Metchosin - Actually there is no such thing as butressing. That should be buttressing. I usually proof my hunt n' peck before I send it, but I was between e's from relatives in Seattle and just forgot. Anyway, If there is a standard for this type of thing, I would love to see it. If you come across any standard drawing, I would appreciate knowing the name of the authority who drew it so I can search for it.

As for buttressing, it's really just filling the space between the tank and the foundation so that the tank doesn't smack the wall.

g