Holy sagging water tanks, Batman!

mosseater wrote:
Since I was already having a venting problem with my FW tank, I decided this weekend to look and see why there seemed to be a bulge in my enclosed underbelly.

The venting problem was a pretty simple one. The vent tube was sagging about an inch below where it entered the tank, so there was about 10" of water it that had to be either sucked in or blown out before it could vent properly. A couple wireties solved that in short order.

The bulge was a different issue. SunnyBrook did a nice job installing and supporting the 50 gal. tank between two "Z" struts which were firmly anchored to the frame rails with the tank held captive between them on a 1 1/2" ledge. The problem comes with their rational to support under the tank with a piece of 1/2" OSB sitting on the ledge of the "Z" strut. That, in and of itself, isn't a problem, although it's marginally able to carry the load of 400 lbs of water without bowing. The root of the problem is with their complete lack of allowance for the condesation which forms between the tank and OSB, and slowly rots the OSB, taking with it all support. The wetter it gets, the more water it collects, and the more it rots. The whole center about 1' around was so spongey I could put my hand right through it.

The repair could have taken several paths, but I chose to change out the piece of OSB with 5/8" plywood, which I cut to fit as closely as I could. I bored a 3/4" weep hole in the middle and stapled two strips of plastic, one on either side of the weep hole, to aid in air circulation and drainage of condensation. After got the whole high- tech mess up and in place, I ran two banding straps under the plywood from one "Z" strut flange to the other to help support the tank and also keep the struts for torquing under load. I filled the tank before re-installing the underbelly to watch how it perfomed, and it barely bowed at all. I think it's going to last a long time.

It was also nice to be able to shore up some wiring with cable ties and get a good look at the innards of the beast. At least I know that problem won't rear it's ugly head at some inopportuned moment this season. If any of you folks have some question about the security of your tanks, I highly recommend you take a look. That's a lot of weight hanging under there!

I always travel with full water. No problems with weight. I have a 10,000GVW trailer. Yes, my water tank did try to fall out. The reason for the failure was Winnebago cheeped out and didn’t install the FW tank support bracket. The laid a piece of scrap OSB boards inside the tank support rails. The OSB shifted because the sobs didn't even screw it down. With FW tank halves supported the OSB board fractured. This problem is all Winnebago's. Anybody that has had this problem should call Winnebago's quality manager and ask for support for the repairs.
The Winnebago quality managers name is;
Michael Vanderpool
Mike Vanderpool
Warranty Manager
Winnebago Towables
574 825 5250
mvanderpool@winnebagoind.com