Under-belly cover

[BruteForce]

**I couldn't find an area to post this in, so I'm sure if one exists, a moderator will move as appropriate**

Today, while installing scissor lift legs in the rear of my rig (the OEM units were garbage and kept binding, so I removed the electric unit), I noticed that the plastic coated cardboard covering the under-belly was coming loose mainly along the middle; it was bowing quite a bit in the center and there was water accumulating. It would seem that the center "screws" or whatever they are/were had come undone and the entire mid-section was hanging low.

How to fix?

I'm thinking about cutting about 6x pieces of sheet metal (maybe 2" wide), drilling holes in the frame rails and using those to hold up the under-belly sheet.

Any ideas/fixes appreciated.

 

[Lynn1130]

It sounds like you have a leak of some sort from the tanks that is accumulating on top of the coroplast (sp). You may want to drop the coroplast (wish I could spell that) and check for leaks from the tanks or the crossover. Likely it has also had an impact on the particle board under the tanks.

 

[MTPockets]

Have you driven on wet roads? Water can enter when driving in the rain. I've had that happen; I drained, then sealed around the wheels where mine had 1/4" gaps .

 

[BruteForce]

Have you driven on wet roads? Water can enter when driving in the rain. I've had that happen; I drained, then sealed around the wheels where mine had 1/4" gaps .

Yes, last two trips home were in the rain, so I think this is the likely source of the very little bit of water. The bigger issue is the center studs/screws seem to have broken or are now non-existent.

 

[Garypowell]

You mention water and that could cause the bowing you mention. But to me a little bowing is natural. But you need to investigate the source of the water. It could be a leak somewhere or like in my case simply road water.

You have to be careful in adding any structural support. For one thing there is the weight consideration and then the screws to hold it up if put in blindly could puncture one of the tanks.

What I have done is cut a three sided slit in the coroplast and use this as a flap to open and see inside and possible know what is going on. Be really careful and only cut as deep as the plastic....again tanks and wires all through the bottom.

Make the one side that is still attached be towards the front so that once you repair this flap if it ever comes open the wind of your motion will tend to keep it closed rather than rip open the bottom.

When you are ready to close it up I use a small piece of wood that is larger than the flap and put it across the far end. Since it is bigger than the cut it extends on either side. Take some screws and hold it in place by screwing it in place to make it secure. Then move the flap in place and screw it to the exposed piece of wood. The tape the cuts closed and you are done.

This method gives you a good way to get back in again if needed.

Good luck...once you get inside and see what the problem is let us know.

 

[BruteForce]

Just to be clear: Water is NOT the issue. The primary issue is that the center screws/bolts that were holding this up are no longer attached. The sides are still good, but at least 3-4 center bolts/screws no longer exist, causing it to bow in the center. Best method to fix?

 

[JohnDar]

If the bolts just worked loose and fell out, you could remove one from the side and take it to find replacements. If they corroded and snapped, same thing, just install them close to the originals. Or, run a length of steel strap (or small angle iron) from beam to beam. Are you sure the droop is actually under an existing crossmember? Mine droops in spots where there isn't anything under it.

 

[BruteForce]

I can see the holes in the "board" where the screws/bolts used to be.. and that's where the bowing is. I have no idea what they were attached to - hence my idea of 3-4 aluminum straps from frame rail to frame rail to help hold this stuff up.

 

[jnbhobe]

I have angle iron under my water tank like you want to do, I have done it on every rig I've had. The cloroplast was held up with 1/4 X 1 Tec screws ( self drilling ) and fender washers.

 

[Birchwood]

I spray all the coroplast screws with Fluid Film or they will rust and head will break.I would just drill a new hole close to the old one and use a new screw.
If you have water accumulating from traveling in the rain you could drill a couple small holes in the coroplast only to drain the water.

 

[sengli]

Ditto on the small holes in the coroplast. If any water does accumulate, it will go to the lowest point, put a small hole there and it will self drain.

 

[Bob&Patty]

Drill small 1/4" holes at the low points in the coroplast. Do it with a piece of rubber hose on the drill bit so you cant go any farther than a 1/4" into the coroplast. It will drain all the water out. If you do have a leak...you will know it, because water will keep dripping out. Drilled holes in mine years ago and no problems.

 

[wdk450]

Coroplast (Corrugated Plastic) is a polyethelene product, and is available in single WHITE 4X8 sheets at Home Depot. Home Depot can order the BLACK 4X8 sheets with about a week's lead time (free shipping), but you can only get a pack of 10 sheets that way ($250). TAP plastics, a plastic supply chain here out West, had the black 4X8 sheets in stock (at least at their Santa Rosa store) and wanted $35 a sheet. The stuff under the trailer is about 6 foot wide (from my memory). Lowes has the self drilling screws and fender washers, but I would drill a pilot hole for any new screw holes, as you are going into steel support beams. Drain holes are a good idea on both the coroplast and the OSB fresh water tank support (if you have to pull and replace that due to wood rot).

Most everbody's coroplast sags some, sometimes its just missing screws, sometimes its water.