How old is the installation? Can you post a picture?
Hello! Just found this forum, what a great resource! I'm helping my father in law with his RV. He had a leak in his fresh water holding tank and when we peeled open the belly covering to fix it, we discovered the supports were totally inadequate. The tank is mounted between the frame rails of the RV which are about 5' 8" apart. The tank is about 54" X 28" X 8" (I'll get some exact measurements later) so we're talking about 450 lbs of load when full. The supports are made from two thin pieces of 2" X 2" angle iron 16 gauge spanning the distance between the frame rails with two flat 2" straps across the middle. Everything is bent, the bottom of the tank is bulging and it looks like it's about to fall out. What do I need to do to support this properly? I'm thinking much heavier angle between the frame rails and four angles under the tank. How heavy does the angle need to be?
How old is the installation? Can you post a picture?
It's a 2010 5th wheel and it came this way from the factory. I don't have a picture. My father in law needed it done so we bolted up a piece of plywood underneath and reinforced that with three pieces of angle iron. I doubt very much that it will last, but it should get him through the summer.
450 lbs of load when full. The supports are made from two thin pieces of 2" X 2" angle iron 16 gauge spanning the distance between the frame rails with two flat 2" straps across the middle.
450 # distributed among four loading locations should be adequate if all materials are steel. The angle steel and straps are at least 20KSI. The tank as you described is sagging because the tank is a thin wall design.
If the 2 x 2 steel angles are secured (bolted or welded) to the RV's frame on regular intervals not exceeding 12 inches - you should be fine.
Ideals to improve the design:
Place a formed piece of sheet metal between the straps and tank. This will help support the thin wall tank.
Add more straps evenly spaced.
Replace the tank with a thicker walled version.
Would still love to see pictures....