Underbelly Repair Upgrade

[RDTC]

I had to do some work under the 5th wheel. Cut the corrugated material open. Never really liked the material. A pain to cut it open to access areas for repairs. Repairs seem to be hit or miss.

Replaced the repair area with aluminum diamond plate. Plan on ultimately covering the whole underbelly with diamond plate. As a start, got the first 12 feet installed.

Can easily remove and reinstall any section. Used foam tape between sections and along the outer perimeter. Installed 2 access doors for the water tank drain control and low point drain. This eliminates additional through holes.

Was going to go with standard aluminum sheet. But, the same thickness diamond plate was 30% less. Probably because that is what the local steel supply had in stock.

[Learjet]

looks nice...but how much weight are you adding? and decreasing insulation?

[BJK]

Nice job . Good idea with the access doors to the valves . I may do the same next time I need to get to the valves

[Lowmiler]

Looks cool, but as Learjet mentioned, have you measured the weight you're adding?

Even a short 35' 5th wheel (not sure what model you have) will have ~27' of underbelly length, which is 8' wide (unless you have a Pinnacle), which is over 200 sqft, and a quick online search shows 3lbs per sqft for 3/16" thick aluminum diamond plate.

Coroplast weighs in around .15lbs per sqft.

You're adding about 625lbs of weight to your rig. Wow.

[BJK]

I have a 2020 Pinnacle . I would only try to put it across the area where the black and gray valves are located . I like the idea of the hatches for easy access to the valves .

[Mopar_Earl]

Originally Posted by Lowmiler

Looks cool, but as Learjet mentioned, have you measured the weight you're adding?

Even a short 35' 5th wheel (not sure what model you have) will have ~27' of underbelly length, which is 8' wide (unless you have a Pinnacle), which is over 200 sqft, and a quick online search shows 3lbs per sqft for 3/16" thick aluminum diamond plate.

Coroplast weighs in around .15lbs per sqft.

You're adding about 625lbs of weight to your rig. Wow.

625 lbs is nothing. His fresh water tank weighs more. Now if already up to GVWR, then yes it's an issue. If there is room on the CC, no worries to be had.

My only concern is the frame flexing snapping off the screws. I'd probably slot the screw holes and use flat washers to allow movement.


Earl

[16WhiteColly]

625 extra lbs. ought to affect the fuel mileage a bit.

[Mopar_Earl]

Originally Posted by 16WhiteColly

625 extra lbs. ought to affect the fuel mileage a bit.

I'm sure, but most RV'ers doing worry about fuel economy or we wouldn't have 12k 35' 5th wheels. Lol


Earl

[SmokerBill]

Originally Posted by Mopar_Earl

My only concern is the frame flexing snapping off the screws. I'd probably slot the screw holes and use flat washers to allow movement.

Earl

I agree. Slots or just oversized round holes to allow for movement in all directions. And maybe add some ventilation panels to prevent moisture buildup and allow water leaks to easily drain out, to prevent rusting on the steel parts and mold and rot on the wood, if any.

Other than that, cool idea. Nice and clean!

[Flintstone]

It’s nice to see another RVr get that It we don’t
Buy these for the mpg. Just the smiles
All our best central Florida

[craigav]

Originally Posted by RDTC

... Installed 2 access doors for the water tank drain control and low point drain. This eliminates additional through holes...

Where did you purchase the access doors? I could use a couple of them as well, or perhaps at least one under my RV, where the slideout motor is. Thx, ~CA

[RDTC]

A few more details. The aluminum is 1/16 thick. Drill oversize holes and used screws with preattached wash and rubber washer. I estimate the total weight will be around 250 lbs.

The access doors are from Amazon. The are boat access panels. Very heavy duty. On a boat, I think they are designed to be walked on.

There was a mylar silver bubble insulation material above the original corrugated plastic. I put that back on the aluminum panels.

I was going to have to do something with the original corrugated. It was hanging done a fair bit in the back. The last trip home we drove through a very heavy rain storm. When we stopped, water drained for a bit.

The question on ventelation is good. There are several holes in the side of the frame. Each jack and the slide out. Hopefully that is enough. I will check it a few times.

[Dannie0429]

Originally Posted by craigav

Where did you purchase the access doors? I could use a couple of them as well, or perhaps at least one under my RV, where the slideout motor is. Thx, ~CA

Just google in rv access doors. It will bring them up.

[RDTC]

Finishing the under belly upgrade to diamond plate aluminium this winter.

Completed 12 feet last winter. Finishing the remaining 20 feet this winter.

2 Sheets short on diamond plate. Should have purchased them all last winter. Price has increase 35%.

Removed all the remaining plastic under belly this weekend. Lots of wire need cleaning up. Tie strapping, adding some wire supports, redoing a few connections. Will probably take a few weekends.

Attached a few pictures of exposed under belly. Pinnacle 32 RLTS. Wish Jayco did a better job.

[RDTC]

Completed the under belly diamond plate upgrade this weekend.

Added an access door for the drian ports. Took a lot of time to fabricate the parts to seal around the gray, black water tank pipes, and gas lines. Rerouted the brake line and improved support for all the gas lines.

[CAG]

Originally Posted by RDTC

Completed the under belly diamond plate upgrade this weekend.

Added an access door for the drian ports. Took a lot of time to fabricate the parts to seal around the gray, black water tank pipes, and gas lines. Rerouted the brake line and improved support for all the gas lines.

How much weight did that add? That is generally the drawback with using something other than the old corofram.

[RDTC]

The diamond plate is 1/16". Width between the frame rails is 72". Total length is about 32 feet. The plate is about 180 lbs. I estimate another 30 lbs in hardware.

Total install weight is about 210 lbs.

[Mopar_Earl]

Originally Posted by RDTC

Completed the under belly diamond plate upgrade this weekend.

Added an access door for the drian ports. Took a lot of time to fabricate the parts to seal around the gray, black water tank pipes, and gas lines. Rerouted the brake line and improved support for all the gas lines.

That's awesome work!


Earl

[h3is3m2n]

The two white tubes, I am assuming are sewer line related. Where did you get all those parts?

[RDTC]

Yes, those are sewer hose holders. They are 6" PVC purchased from Home Depot. The covers and hanger kit is sold on Amazon.

They hold 2 hoses nicely. The size inch size is big enough to hold all the sewer adapters.