Next point - tank levelling

[Aquattro]

So I've built the stand, it's big and heavy, and it sits right across a hump in the floor (almost an inch play side to side). At 2500 pounds, am I ok to use wooden shims on the corners (can't reach back edge once in place) or should I look at great levelling?
I thought of framing in the area and pouring some quick set on plastic to create a mini slab, but that might crack at the edges and be bad....

thoughts?

[Delphinus]

I sure hope wooden shims will suffice. Although what I did on the low side was cut a 2x4 to the width needed and slid that under the 2x4 that was at the bottom of the stand. It was the middle that proved to be a challenge because it was a triangular gap now, so I just jammed a whole lot of shims in the middle under the centre vertical post until they were one solid mass, then I chopped off the bits that hung out from under the stand, and then I encased that in silicone on the tank side and Great Stuff on the outside - those shims are not moving anywhere anytime soon.

I believe Michika used some kind of levelling compound. I would suspect because of the edge cracking you mention, that if you went that route that you have to do an area larger than the tank stand so that the stand is not sitting anywhere near the edges.

But I'm no builder so what do I know..

[andestang]

Given the chance I would level the area properly with some self leveling mortar.

[golf nut]

Originally Posted by Aquattro

So I've built the stand, it's big and heavy, and it sits right across a hump in the floor (almost an inch play side to side). At 2500 pounds, am I ok to use wooden shims on the corners (can't reach back edge once in place) or should I look at great levelling?
I thought of framing in the area and pouring some quick set on plastic to create a mini slab, but that might crack at the edges and be bad....

thoughts?

Really depends on the type of stand you have built, got pics?

[MitchM]

It does depend on the stand construction, but also on the floor.
I am assuming that this is an older home with maybe douglas fir floor joists, a 3/4" subfloor and 3/4" hardwood flooring material.
Is the hump from the subfloor and floor finish material? Or is the hump from a crown in the floor joist? Is the hump stable? Does it creak if you stand or jump on it? If the hump isn't stable, anything you pour on it now will surely crack once weight is put on it.
If the hump is from the hardwood flooring and subfloor only, the tank setup may level itself.
If the hump is from a floor joist, then even 2500 lbs won't straighten that out and you will need to shim.
If the stand is built with bottom plates on edge, then you could be fine with relying on 3 points of support - the hump plus shimming on each end.
If the the stand is built with bottom plates on flat, then shimming in numerous places under the stand would be recommended.

Lots of "if's". Pics of the stand, floor area from above and below would help. Hopefully you can see the underside of the floor from the basement.

Mitch

[wickedfrags]

Exactly my thoughts. Get it perfect.

Originally Posted by andestang

Given the chance I would level the area properly with some self leveling mortar.

[sphelps]

Rather than having a stand with a flat base or lengthwise beams as a base add four legs, one at each corner. This makes leveling much easier. The legs don't have to be anything overly tall, just high enough to clear the uneven surface, even some of those furniture pads for hardwood floors can work well.

[Aquattro]

Originally Posted by MitchM

It does depend on the stand construction, but also on the floor.
I am assuming that this is an older home with maybe douglas fir floor joists, a 3/4" subfloor and 3/4" hardwood flooring material.
Is the hump from the subfloor and floor finish material? Or is the hump from a crown in the floor joist? Is the hump stable? Does it creak if you stand or jump on it? If the hump isn't stable, anything you pour on it now will surely crack once weight is put on it.
If the hump is from the hardwood flooring and subfloor only, the tank setup may level itself.
If the hump is from a floor joist, then even 2500 lbs won't straighten that out and you will need to shim.
If the stand is built with bottom plates on edge, then you could be fine with relying on 3 points of support - the hump plus shimming on each end.
If the the stand is built with bottom plates on flat, then shimming in numerous places under the stand would be recommended.

Lots of "if's". Pics of the stand, floor area from above and below would help. Hopefully you can see the underside of the floor from the basement.

Mitch

Older home, no idea what type of construction (finished basement with tenant). Hump is pretty solid, assuming due to settling and such. Hump is simply part of a wave that spans the room, but solid, no squeaks or movement. Stand is 2x4 construction, bottom plates on edge, although bottom skinned with 1/2" ply. I have a wall below the tank with a framed closet, so pretty sure joists won't sag under weight.

[MitchM]

Finished floor...wood, tile, lino..?

Mitch

[Aquattro]

Originally Posted by MitchM

Finished floor...wood, tile, lino..?

Mitch

Laminate over basic foam underlay.