How out of level can a hot tub be?


Old 05-08-19, 05:12 AM
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How out of level can a hot tub be?

When my concrete pad was poured for my hot tub, they poured it with a slight slope away from the house for water drainage. Will this cause issues with my spa? The spa was delivered and hooked up yesterday and I filled it last night. I've found that on the 7' hot tub, just looking at the top jets, that once my water hits the top of the jet on the high side, it's about 1/2" higher on the low side.

Looking at this water height difference leads me to believe that my slope is .07" per foot. At worst, it may be .14" per foot. This of course is also hoping that the jets are the same height on the tub. Thoughts?

If I need to level it out, are there shims that can be placed under it that are stable enough? I was thinking that if I'm a 1/2" low, I could toss a sheet of plywood under the box on the low end, but I want to avoid stressing out the shell.

I should also mention that there was a hot tub on this concrete pad prior to us owning the house.
Old 05-08-19, 05:31 AM
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Out of level isn't a big deal. The worst thing is cosmetic that you might be able to see that the water is not parallel with the top of the spa. Having the slab flat is more important however. A flat slab will evenly support the bottom of the spa. If the slab is not flat then parts of the spa might be unsupported then all the weight of the water can twist or put stress on the hot tub.

Almost anything solid can be used as a shim. For a spa that will be in place a long time I would use scraps of metal. They can be gotten from any welding shop or metal fabricator from their scrap pile. Also, most home centers sell aluminum and steel. You can also use things like shingles or sheets of plastic. I don't like to use store bought shims as they are rather small and light. One little touch when placing the spa can knock them out of position but you can glue them to the bottom of the spa with caulk or construction adhesive. Then tip the spa down into position.
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Old 05-08-19, 05:55 AM
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Well slab is certainly flat. I checked that with a flat 2x4 before placing the tub there. It's just that the slab has the typical slope seen to direct water away from the house. I was also able to get the water above all the jets just fine, and the water just creeps to below one of my pillows on the low end.
Old 05-08-19, 09:18 AM
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If they knew it was for hot tub they should not have sloped, I just had one installed last summer and they did a great job.

Having the level off by 1/2" is not going to be an issue other than the jets at the very top may generate more bubbles on the high side.

I would not shim, there is a lot of weight in the tub and would just keep it flat to the slab for support!

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