Now I'm really scared. I am in the process of building a tank stand out of 4 x 4's for the 30 gal and the 20 gal long. I'll bring those two tanks to work. Right now they are on one of those wrought iron stands. The other tanks, 2 20 gals and 2 10 gals, are on wrought iron stands, but they are each sitting on a sheet of plywood. I wish I didn't have to do this. I talked to an architect who said that it would cost me $500 just to take measurements and another $500 for an engineer. All of this limits my breeding stock and raising fry. My club is having a big auction in November. Hopefully, the floor lasts until then. > ...uh, like I said I was tired when I wrote that message - the final number > should actually be 1704 p.s.f. because 21 sq. in. = 0.146 sq. ft. > So it's even worse. If you have a wood floor, don't support your > stands with thin legs; use a plywood or 2x4 'sill plate' to distribute the > load. > > -andrew > I think this confuses the issue. we are really talking about two different things here. The compression and shear strengths of wood are really quite large. The real issue is bending strength, particularly as to its application in the floor structure. The load is distributed by the floor/sub-floor/joist system. An unattached sheet of plywood doesn't accomplish much structurally. For example, my 50 gallon breeder-size is sitting on leveling feet which are one inch in diameter. When I did the structural calculation while building the stand I found that this was more than double the area required. In my opinion 4 x 4's are overkill. The sub floor is designed to transfer the load to the joists. I mean, heck, a fat lady in high heeled shoes puts more of a point load on the floor than that. You can bet the farm that I made sure the tank load was perpendicular to the floor joists though. ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!