Tank Leveling Advice.......Please!

[naten]

You don't need a plastic barrier. If the existing concrete is fully cured the new concrete will never adhere to it. If you wanted to tie the two together you would have to drill holes into the old concrete and key it together with rebar.
I would use metal shims. We're only talking about 3/4 ". If it was 2" then maybe.

 

[Egon]

^^^ I agree.

In this case the simplest answer is the best. What if, what if, what if lol. Seriously what if a weld breaks while your driving to work and your wheel falls off.........

Shim it, maybe a metal shim is better, I agree with that. Actually I never thought of a metal shim and I think I'm going to start using that on my tanks.

 

[azazal]

what if? only 3/4? only? that's huge over 6 ft! look he originally said wood...metal shims may work...but a 3/4 run out means hes shimming up the whole tank...if we were talking a 1/4 inch in one corner ok but your talking about putting almost the entire weight of the tank on shims....so unless your talking about making steel tapered shims 6ft long x2 plus a 3/4 filler on low end, which i doubt will happen , that leads me to believe you mean shim up the end,,,then what? add more shims every 2 inches or let it ride like that? and thats not a hypothetical statement about the weld...if you shim that much you are changing the weight distribution of a ridged stand and you WILL drive higher loads than the original design...and im telling you from what i know if you start messing with the pounds per square inch of a welded assembly a weld may fail...if it was my tank i would pour a pad...simple easy and the right way to do it...everything else is half assed cobbled together junk

to the OP ...the statement about new concrete not sticking to old cured is true...id skip the barrier completely...

 

[greenterra]

Shimming the stand will not change the weight loads or stress it at all. The shims will be at the same height as your slab would be only pouring a slab is major overkill IMO. The stand only needs the shims under the upright supports, not the entire length. If you want to know the shims will not rot or rust, use plastic shims. It's is common practice with any stand to get it level by shimming it. Being in your basement is no different to being in your house. The stand needs to be levelled and the quickest, easiest way to do that is to use shims.

 

[azazal]

ill agree to disagree...i wouldn't shim half a ton of water but it will probably never be a problem... my work makes me anal...sorry...

metal shims = ez fast cheap and will probably never be an issue

slab= 4 hrs work $50 and you would never think about it again

post a pick of the stand so we can argue the shim placement

 

[Burtess]

I have a 90gal and a 75gal stacked on a 1.5" metal stand and used floor tiles to shim the legs. I don't know exactly what they are called but they are used around here in schools and office buildings etc. They are glued down rigid tiles. You can cut them by scoring with a box cutter and snap them off. I cut them to the same size as the legs and used as many as necessary to get the stand level. They have held up for years so far.

Burt

 

[Pharaoh]

I shimmed my 125 with wood shims because of the basement floor. I raised one end over 1 1/14" and it has been fine with no movement and tons of water on the floor.

 

[Doc_Polit]

Tons of great advice in this thread. Thank you all!

I thought I would proceed with cement but I am facing a few issues:

1) Self-leveling cement is meant for pads 1" or less so I would have to use it to top regular mortar mix or just use regular cement.

2) The floor is out 3/4" over approximately 4.5" of the 6' span. The issue is that it is also not even (flat) over the span either. I am having a heck of a time figuring out how I could build a mold that will keep the cement contained.

3) The floor is "finished". My wife spent a month doing a faux (false) tile look and the tank project cannot damage her finish if I want to remain married.

4) I don't know what the he** I am doing.

Shimming is starting to look better all the time. I would look to rip down 2 oak 2x4's (for the full length of the gap) as they would handle compression much better than standard spruce/pine/fir. I would also waterproof all shims against possible spillage.

I never thought simply locating my tank would be such a pain in the butt.

I will post stand pics (at the chosen location) shortly.

 

[Doc_Polit]

Pics as promised.

The Stand

The Gap

The temporary shim (exactly 3/4" thick)

The end result

 

[greenterra]

As I stated earlier, the stand only needs shimming under the uprights. Shimming the whole length will only aid for cosmetic reasons.