Has your fresh water tank grown a belly?

[chriscowles]

I suspect that, if air is not vented properly, pressure buildup when filling may be able to buckle the floor due to tank expansion at the top. That's certainly not an argument against this reinforcement but someone who sees their tank bulging should rule that out, first.

I'm one of those people. I recently bought an inline hose gauge to measure the usable capacity of my tank. I got only ~25 gallons in my 60 gallon tank before it overflowed at the filler neck. The bottom was bulging to the extent that the drain valve was at an angle, not vertical.

That was a recent observation. I recognized there's a problem somewhere but I have to address that before I can apply this fix for tank sag.

[TitanMike]

Originally Posted by chriscowles

I suspect that, if air is not vented properly, pressure buildup when filling may be able to buckle the floor due to tank expansion at the top. That's certainly not an argument against this reinforcement but someone who sees their tank bulging should rule that out, first.

I'm one of those people. I recently bought an inline hose gauge to measure the usable capacity of my tank. I got only ~25 gallons in my 60 gallon tank before it overflowed at the filler neck. The bottom was bulging to the extent that the drain valve was at an angle, not vertical.

That was a recent observation. I recognized there's a problem somewhere but I have to address that before I can apply this fix for tank sag.

Tank bottoms bulge more often not due to the weight of water in them. Not from trapped pressure, especially in gravity fill tanks.

[chriscowles]

Originally Posted by TitanMike

Tank bottoms bulge more often not due to the weight of water in them. Not from trapped pressure, especially in gravity fill tanks.

I understand that part. I made an error in not considering that it's not(?) possible to cause pressure to push up by overfilling, because it will only flow out the filler neck.

[chriscowles]

Originally Posted by TitanMike

... Edges of tank are supported by factory cross members and they are 27" apart. I installed two pieces of Superstrut from frame to frame, 9" apart and centered. This means that the bottom of the tank is supported essentially by a "grid" of supports 9" X 18". ...

Do I understand correctly that you left the front-to-back supports in place and simply added to the existing structure?

[TitanMike]

Originally Posted by chriscowles

Do I understand correctly that you left the front-to-back supports in place and simply added to the existing structure?

Yes