back squats about 3/4" and the front goes DOWN about 1/16".  So it is definitely doing something.  Tonight we'll see how it all works.

Well, congrats but yipes!  Congrats on getting the project done as well as getting the load-distributing hitch set up.  But yipes on the process.  That doesn't sound like fun.  I sure hope you like towing with it connected.

As for the hole in the drain, good work figuring it out.  That one would have taken me a long while to understand.

Good luck on the trip!  Let us know how it goes.

I couldn't understand the leak until I saw it, then it was pretty clear.  Seeing it was a problem though, laying on my back with my head and shoulders under the kitchen cupboard.  The access hole doesn't go all the way to the floor so my back was against a 3/4" wide piece of wood that sat about 4" above the floor.  I hate working inside travel trailers!  (that made the repair a lot worse than it sounded as well)

But yes, we'll see how it goes tonight and I'll let y'all know