Suggestions for under floor mechanicals

[GuitarmanFL]

Hey Folks:

Newbie here. I have my 27' Overland gutted.

Regarding any new plumbing, wiring, gas lines, etc. Most of these are above the flooring. Any thoughts as to replumbing / gas lines under the floor in the belly ?

Thanks,

B

[truckasaurus]

It would be very unwise to run a gas line in the belly pan unless the belly pan was left quite open. The line may leak at some point.

Regarding the other stuff, I'm going to avoid running stuff in the walls and aim for most of it to be in tracks concealed by cabinetry. Easier access and simpler to insulate well.

[Protagonist]

Originally Posted by GuitarmanFL

Regarding any new plumbing, wiring, gas lines, etc. Most of these are above the flooring. Any thoughts as to replumbing / gas lines under the floor in the belly ?

Best practice is to put your fresh water lines above the floor.

Propane lines are required by NFPA 1192 to be below the belly pan so that all joints— except for the final joint from pipe to appliance— are outdoors, to minimize the potential for buildup of propane in a confined space in the event of a joint leaking.

Wiring can be above or below the floor wherever it is easiest to pull wires. But remember that you want wires to pass through the fewest number of holes, to minimize chafing that could wear away insulation, and you should route it to avoid sharp bends in the wire. If you're going to encase your wiring in conduit, then putting the conduit below floor level might be best. Conduit should be sized so that the diameter is three times the size of the bundle of wires that will be inside. 12vDC wiring should be run separately from 120vAC wiring; don't put both types in the same bundle whether it's in conduit or not.

[Minno]

Do not run gas lines inside the trailer or in the belly. They need to be one length of pipe from the appliance fitting until the gas line is outside of the trailer below the belly pan. The reason is safety. Typically they run down through the floor near the appliance and straight out the belly pan, where you can connect them together or to a manifold under the belly pan. Make all gas connections outside the trailer, except for the final connection to the appliance.

Electrical lines can be run wherever you want pretty much.

Fresh water can be run in the belly, but not advisable if you're going to do any winter or cold weather camping, unless you plan on heating the belly area. Remember to install low point drains to make it easier to drain the system completely and winterize.

Gray water plumbing needs to be installed high enough that water will flow downhill to the gray water tank. That typically means keeping it above the floor. If you run it in the belly pan, you'll be entering the gray tank on the side, and your effective capacity of the tank will be reduced as you'll not be able to fill the tank as full compared to having the drain line run into the top of the tank. The tank will need to be vented as well, and the vent is typically coming out the top of the tank.

The last consideration is that you don't want to cut the frame apart to run plumbing lines. If you do cut into the frame, be sure to reinforce it to maintain structural integrity.

Chris

[idroba]

In addition to all the good advice above, I am not a fan of conduit in trailers for this reason: If the conduit is liquid tight (most these days is glued plastic) an is run through the belly pan with the ends turning up into the rig, and any water gets into the conduit by accident at the open ends, it will eventually fill the conduit. Then you have your wires immersed in water, inside conduit, which is not a good idea.

[Protagonist]

Originally Posted by idroba

In addition to all the good advice above, I am not a fan of conduit in trailers for this reason: If the conduit is liquid tight (most these days is glued plastic) an is run through the belly pan with the ends turning up into the rig, and any water gets into the conduit by accident at the open ends, it will eventually fill the conduit. Then you have your wires immersed in water, inside conduit, which is not a good idea.

Conduit can be installed with drain holes, and has the advantage that it prevents chafing of the insulation.

But it's entirely optional, as long as you provide chafe protection for the wires anywhere they pass through a framing member.

[kdickinson]

water inside of course to keep from freezing and potential damage while towing, gas outside is how I would go (but that's just me)

[MelGoddard]

Most of the ideas presented above, are pretty good informations.
I would add:
Support your wires, pipes, conduits etc. with 'P' clips at every station or frame.
I use ' spiwrap' to protect against chafing wherever the wire/tube/conduit goes through structure. Conduit with drain holes is a good idea.
I also rustproof the underside of the trailer, and any threaded fasteners used.
One other thing: the brake wires might be joined together with "Marrett" wire nuts.
I take them apart, place some silicone grease inside the nut, and refasten them.
THIS; to prevent salt moisture corroding the joint due to dissimilar metals, (copper wire, steel spring nut).
My latest 30' 'Cloud' was rustproofed with 'Diamond.Kote' "Mouse Shield". (Welcome to Diamond·Kote - Diamond Kote) My wife is scared "s....less" of mice.
I also support the brake wires from excess movement, and any wires running below the axles are re-routed above.

Can't add much more.

[shineybullet]

Your thinkng way to much - leave them propane lines where they are where the fresh air can get to them , much much safer

[sgschwend]

I have a heating output line 3" run down and across the trailer to the bathroom side. In the same location two waterlines cross the trailer. There is also a heater port drop heat around the fresh water tank.

25' center side bath model.

[GuitarmanFL]

Hey Guys:

Thanks for taking the time to give me input. After reading your responses - I have to agree with you all. LP most definitely must be safed, under the belly pan. The only propane appliances it looking like I'll be using is a small burner, fridge and possibly water heater.

I'll keep my plumbing also above the subfloor. Electrical stays in the ceiling and walls.

I am wondering about the future and running conduit for an eventual solar recharging system...

I really appreciate your time - it's helpful to walk it through with you guys.

[Jack Moore]

So how do you fix a 1/2 black pipe under the pan? Do we use 1/2" black pipe? Do we connect to that black pipe w/continuous copper line to the appliance?
Thanks,
Jack

[cwf]

Originally Posted by Jack Moore

So how do you fix a 1/2 black pipe under the pan? Do we use 1/2" black pipe? Do we connect to that black pipe w/continuous copper line to the appliance?
Thanks,
Jack

We don't need no steeenkin badges.... but, ours has COPPER for the LP lines. and only rubber/flex lines at the LP bottles.

Secure under the belly pan...usually with insulated strain reliefs...