Roof mounted water tank

I think it would be fairly straight forward to mount, but I wouldn't put that weight and additional height up there. Mount it sort of like solar panels but stronger. Run 3 - 4 channels of Unistrut across four roof members to spread the weight then strap it down with two stainless straps over the tank in the groves made for the strapping. The tank mfg should be able to provide the strap kit.

You'll have at least the 280#s up there that mabynack estimated.

I don't see a problem with using it for drinking water if you keep it clean. Your standard MH water tank is down inside of the MH where it's not subject to direct sunlight. Sitting in the hot sun with moisture in the tank even after draining, is going to grow "things" in it.

Bill

not to mention the additional windage along with everything else up there while traveling.

I wouldn't want to permanently mounted it up there. I'd figure out some way to mount it to tracks but with a quick disconnect for fast removal and install.

But I have to ask, why up there? You don't plan on driving far with water in it do you? And what's it for? Just extra? I assume it's not for drinking, I hope.

I really don't think it's a great idea. In addition to the stress on the roof, you're also raising your center of gravity and will make the RV more unstable. You're adding 280 lbs of weight.