Cement Floor only 2.5" HELP!!! - Page 2

CH · #26 11/11/2004, 02:36 PM

Ok, I pm'd you earlier, but I will post my thoughts here. I don't know how big your sumps are, so I just assumed another 300 gal.
1500 gal = 12,510 lbs of weight. This is very similar to some mechanical units we have in buildings sometimes.
Make sure the tank weight evenly distributed by adding a line or two of supports in the middle. In otherwords, dont let it be supported only on the perimeter.
I would suggest leaving the existing slab and going with a 6" pad over it. (4" is probably ok, but 6" will be more of a safety factor) with some welded wire fabric, or if you don't mind spending more, go with the fibermesh reinforced concrete. Depending on how you are doing the finish work for the stand, you could run the plywood or drywall down over the face, so you wont even know it is there. This will also give you a chance to level the surface. As long as you do not cut the existing slab, it theoretically shouldn't settle out of level. I don't think the #4 rebar would be necessary, but it doesn't hurt either.

That's about all I can think of at the moment!

Chris

raskal311 · #27 11/12/2004, 02:03 PM

? If you were to cut of a section of your floor and put new cement in. Since the new cement area wouldn't be the same as the cement around it. Is it possible for the new area to sink below the original floor once the tank is set in?

CH · #28 11/15/2004, 01:42 PM

Raskal311, yes that is correct. The new slab you put in the hole will have the potential to settle. By building on top of the existing, it is less likely to settle, since the surrounding concrete will be helping hold it in place. If you do cut an opening to fill in, it would be a good idea to drill a bunch of dowels into the existing slab (#4 rebar set in epoxy grout, embedded 6" deep, at 12" o.c.) However, with the existing slabe being only 3" or so, there may not be enough strength after drilling (thinner concrete)

TANGBOY5000 · #29 11/15/2004, 05:22 PM

Pour more on top of your floor to create a floating slab. Our concrete floor at the mall is 4", and it cracked from an Oceanic 700. Right after they sealed our floor a nice crack started to eminate from the center of the stand.