Unlevel concrete

[CorbetJackson50]

I have already picked out the spot for the tank (250 gallon (60x36x25) in wall) and I’ve already built the stand. Upon removing the carpet where the stand is going to go I uncovered some cracks in the basement floor and over the 5 foot span probably a half inch unlevel. Should I try to shim this out and if so how would you go about doing it or should I try a thin coat of floor leveling material. If I go with the floor leveling I can’t go too thick because the tank is already gonna be 6 feet tall to the top and 10” to the header above.

 

[BanjoBandito]

How big is the area that needs leveled? I'd look at getting some self leveler if you can.

Custom Building Products LevelQuik RS 50 lb. Indoor/Outdoor Self-Leveling Underlayment LQ50 - The Home Depot

LevelQuik RS (Rapid Setting) Self-Leveling Underlayment helps level floors prior to the installation of ceramic tile, natural stone, resilient flooring, carpet, wood and other floor coverings. This quick-setting

www.homedepot.com

 

[italquam]

I have already picked out the spot for the tank (250 gallon (60x36x25) in wall) and I’ve already built the stand. Upon removing the carpet where the stand is going to go I uncovered some cracks in the basement floor and over the 5 foot span probably a half inch unlevel. Should I try to shim this out and if so how would you go about doing it or should I try a thin coat of floor leveling material. If I go with the floor leveling I can’t go too thick because the tank is already gonna be 6 feet tall to the top and 10” to the header above.

I would just shim the tank , you will be fine . Obviously if any concrete is loose it needs repair but just cracks happen on concrete all the time .

 

[mdb_talon]

I would shim the stand also. I use plastic shims for tanks just to make sure if water does get on the floor they are not soaking it up

 

[BanjoBandito]

It's 2000 lbs. of water alone...if it's me I wanna make sure the floor is level so the tank doesn't impinge under load.

 

[jsker]

With a large tank, I tend to agree with @BanjoBandito. Make a simple form and level the floor and fill the crack.

With a smaller system one can use shims.

If you decided to use shims, I would suggest using a plastic shim. A plastic shim will not deteriorate over time due to moisture.

 

[italquam]

I have used regular wood shims under tanks for years , never an issue . Obviously if you can get it level concrete great but you would have to tear up the original concrete and lay new concrete to repair it correctly . Just a matter of how much of a project you want.

 

[BanjoBandito]

With a large tank, I tend to agree with @BanjoBandito. Make a simple form and level the floor and fill the crack.

With a smaller system one can use shims.

If you decided to use shims, I would suggest using a plastic shim. A plastic shim will not deteriorate over time due to moisture.

Oh man, I gotta hang out with you if 250 is a "smaller system". lol. I have a flooring business mixed into the furniture stores I own, I've seen so many issues from just not doing it right the first time, but it's not my tank and not my place so I'm just here for moral support.

 

[Doctorgori]

I have made a frame from pressure treated wood for large tanks to sit on

 

[mdb_talon]

With a large tank, I tend to agree with @BanjoBandito. Make a simple form and level the floor and fill the crack.

With a smaller system one can use shims.

If you decided to use shims, I would suggest using a plastic shim. A plastic shim will not deteriorate over time due to moisture.

Haha i was the opposite. A durable levelling patch for the much weight is hard to get when less than 1/2" which is why i would go the route i know wont fail with shims.

 

[italquam]

Haha i was the opposite. A durable levelling patch for the much weight is hard to get when less than 1/2" which is why i would go the route i know wont fail with shims.

Exactly my thoughts because that leveling patch will crack over time . Only way to fix the concrete is to redo it properly , otherwise use the shims or even a pressure treated base like doctor gori said

 

[BanjoBandito]

Haha i was the opposite. A durable levelling patch for the much weight is hard to get when less than 1/2" which is why i would go the route i know wont fail with shims.

self leveling concrete can tolerate a PSI of 4000-8000 lbs. (depends on thickness) But it needs to cure for a month. I don't think he's got that kinda time!

 

[WVNed]

Sheet steel shims under where load is transferred to floor. Stack them to get the correct thickness in each spot. Once the weight is on them they will never move.

 

[CorbetJackson50]

Thanks for all the replies. So if I go with the composite shims how about spacing? Obviously under the corners but what more every 12” sound sufficient? Couple pics of stand for reference.

 

[WVNed]

Just under the corners. Commercial grade vinyl floor tile makes good shims and you can cut it with a knife.

 

[Paul B]

I would not put that stand right on the floor anyway. That wood (which looks like pine) will rot under the tank in a few years. I would shim the entire thing to keep it off the floor. But don't use wood shims.

Are those screws stainless or deck screws?

I myself used redwood because it doesn't warp and is good in moisture. I also used hot dipped galvanized bolts. But thats just me and I build to last as long as the pyramids. My last tank stand was galvanized steel and it rusted pretty bad after 40 years.

 

[CorbetJackson50]

Just under the corners. Commercial grade vinyl floor tile makes good shims and you can cut it with a knife.

I’ve got plenty of 50 year luxury vinyl planks left over from doing my main floors

 

[CorbetJackson50]

I would not put that stand right on the floor anyway. That wood (which looks like pine) will rot under the tank in a few years. I would shim the entire thing to keep it off the floor. But don't use wood shims.

Are those screws stainless or deck screws?

I myself used redwood because it doesn't warp and is good in moisture. I also used hot dipped galvanized bolts. But thats just me and I build to last as long as the pyramids. My last tank stand was galvanized steel and it rusted pretty bad after 40 years.


It is pine. I’ve built plenty of stands out of pine before without any indication of rotting. Never put one on concrete though if that’s the issue?

 

[Paul B]

Thats not the issue. The issue is if you put that stand on any floor, any moisture that gets under those long wooden bottom pieces, that water will stay there and rot. If you are only planning for a few years, then it's no problem. I used vinyl tiles toshim mine because even though I used moisture proofed lumber, I didn't want wood touching the floor.
I also didn't wand hardly any wood on wood contact for the same reason which is the reason I built the legs out of 4 x 4's instead of sandwiched wood. But like I said. I build to last forever.

Good Luck

 

[Coinzmans Reef]

The loads on a stand are obviously downward but also side to side and front to back
the legs look OK and the top rails should be fine however the base needs better support from leg to leg. AND DO NOT USE SHEETROCK SCREWS ! they have little sheer strength. Galvanized Bolts or deck screws and lots of them.

Ask your self would you park a small car on it?