cement question

[ReefWidowed]

So, we are finally getting to the point where we can bring the Zero Edge in. Before it gets put into place for an agonizing week of filling I have to pour a pad of self leveling concrete to make sure it will flow over the sides correctly. I was originally planning something thin like 1inch, but now I'm wondering if that would withstand the weight without cracking. I estimate the entire setup weighing in at just over half a ton.

What would a safe thickness be that could easily be broken apart when we move?

Thanks all!!
Jennifer

 

[itZme]

Congrats on getting it ready! I would think you could build a small wooden platform and level that off before bringing the tank and stand in and placing it. That way you could make the trim around the base match the stand (black painted wood or stained or whatever) and it could be removed later. I would really not want to try to chip up the concrete after you move without damaging the existing concrete. If you feel you absolutely must use self leveling concrete then maybe you should lay down a couple layers of plastic so it doesn't adhere to the existing concrete and could be removed later.

You could also use a short wooden box with open top and fill it with the concrete that way and then add some trim to the wooden box to make it look like it belongs there under the stand.

HTH
-- Kevin

 

[ReefWidowed]

That was the original plan, use 2x4to make a form cover it with painted trim and line it and the floor with painters plastic and maybe form release so that it doesn't stick to the concrete. The floor is really cracked and unlevel, so I think the self-leveling concrete pad is easier than leveling the entire basement floor (which I would do if it was my house).....would 1 or 2 inches of the concrete be enough, or would it crack under the weight and vibrations?

 

[Dina12]

Let me know when you are ready to fill the tank - I am in Parma too. I will bring you over an actual DI tank that can fill you up in about an hour or less. We filled our 125 in less than an hour with these.

My husband works in the water purification field and we have medical grade tanks here.

Ask Murph....LOL...he has seen some of the tanks my husband works with.

 

[oldreefer76]

How out of level is the area the tank is going into, and what brand of self leveling concrete were you looking to use?

 

[ReefWidowed]

Dina, you might be my hero..!! As for the floor, it's your standard cracked basement, so it's not evenly out of level....I'm guessing it's probably about 3/4-1 inch out of level in the area that we were thinking of putting it. I was just going to use Home Depot/Lowes standard Quickrete self leveling...unless there is something better out there. There is also one in the flooring dept, but I can't remember the name of it.

 

[oldreefer76]

What size area are you talking about? 3/4 to 1inch over a 4 ft area is a major out of level

 

[ReefWidowed]

It sure is, mostly because of how it's cracked, sort of heaved up around them...Scott thinks it might be closer to 1/2"-3/4" but he has to re-cut pvc more often than I do :-D. The footprint of the stand is roughly 6'-3' so about 4 inches extra around the perimeter is what I was going for as far as the pad goes...I don't have exact measurements yet because it's still being stored where Scott works.

This tank is my New Years resolution...let's hope it turns out better than that whole gym and eating healthier thing

 

[Kreeger1]

I really wouldn't use self leveling concrete... That really isn't a good choice as it really doesn't get to a level point that would be good for that tank.
I'd use foam and metal shims unless the floor is really bad.
Erik

 

[Aadler]

I can ask my dad tomorrow about the crete thickness, but I wouldnt think 1-2 inches is enough i would think 3-4 at a minimum. I could be wrong, but if the floor is still moving you would want security!

 

[Rhodophyta]

How big is the tank? The concrete might move under the weight if it already shows signs of cracking and heaving. What we did with our 520 gallon tank with a 250 gallon sump under it was cut out the 4" slab and replace it with a 10" slab with three piers.

