Floor way out of level.

[JDJP]

Build a "form box" using something like Redfish's idea. Build it 6" larger than your current stand dimensions, this could be done relatively easily with 1x4 or 1x6 stock. When you have the form box built fill it with quick crete let it set for two weeks and put your stand on top of it. Your 180 sump will go inside the stand and already be level.

Why 6" larger?

 

[JDJP]

Here's one of my build threads that shows exactly what I did and used.

https://www.reef2reef.com/threads/rebirth-of-my-octocab-tank.204901/

Nice, but why is it necessary to rip the boards couldn't you level it inside the frame without filling it all the way to the top?

 

[Matthew Frost]

Why 6" larger?

You want a lip all the way around the outside. You don't want the edge of the stand to sit on the edge of the concrete pad because it will encourage the concrete to chip/break off. Concrete has a huge compressive strength but virtually zero tensile strength.

 

[davocean]

Nice, but why is it necessary to rip the boards couldn't you level it inside the frame without filling it all the way to the top?

It's a lot easier, for me anyway, to rip the form and just pour crete in and just screed the crete level, and in my case I just left the form boards in place, everything got covered by stand skin and baseboard anyway.
I think the way you stated is harder to make crete perfectly level, unless you are a decently skilled mason, I'm just so so there, I'm a carpenter/contractor by trade so the frame was easy, but anyone w/ any diy skills can do it.

 

[davocean]

You want a lip all the way around the outside. You don't want the edge of the stand to sit on the edge of the concrete pad because it will encourage the concrete to chip/break off. Concrete has a huge compressive strength but virtually zero tensile strength.

Also why I left my form in place, and laid hardy backer board on top, and this allowed flush pad

 

[jjflounder1]

Could be another option. I wonder if i could put some plastic down underneath it to make it not permanent.

If you simply skip using a bonding agent in between . . ( Unless the garage floor is brand new )

Then you can build a simple 4 by 4 rectangle for the added height

 

[jjflounder1]

People in our hobby greatly underestimate the strength of wood.

Can't help it welders / machinist all my life ...
Just got comfortable working with metal

 

[JDJP]

Really great advice everyone, i really appriciate it.
Right now im thinking getting 4x4s or even 4x6s ripped so they are a couple inches shorter on the one side. Then just pouring concrete inside that frame to level is my easiest option.

Then i have some extra height, and i dont need to build a seperate frame .

 

[davocean]

We usually don't advise 4x as it tends to twist and bow, and it's harder to rip clean since you typically have to run a blade on each side as a skillsaw will not go all the way through.
2x is plenty

 

[PhreeByrd]

Seems a lot more complicated than it needs to be. Why is simple shimming not going to work? It would be much more accurate than concrete which, unless you use non-shrink grout, is going to shrink as it cures.

 

[davocean]

Seems a lot more complicated than it needs to be. Why is simple shimming not going to work? It would be much more accurate than concrete which, unless you use non-shrink grout, is going to shrink as it cures.

I thought it was extremely simple, pour crete in, use a board to screed off excess, don't even need masonry tools or anything.

I'm not sure what you are talking about w/ grout, none needed, it's not tile or blocks

 

[PhreeByrd]

OK. Let us know how simple it is after you've created a rectangular form that's perfectly straight, smooth, and level. I assume you have a high-quality table saw available to use, as well as a jointer.
If you really can accomplish that, then you've already created far more than is really necessary to level the tank.
Also, please do let us know how nice it turns out without any concrete finishing tools.

As for non-shrink grout, Google is your friend.
https://en.wikipedia.org/wiki/Non-shrink_grout

 

[jjflounder1]

Seems a lot more complicated than it needs to be. Why is simple shimming not going to work? It would be much more accurate than concrete which, unless you use non-shrink grout, is going to shrink as it cures.

Obviously you didn't read the whole thread

 

[davocean]

OK. Let us know how simple it is after you've created a rectangular form that's perfectly straight, smooth, and level. I assume you have a high-quality table saw available to use, as well as a jointer.
If you really can accomplish that, then you've already created far more than is really necessary to level the tank.
Also, please do let us know how nice it turns out without any concrete finishing tools.

As for non-shrink grout, Google is your friend.
https://en.wikipedia.org/wiki/Non-shrink_grout

I used a skillsaw, and a screw gun, a hoe and a tub, oh and a level, that is all.
I do not even own a jointer, and the table saw I have is a portable that fits in my truck, nothing special, but it was not used for this.

If you DID actually read this thread/my post, w/ my build link right there showing, you'd realize it was nothing.
You don't even need to be good at ripping form boards, make it close, shim if needed where needed, there's plastic down so crete will not leak out or anything even if there are gaps.

Believe me, if I wanted to show off technical skills, I have pics of that too, but serves no purpose here, just trying to help Op

 

[PhreeByrd]

Obviously you didn't read the whole thread

Uh, no. I read it all. Obviously.

 

[PhreeByrd]

I used a skillsaw, and a screw gun, a hoe and a tub, oh and a level, that is all.
I do not even own a jointer, and the table saw I have is a portable that fits in my truck, nothing special, but it was not used for this.

If you DID actually read this thread/my post, w/ my build link right there showing, you'd realize it was nothing.
You don't even need to be good at ripping form boards, make it close, shim if needed where needed, there's plastic down so crete will not leak out or anything even if there are gaps.

Oh. And I thought, from reading THE WHOLE THREAD, that shimming was not an option for some reason.

 

[davocean]

Oh. And I thought, from reading THE WHOLE THREAD, that shimming was not an option for some reason.

Don't know what made you think that, basically redfish's suggestion is basically a long shim out of a 2x4, and I just showed my version of that w/ my add to it in how I handled my own personal issue, and w/out any voids, and I happened to get lucky and not need any shims under tank as this came out level, but from memory I did add a couple shims at form boards so I could just screed off the excess crete w/out much effort, but it was not 2" worth of shims which would be kinda goofy IMO

I'll save you the click, here's that fancy shmancy high tech pad!lol

 

[davocean]

And BTW, this was all done right there in my living room, no big thing, and when I moved I simply pulled the slab up, wheeled it outside, broke in some pieces and tossed in trash, no harm to floor.

My only mention to shims, yeah, they work fine, probably 99% of us have shims under our tanks, but when we get like 2" out of level, that's a ton of shims, especially if you spread every 6", and they can possibly slip or move around, and you can only do perimeter, so there's a huge void under tank, and anything that should have bottom support(non trimmed tanks) is just not the best idea IMO

 

[jjflounder1]

Nice job [emoji106]

 

[Reefcowboy]

I had to rip my new floors before I set the tank. I would never bet tousands of dollars spent in a system plus risking my house getting saltwater down its walls because of some $5 wood shims.

Start it right and enjoy the tank as it should be. A slight unleveled stand frame can lead to failure a few years later.

I used liquid leveling compound, and was amazed how easy it was and how level the floor ends up. Mix it pour it where the tank will go and in 2 hours its dry ready to go