The tank bay of my coach was so corroded I was afraid to fill the fresh water tank. The tank sits on the floor and holds up to 82 gallons, around 650 lbs. The floor was beginning to sag.

I decided it was time to repair the floor. I removed the tank and was surprised to see how bad it was.

After the MN GTG, I cut out most of the damaged floor. Not much left to hang a new floor on.

I had been planning to just put in a temp plywood floor for the GTG next week. I had forgotten there is no water at the sites!
So, I not only needed a floor I needed a load bearing floor!

I decided the first thing needed was to reinforce the outside corners with angle steel. I used a 16ft 2 x 3 with the two inch side vertical. The 2 inch side fits below the door gasket nicely. The 3 inch side becomes the floor flange.

Since some of the metal is so corroded, I decided to bolt the steel in rather than try to weld. I will ultimately remove the steel and bed it in epoxy to seal and bond it.

Another 16ft, wheel to wheel, on the driver side

I installed two more transverse angles to span the front and rear corners of the bay. With that I will have sturdy flange all around for the plywood floor and tank.

It is certainly convenient that you have your water tank in a bay. Supporting the extra weight of water is important. It appears you have thought this project through. You can be ready for real off grid camping.

A few more details and ready for plywood floor, then replace the water tank.

With help from my fearless assistant Dana we now have a floor

Now we can slide the tank in and hook up the water lines...

Tank is back in and filling!

Lines are connected, pump works. Just a few tank sensor wires to connect.

Eventually I will epoxy all the steel and wood.