What’s the best option for leveling the ground under a pool, when the soil is heavy clay? I mean I have a tiller, so theoretically I could till the area and dig that out? Don’t holler at me, but our pools have never been level. I’m moving the one we have this year to another spot and I want it to be nice and right and permenant for at least 3 years. My arms are sore just thinking about the future. Lol
Level on clay soil
- Thread starter Jackiedavis87
- Start date
Also I have access to pea gravel by the yard, so I can use that as a base once level correct?
thefloatqueen
Bronze Supporter
Following this post because I am in the same situation lol. Hopefully someone can help us out! 
- Jun 22, 2014
- 48,011
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
I can relate to the clay. Very frustrating here as well. Seeing as that you have equipment, cutting down a bit might be a great option, not just for the base but to avert the stubborn nutgrass and such we get. Then spray an herbicide killer and/or place a liner down for future weeds. And yes, some folks use pea gravel as it tends to gel together better and create a firmer/tighter base. You see others use sand, but depending on the soil and moment around/under the pool, sand can begin to seep-out (or down through cracks) and become useless. Once you have the pea gravel down, you can still toss some insulation pads, Gorilla pads, or something to go between that and the liner if you want that extra cushion for your feet. Hope that helps.
We have the clay soil also. When installing my pool I used a sod cutter to get the ground as close as possible to level and then dug down to level the pavers and then used DG Decomposed Granite to level back the inside ground. Check out my build thread in my signature. I don't know how well the pea gravel will work to level the ground, you can't compact the pea gravel and I think it will be washy when you walk on it. You want something that will compact, DG, crusher dust etc.
I moved my pool this year and used the tiller and shovel to get things level. I only have a 12 foot intex though, so not too bad, but bad enough that when I finally upgrade to a bigger pool, I'm hiring it out!
Having a sod cutter could make that clay work like butter.. unfortunately I only rented it to actually cut the sod and am not able/ willing to spend the money to rent it again. I have been using a pickaxe and shovel. I have found that spraying the clay down until it puddles about 30 minutes before working on it helps it not feel like I'm chopping and digging into solid brick. I considered the tiller because my brother has one but from the times I have used it in the past it seemed to hop around a bunch when it hit a hard spot and keeping the depth controlled was also a bit hard. If you have the money hiring out or renting a skidsteer would definitely be the way to go, unless you have a team with shovels this is no fun!
Howdy neighbor!
Lol that’s what I’m worried about. This pool is 24’. I rolled the tiller out yesterday, but the gas is going to have to be drained. So project awaits.
CJadamec
TFP Expert
A neighbor with a nice garden tractor might be able to make breaking up the soil easier. Some places rent them.
A little tractor like that can level a pool sized area in a couple hours.
A little tractor like that can level a pool sized area in a couple hours.
The sod cutter did good on the soil that wasn't like a rock, It helped a good bit but couldn't use it for everything. I did have a lot of pick ax time also. And you are correct with the water, I would go out and saturate the ground a couple times a night so it would help the next day to soften it up some.
Wobblerlorri
Bronze Supporter
- Apr 16, 2019
- 2,010
- Pool Size
- 4024
- Surface
- Vinyl
- Chlorine
- Liquid Chlorine
We have clay soil, but we lucked out -- I had had a garden in the same spot some 8 years ago, so the ground had compacted into a nice level area. We used a tiller to tear up the sod, raked it out, then used the board and level method to even out the area. I was able to use a hoe and a garden trowel to dig out the uneven areas.
Clay is tough, but it's doable.
Clay is tough, but it's doable.
In my case it seems to stay generally level but the cracking may present another issue. Getting it smooth is another story, unless it it real wet it tends to come up in clumps which makes keeping it smooth a pain.
Well I’m going to be a terrible TFPer and uhhh, I ordered 2 dump trucks of foundation sand and I’m building a house pad for my pool lol.
- Jun 22, 2014
- 48,011
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
I totally understand the cracking and clump spaces in the clay. Hopefully the foundation sand you ordered will retain enough firmness to fill those voids.
Well I’m not filling the voids exactly, I’m going to build the entire area up. I’ll get a pic up when it’s done, but that will probably be another week lol.
I would suggest that you use a material that will compact and rent a plate compactor if you plan to build the area up. Sand won't compact and your legs cold sink and have a big mess.
I used DG to build up under my pool and it has been solid as can be.
CJadamec
TFP Expert
You want compactable fill for a pool base. Something like road base, quarry process, or crusher run material (it's called different things in different places).
The reason you use compactable fill is that once you compact it properly it will for a very hard and stable substrate.
It's not against TFP to make a base for a pool it's just not recommended because it takes expensive equipment to make a base, and the fill adds a lot of cost. My pool is up 6 inches on a compacted base. It easily added 1k to my install and I did all the labor. There are a couple pictures of how I made the base in the link in my signature.
The reason you use compactable fill is that once you compact it properly it will for a very hard and stable substrate.
It's not against TFP to make a base for a pool it's just not recommended because it takes expensive equipment to make a base, and the fill adds a lot of cost. My pool is up 6 inches on a compacted base. It easily added 1k to my install and I did all the labor. There are a couple pictures of how I made the base in the link in my signature.