The floor underneath my fresh water tank was rotten. Just demo'd it. Pulled out the water tank. Plan is to clean up the metal support structure, put in a new floor and install the water tank back. The replacement floor will be about 4x8' with a cut out for the dump valves. Couple of concerns..1) What do I use for the flooring? Need protection from road hazards on bottom and it needs to be strong enough to support a 6' x 4' vinyl water tank (there are 2 metal cross braces). Thinking about a sheet of marine plywood. 2) There was no drain anywhere on the old floor. Should there be one and if so, what kind?Any comments welcome.Thanks!

I would try and find the source of the previous leak to mitigate the risk of it happening again.

I would use treated (yellawood, wolmanized) plywood, probably 5/8" thick.

Why not go with a sheet of aluminum and eliminate the problem forever? For about $300 you can buy a 4 x 8 sheet of 3/16" thick aluminum which, with the metal braces, would be more than strong enough to support the water tank.

Our Phaeton floor rotted due to a cracked basin nut on the shower drain above the tanks. Tiffin has came up with a 1" composite plastic sheet to replace the vinyl clad treated plywood panel used before, this has been the standard for construction for several years now.

I'm a little surprised your Tuscany does not have an insulated subfloor the tanks set on, but use at least 5/8" marine ply, with a 16 gauge galvanized sheet metal cover on the bottom for protection. You can either use contact cement, or construction adhesive to attach it to the ply. If you do not have a fresh water tank drain now, I certainly install one at this time. Don't worry about the size of the tanks, but how much water they will hold. Use 8 pounds per gallon for weight that the floor must carry.

Basement floor replacement under fresh water tank

Bill_Satellite
Explorer II
Jan 28, 2017
That's new to me but looks great. Where did you find it and what does it cost?
Boon_Dogger
Explorer
Jan 29, 2017
I would be cautious about using aluminum over steel cross braces. I'd worry about galvanic reaction.
alanrader
Explorer
Jul 07, 2017
Hi there, according to me, you should go for thick marine or wolmanized plywood. You can also hire a professional who can also guide you the right thing about the flooring. Recently my friend moved to his new house with the help of professional http://movingrightalong.com/business_service_pros.html movers in nyc who provided him moving and flooring service. According to him, they were friendly in nature and provided him quality driven services.
gonesouth
Explorer
Sep 22, 2017
We have been using a product from GE Poly they call "puckboard" intended for lining hockey rinks(the boards) Comes in 4'x8'x1/4" sheets at about $100 each, and appears to be HDPE. Comes in yellow, white. blue, black, and a few other colors. Tough, handles 100 mph hits from hockey pucks and hits from skates and sticks. We have used it for signs that have been up on telephone poles in all weather for ten years now and still look new. It's what I'd use anywhere wood might delam or rot.
AikenRacer
Explorer
Sep 23, 2017
Yes, I did use the HDPE. It was easy to work with, easy to cut. From what I have seen so far, the industry should use it more for RV basement flooring.
Journey24
Explorer
Jun 24, 2024
Years later I have the same issue with a 2000 Newmar Mtn Aire. What did you end up doing?

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Basement floor replacement under fresh water tank

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