csdude55 Posted September 22, 2023 Report Share Posted September 22, 2023 When I bought my house it had a hot tub on a cement slab. I could tell that it wasn't quite level, though, which I HOPED was due to the fact that there was a wet and rotted piece of plywood underneath! Today I had a new hot tub installed, and... I was wrong. The cement slab isn't level 😕 I'd bet pennies to dollars that they didn't put gravel or anything underneath, they just poured it straight on the ground. Obviously the right move would be to jackhammer the old slab out and have it done right, but I honestly don't have the money to do it. So I'm thinking... less expensive. I'm thinking that I can drain the hot tub, lift it up, then put a frame around the cement slab and add pea gravel or leveling sand to level it up. Thoughts? If that's acceptable, how do I lower the 500lb hot tub on top of the freshly leveled sand without messing it up? Quote Link to comment Share on other sites More sharing options...
CanadianSpaTech Posted September 22, 2023 Report Share Posted September 22, 2023 How far out of level? Post some pics of the area so we can see what you are dealing with. Quote Link to comment Share on other sites More sharing options...
Cusser Posted September 22, 2023 Report Share Posted September 22, 2023 8 hours ago, csdude55 said: When I bought my house it had a hot tub on a cement slab. I could tell that it wasn't quite level, though, which I HOPED was due to the fact that there was a wet and rotted piece of plywood underneath! Today I had a new hot tub installed, and... I was wrong. The cement slab isn't level 😕 I'd bet pennies to dollars that they didn't put gravel or anything underneath, they just poured it straight on the ground.  My house was built in 1979. I bought it in mid-1988. In fall 1988, I had my spa installed on the patio concrete slab (you have concrete, not cement; cement + sand + gravel makes concrete). Well my patio is not perfectly level, and I can tell that the water level is different on one side as opposed to the other. It just doesn't bother me, and the spa from 1988 is still operating !  Quote Link to comment Share on other sites More sharing options...
RDspaguy Posted September 22, 2023 Report Share Posted September 22, 2023 Flat is more important than level. Not flat will destroy your spa, while not level is usually just a visual irritation. Consider that your spa holds somewhere around 400 gallons of water, at about 8lbs per gallon. So, a ton and a half of water, give or take, on top of the spa weight. And you want to frame it with a couple inches of pine and backfill with sand, which acts much like a liquid under pressure? At least use concrete. Quote Link to comment Share on other sites More sharing options...
ratchett Posted September 25, 2023 Report Share Posted September 25, 2023 Hot tub engineers are not dumb. They know most poured concrete slabs are not level due to drainage.  As mentioned, flat is important because that's what distributes the weight evenly. Pay attention to the jets in your spa - are they higher on one side of the spa than the other side? You want the side with the highest underwater jets on the LOWEST side of the pad. That way you can fill your spa adequately without the need to over-fill. Quote Link to comment Share on other sites More sharing options...
cranbiz Posted September 25, 2023 Report Share Posted September 25, 2023 My pad is also not level but it is perfectly flat. It's not off much though. If it's like cusser's tub, you are fine. I'm off about the same, it's not an issue. 1 Quote Link to comment Share on other sites More sharing options...
csdude55 Posted October 10, 2023 Author Report Share Posted October 10, 2023 Sorry for the late reply! I just now found the emails in my spam folder, I didn't know anyone had replied 😕 I'm including a pic from above, you can see the water level on the right versus left. I had another pic that showed it more clearly, but I keep getting an error while uploading it 😕 I'm also including 4 pics, showing the level on each side. The side with the control pad is the most out of level, and the opposite side is the next worst.  Quote Link to comment Share on other sites More sharing options...
creoleswift Posted October 11, 2023 Report Share Posted October 11, 2023 Honestly what I did to my buddies was I jacked it up put sand underneath it you can use filler sand or anything really and it looks like you're off by about a half a dude so I would use the half inch by 12 square pavers pavers in the most unlevel but in this case you need to make sure you have enough sand under the whole thing to keep it even all the way through so it's a job and half I highly doubt you can pull that Jacuzzi out easily to get under there to pour enough sand because if you raise one side the middle is going to be not touching ground it's honestly an annoyance in your case Case if it's not bogging down your pump or anything I wouldn't even touch it to be honest Quote Link to comment Share on other sites More sharing options...
CanadianSpaTech Posted October 11, 2023 Report Share Posted October 11, 2023 Level the spa on blocks and use roofing shingles feathered out from low to high making sure the base is supported evenly. Have used rigid foam board insulation as well that is available in different thicknesses again making sure the spa is supported evenly side to side and front to back. Usually shave the first board to fit as a wedge. Whatever you do make sure the foot well has proper support and as mentioned flat and even is key. Quote Link to comment Share on other sites More sharing options...
Nate Lee Posted October 21, 2023 Report Share Posted October 21, 2023 Maybe you could try shimming. I have heard multiple cases where people successfully leveled their hot tubs with pressure treated wood shims. Quote Link to comment Share on other sites More sharing options...
cranbiz Posted October 23, 2023 Report Share Posted October 23, 2023 On 10/21/2023 at 9:00 AM, Nate Lee said: Maybe you could try shimming. I have heard multiple cases where people successfully leveled their hot tubs with pressure treated wood shims. Bad advice. The bottom of the tub needs to be fully supported when full of water. Shims will not fully support the tub with the weight of water in it. Using the methods that @CanadianSpaTech described will allow one to level the tub and keep the bottom sully supported. Quote Link to comment Share on other sites More sharing options...
csdude55 Posted October 23, 2023 Author Report Share Posted October 23, 2023 Thanks for all of the advice! I'm running out of time and it's about to be cold weather, so this will probably be pushed off until April 😕 I hate that because it's physically uncomfortable the way it is, but there's just not enough time in the day! Quote Link to comment Share on other sites More sharing options...
Dozerman Posted October 24, 2023 Report Share Posted October 24, 2023 The very best, permanent solution would be to jack the tub up (after draining it) and get some lumber to build forms around the top of the existing slab. Use self-leveling concrete floor leveling compound to make the slab level. It looks just like cement powder but you mix it really thin so if flows level on its own. Once it cures, overnight is long enough, I would add a layer of Styrofoam insulation on top of the cement before lowering the tub. Optional but it will eliminate any stress points under the tub frame and ensure equal weight distribution. Â This is probably overkill and any of the above suggestions would likely do it for you, but this is the way I would do it. Quote Link to comment Share on other sites More sharing options...
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