Underside shielding on motorhome

[AikenRacer]

Just got home from a short trip. Saw a piece of aluminum sheet metal underneath that was dragging on the road. Pulled it out and investigated. There is a similar sheet of aluminum underneath the fresh water tank that is rusted on the edges. The bad sheet was under the black/gray tank and fell out due to rust. Trying to find out the purpose of these aluminum sheets. If they are for protection, they are very thin and don't seem to be heavy enough. Taking the RV to a repair shop to see what needs to be done. Also noticed that the liquid tanks bulge some at the bottom....just wondering if that is normal and why they would not brace them better....any comments...

[AikenRacer]

I did call Thor...they were sketchy on this....I am going to did deeper and find out how it is constructed then call Thor and try to speak to one of the guys on the assembly line. I have been to the factory and I think that might be possible. Thanks for the comments.

[AllegroD]

Why not call manufacturer?

[tropical36]

AikenRacer wrote:
Just got home from a short trip. Saw a piece of aluminum sheet metal underneath that was dragging on the road. Pulled it out and investigated. There is a similar sheet of aluminum underneath the fresh water tank that is rusted on the edges. The bad sheet was under the black/gray tank and fell out due to rust. Trying to find out the purpose of these aluminum sheets. If they are for protection, they are very thin and don't seem to be heavy enough. Taking the RV to a repair shop to see what needs to be done. Also noticed that the liquid tanks bulge some at the bottom....just wondering if that is normal and why they would not brace them better....any comments...

And that's all there is between these tanks and the outside atmosphere?
They don't seem to be made of alum. either and more like galvanized sheet metal, otherwise they wouldn't be rusting.
As for your question, I think it's already been answered in one form or the other.

[PatStab]

I have an old 92 American Eagle, all the bottom panels are still intact, the whole bottom is undercoated. There is some rust on a panel in front of the propane tank where the tire has kicked stuff back, I sprayed it to stop it.

[down_home]

I can't see it. Those plastic tanks swell a lot when full. Could be to support them plus road shield. A large rock, or bolt that will go through a 22.5 in tire will easily penetrate a tank.
at any rate I would fix the rust and reinstall 1/4 in or thicker aluminum plates.
If they are aluminum on steel supports galvanic corrosion/rusting is the reason everything let go.
If they contact the tanks, might want some glue between the two so no movement from vibration etc occurs.
Certainly fix the rusted metal and proper coating to insulate steel from aluminum.
Maybe someone else has a better idea?

[down_home]

I can't see it. Thosoe plastic tanks swell a lot when full. Could be to support them plus road shield.
at any rate I would fix the rust and reinstall 1/4 in or thicker aluminum plates.
If they are aluminum on steel supports galvanic corrosion/rusting is the reason everything let go.
If they contact the tanks, might want some glue between the two so no movement from vibration etc occurs.
Certainly fix the rusted metal and proper coating to insulate steel from aluminum.
Maybe someone else ahs a better idea?

[AikenRacer]

I could be a thin aluminum backing for insulation...I am going to check into installing another brace under the tanks. I just don't like the way they sag. After that, I'll get some sort of cover put back on. Thanks for the comments!

[rgatijnet1]

Is it possible that your water tanks were sprayed with spray foam to insulate them and that this sheet was to protect the spray foam? I know on my Monaco spray foam was used to insulate my basement compartments and all water holding tanks.

[Bill_Satellite]

Your furnace also blows hot air into those cavities when running to keep your wet bays above freezing. Without the shield the air would simply blow out. If you never park or travel in below freezing conditions this won't matter. I would do something to seal it back up, however, to keep dirt, dust, debris and other creepy crawly's out.

[DrewE]

Is this possibly foil facing on some other substrate (like maybe foam insulation)? Perhaps the foam or whatever was worn away or chewed by rodents or something.

[crasster]

Are they anything more than some kind of shield from road hazard? Don't see how such thin material would block much other than perhaps deflect some stuff.

[lakebum]

olfarmer wrote:
My guess is that it is mostly to keep mice and bugs out, they probably won't chew through flat aluminum, also it provides some protection for the subfloor and it looks nice. I had an '87 Itasca and now a 2001 Brave, neither one had that problem with the aluminum sheeting, maybe they are making it thinner??

Mine that I pulled off was thin as paper, was actually tearing as I pulled it off. it came off in strips and had to pull numerous pieces to get it all off due to tearing.

[olfarmer]

My guess is that it is mostly to keep mice and bugs out, they probably won't chew through flat aluminum, also it provides some protection for the subfloor and it looks nice. I had an '87 Itasca and now a 2001 Brave, neither one had that problem with the aluminum sheeting, maybe they are making it thinner??

[Ivylog]

And this is on a 2012 DP. There is a 1/4" 2ply alum sign board 4X8' sheet that I would use to replace these areas.