 

[Kreeger1]

if the floor is moving, the concrete will crack

 

[Howieytown]

Happy New Year,
Since its cracked/heaved I would cut out the area you want to use and then recement it. Make sure the base is packed well and make a new pad 3 or 4 inches thick.
If you move it will just look like a new area of cement in the floor and you wont have to touch it

 

[Tbohinc]

I would build a wood platform and level that with shims a lot easier and if you ask any concrete guy they will tell all concrete will crack some sooner then others but it all cracks

 

[Rhodophyta]

<a href=showthread.php?s=&postid=11496183#post11496183 target=_blank>Originally posted</a> by Howieytown
Happy New Year,
Since its cracked/heaved I would cut out the area you want to use and then recement it. Make sure the base is packed well and make a new pad 3 or 4 inches thick.
If you move it will just look like a new area of cement in the floor and you wont have to touch it

Since you don't own the property, you would have to get permission to replace the floor or any part of it. And replacing part of the floor is more complicated than cutting it out and packing it in. Once the old concrete is cut, it has to be jackhammered out, or pounded into pieces the old fashioned slow but seminally satisfying way with a sledgehammer. You have to dig holes every four feet to undisturbed soil or natural rock. Filled with concrete in a monolithic pour these holes become supporting piers. Then you drill holes in the sides of the old concrete so you can tie the old to the new with rebar. Surprisingly the standard 4" thick concrete slab is not rated to carry the weight of very large tanks, so you have to have consulted a chart to determine what thickness is correct for the weight per square foot or square inch your total filled tank will have. You also need to know what is below that floor. Cracks in basement floors sometimes parallel buried sewer lines or drain tiles. If something like that is found, you may have to pick a different location for the tank. And even if everything goes just right, the new concrete section will broadcast that something had to be fixed, which would concern the landowner. Painting the floor does not always conceal the new sections, so a thicker and more expensive covering system might have to be used to get the approval of the owner.

An alternative might be get a couple steel I-beams and run them on the floor to the footers where they will have support regardless of the floor, and then put the stand for the tank on them. If the footers are not blocked or too distant.

Or you can just build a super hefty stand and hope the floor has settled all it is going to. Set Hardiboard on the floor, frame it with 2 by 4's. Every 12 to 16" put threaded rod through the 2 by 4 frame with fender washers on each end. Shim the 2 by 4's level, line with plastic and fill with bagged concrete. The Hardiboard is optional, but it will make it easier to take up the concrete when you move since a plastic liner sometimes tears or gets holes from the aggregate. Don't use self leveling compound for this. Do the leveling yourself with trowel and screed board. The threaded rod is good since the weight of the concrete will cause the wood frame to spread. You could avoid them by screwing the Hardiboard to the frame from the bottom but then you'd have to plane to level or cut strips of 2 by material to add to the top to get a level frame. Don't remove the frame. Cover it with a baseboard to make it look like part of the stand.

 

[scottfarcuz]

I would be more than a little worried myself. In my experience a basement floor heaving like that is a sure sign of drainage issues. Even 2,000lb's of fish tank wont stop it from rising/settling down the road.

I would avoid putting it near the edge of the slab in any basement.

 

[Kreeger1]

I'd really be worried with the evaporation of a tank that size and style. That kind of moisture can cause some serious damage.

 

[Rhodophyta]

<a href=showthread.php?s=&postid=11497067#post11497067 target=_blank>Originally posted</a> by Kreeger1
I'd really be worried with the evaporation of a tank that size and style. That kind of moisture can cause some serious damage.

If the house is large enough, the moisture added will be unimportant. It will just mean that the humidifier on the furnace uses less water.

 

[ReefWidowed]

I don't think our furnace has a humidifier actually, and we do have one dehumidifier in the basement already, adding a second wouldn't be too bad I hope......Though with the floor issue, I can't help like feeling as if this is going to go the way of all my other New Years resolutions.

Another option I (thanks to Scott's idea) was considering was making a platform with screw levelers to put under the stand it came with and with enough torque I could even make small adjustments to keep everyrhing in level.

 

[Kreeger1]

If the house is large enough, the moisture added will be unimportant. It will just mean that the humidifier on the furnace uses less water.

Not true, and most heaters don't come with the upgrade of having a humidifier.