I need input on best way to hang new copper or pex pipes from underside mobilehome without opening up belly board

Repair help for the do-it-yourselfer.
For mobile home parts, click here.

Moderators: Mark, Greg, mhrAJ333, JD

Post Reply
Posts: 23
Joined: Mon Jun 06, 2011 2:19 am

Mon Jun 11, 2018 12:21 am

The old galvanized pipes need replaced under a double wide mobilehome. I am going to run new pipes, using a new streamlined path from city water hookup to my water heater etc.

I am trying to avoid ripping open belly board, then having to drill holes through many many joist locations to run new pipes. I also have new Roxul batts already in between floor joists, so trying to slip pipe through all that would also be a major hassle.

My first idea was to find something that will allow plumbing hangers to run along the metal farmings that run across the bottom of home. But I'm not sure there is any way to do that without a special metal drill and a lot of prep time. I've heard about self-tapping screws but not sure if that will go through the thickness of mobile home beams.

My second idea is to somehow run wood strips across the metal beams so that the hangers can screw into the wood. But that still requires finding a way to hang wood boards on the metal beams with special glue that is made for wood to stick to metal without falling apart over the years due to metal expanding and wood wanting to breath. I have yet to find any type of bonding agent on the market for wood to metal that can actually handle the weight of the water filled pipes as well.

My third idea is something I have never seen nor heard of anyone doing before:

is there any laws or reasons I can't just run the main pipes at ground level using some treated 2x4's that are secured into the ground with large nails or rebar using Van hangers. Then all pipes that need to go into the home, would tee off the main pipes and go straight up into flooring where needed. Seems an easier and faster way to secure the pipes rather than trying to screw something into the heavy iron metal framing.

Again, don't want to open the belly or run pipes through all the joists for many reasons related to time,money and effort.

Which idea would you do and how?

User avatar
Posts: 5427
Joined: Wed Feb 28, 2007 8:01 pm
Location: Weedsport, NY

Mon Jun 11, 2018 7:53 pm

There is no easy way to replumb. If you run pipes down the I beam it is not protected from the cold or critters. I have seen pipes run above the floor along the outside wall in a wooden box. I never liked the idea or the looks.
You may as well do it right and get it over with. PEX is easy to work with.

"If I can't fix it, I can screw it up so bad no one else can either."

Posts: 23
Joined: Mon Jun 06, 2011 2:19 am

Tue Jun 12, 2018 12:55 am

I've got the "cold" and "critters"' issues already worked out.

I just need to to know if anyone has ever done what I describe in my 3 ideas I listed and how they made it successfully work.

IF you say that you've seen pipes that have been run around outside walls, then it seems there may not be any laws or ordinances that prevent a person from running pipes at ground level or however they want. So maybe my #3 idea is possible without repercussions when it comes time to sell the home or have it worked on later down the road by pro plumbers.

Posts: 23
Joined: Mon Jun 06, 2011 2:19 am

Tue Jun 12, 2018 3:28 pm

I got through to the city plumber inpector for my area and he told me running along ground not allowed.

But he says self-tap screws into metal will work just fine.

So I got my answer!

Hope this helps others. Don't waste time running on ground. Put up on beams will work and just use felt or other separation material between copper and steel beams to avoid chemical reaction failure to copper pipes.

Posts: 184
Joined: Tue Feb 26, 2008 8:33 am
Location: Anna, Tx

Sat Jun 16, 2018 4:24 pm

I had the need to create a 'hangar' for my A/C lines that run below belly. I measured a 2x4 to fit exactly between the flanged edges of the I-beams. Then on each side of te 2x4, I added a strip of 1/8 x 1" flat bar that was cut about 6" longer than the 2x4 (about 3" on each end). Drilled holes in the flat bar about every 18". I put down a generous strip of E6000 in the back side of the flat bar, and then screwed it to the 2x4. The piece has been hanging for well on 10 years now - and absolutely zero sagging.

you could duplicate - but i would run the flat bar along the 1.5" sides of the 2x4 so that when mounted, the bottom edge of the 2x4 is flush with the bottom edge of the I beams.

I can post a drawing if wanted.

You can get the industrial grade E6000 in a caulking tube.
Opportunity has a shelf life.

Posts: 23
Joined: Mon Jun 06, 2011 2:19 am

Sat Jun 16, 2018 11:22 pm

YES please post drawing!

I was just discussing using 2x4 wedged between beams and your idea seems very thought out and detailed.

I want to show this to my worker that his helping me. We are meeting tomorrow. Not sure if I will be able to get diagram that quickly.

I'll keep checking here for update reply.


Post Reply