Planning work for 12 x 24 semi inground on a sloped lot

Novak77

Member
Mar 18, 2021
22
Santa Cruz, CA
So, I now have my pump, SWG and filter... and the pool is on the way from the pool factory!! Thankyou to forum users for advice on these purchases.

I’m about to start prepping for this which will be a big job, and take a few months. I’m going to try and enjoy the journey (we’ll see if I’m still smiling in a few months...)

I have a ‘difficult site’. In the area I’m planning on installing the pool I have a 1:4.3 or 13.5 degree slope. Basically it’s going to suck. I’ve been measuring and planning and think I do have a game plan for this, but wanted to get some input and ideas from this forum to make sure I’m not missing any gotchas here... I want to do this right. Once😂

Once I have the first stage done, I may get a professional leveling and install for the pool itself, or may just take my time to get things properly level. For general earth moving and retaining walls, I have some guys to help me. I’m pretty sure I’ll be able to find a place for all the excavated dirt with the planned retaining wall etc. I currently own a plate compactor from a previous retaining wall project.

I’ve sketched out my plan below it 4 main phases:
  1. compact excavator to dig out dirt to create a level area and drop the grade to 26” which is the max depth I can put the pool in ground. Here I will also level off the ground for 3’ outwards to try and minimize additional forces on the sidewall. I’ll put railroad ties/rebar there to act as a cheap and dirty retaining structure between the pool and the retaining wall I’ll later build. I will be digging out more than I need to install a French drain here also.
  2. The excavated dirt will be piled against the existing retaining wall (I may run a backup leach field for my septic at this time but this doesn’t affect the pool plans). Leveling can now begin and pool install can be completed. I’ll out a temporary but code compliant electrical outlet and filter, pump etc on pavers until I later move these into the shed. ( kids can start using the pool!)
  3. New retaining wall will be built, previously excavated soil moved downhill to backfill and compact
  4. Build deck ( deck may well end up smaller than shown due to current redwood prices!!)
Does anyone see any major issues or gotchas with this plan? I think my main worries are stability of the soil in the region of the pool at the bottom end?

Any and all advice appreciated!

Thank-you,

Novak
 

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Wow, that is a tough site, but you can do it! I’m a flat lander here in FL so I will let others comment on your slope plans. Congrats on getting your order in!

i think @Mdragger88 has quite a slope in backyard as well!
 
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That’s alot of slope! Mine is not quite as bad & i also had plenty of room to grade things down around the pool. Will this pool have the stabilizers that are buried? It looks like they will come very close to the fence. I think I would get an opinion from a professional landscaper/ dirt/ drainage type person to be sure you aren’t creating any issues
 
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That’s alot of slope! Mine is not quite as bad & i also had plenty of room to grade things down around the pool. Will this pool have the stabilizers that are buried? It looks like they will come very close to the fence. I think I would get an opinion from a professional landscaper/ dirt/ drainage type person to be sure you aren’t creating any issues
Thankyou for the reply!

I can probably move it another foot or so from the fence with no problems. Currently I’m planning on the waterline being 6 feet away, and the edge of the structure about 5 feet away. I don’t *think* there are buried stabilizers. There are buried straps between the straight edges of the pool.

that’s a good idea to check in with a landscaper on whether this will cause any issues I’m not considering here. I will do this.
 
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So there is now a change in plan after talking with a few guys I know about this and also reading this thread which did what I want to do on a more extreme slope,

Newbie: AGP Install on Steep Slope (MN)

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Bottom wall is already in progress...

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Unfortunately it does mean I need to build up an area to 2 feet maximum. From reading the above thread, and talking to a few people this can be done so long as the infill material is good clean dirt, it’s compacted with a few passes of a plate compactor every 4 inches, spayed down a lot over night and compacted again. I’ll use 2 layers of geo grid soil stabilizer for the wall at the bottom and keep the main surcharge 3 feet away from the wall. Being a fan of over engineering, i may top it with 6 inches of compacted class 5 material.

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My concern is now going to be if I’d do use the compacted class 5 layer, how I bury the straight wall footings and stabilizers in this material, as well as the 2 “ blocks for the footings of the round sections.

I’m thinking the easiest way will be to:

  1. lay down 2 inches of class 5, level and compact.
  2. Position and level blocks for the straight side supports
  3. Add 2 more inches of class 5 and compress to get to the level of the top of the blocks
  4. Position and level the straight side support footings and the curved side support blocks
  5. Add, level and compact 2 more inches of the class five
  6. Add the stabilizer plates
  7. Use 1” of sand to level over the stabilizer plates


Alternatively, the whole 6 inches of class 5 would be put down and then dug out for the blocks etc... initial thoughts are that this would be harder?

does anyone have any experience in putting an oval on compacted rock?
 
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Compacted rock is the way to go over dirt. You'll get a better base than with soil.
 
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More progress this week. lower wall is finished, back filled and compressed. Currently have a sprinkler on it to help any further settling.

next is finishing fully digging out the pad. I decided to put a retaining wall at the back as well so it won‘t be inground at all. Seemed like a bad idea considering the severity of the slope.

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