Prevent Liner Float

[Shirker]

I saw this post but did not want to hijack the thread. Are there good precautions to prevent a liner from floating? Our build site is very rich in hard clay but we are on the top of a decent sized hill and it will be relatively easy to drain surface water away from the pool. Should I consider digging a well near the pool that would allow me to pump water out? Or is it just surface water I need to be concerned about with clay soil?

Thanks in advance!

 

[JoyfulNoise]

How is the pool being constructed, walls and floor?

If you expect high ground water, then dry well with a submersible pump would be best. You could also add buried drainage pipe around the structure along with the dry well to help move the water. Expect to pay more for all those extras.

Clay soil tends to hold water and cause expansion and contraction unlike sandy soil that allows water to build up and flow through it. Did your PB have a soil report done? That usually requires a few soil cores to be taken and sent to an analysis lab. Do you have any county or city engineering records for your area? Flood maps or geological information? That type of info helps you to know what to expect in terms of ground water movement and how close to the surface it gets.

 

[Shirker]

We haven't gotten that far with the PB yet. He has given us rough estimates based on our ideas but probably at least another month or two out for full build plan. We do have soil test reports from our house construction & septic install from last year. We are not in a flood area.

I'm not sure how high our water table is but when they drilled our drinking water well, we hit bedrock at 88 feet. Stopped at 260 feet with a flow of 31 gpm.

 

[JoyfulNoise]

So liners float when water pushes upward from beneath the pool where the upward forces counteract the downward pressure of the water in the pool that’s above the ground water line. So you don’t necessarily need ground up to the coping for it to happen. The level at which the forces balance out depends on pool shape. But it also sounds like you are more in danger of surface run-off issues rather than ground water infiltration. If the pool is on a slope at a higher elevation, then some basic buried drainage should be able to handle water flow around the pool. A dry well would be unnecessary.

Depending on the construction of the walls and base, you might consider having the PB build the pool with compacted gravel fill all around the pool to help with drainage.

I think the discussion is mostly conjecture at this point until you get some finalized plans and a build schedule.

 

[pabeader]

Be sure to post your quotes before you sign anything. There are a number of folks around this place that will be very happy to help out with the stuff you need and don't need from the list.

 

[jimmythegreek]

Im halfway thru my build and in high ground water country. I added 3 7'deep well points that I have sumppumps in set automatically and I have 4" sch40 perf drainage pipe on top of my footing around the whole pool that dumps into the well points. I cant tell you how many rainstorms we've had here in NJ the past 2 months where they ran for 20min straight. make sure if you do any of this you use clean stone and have filter fabric around all the stone NOT just the pipe as it will eventually clog the stone w silt from the clay. I wrapped all mine in septic filter fabric all the way around and same with well points 4' diameter around the 10" vertical pipe. took a day at most and is cheap insurance in my book. find out if you even have high water table if not dont worry about it maybe a single well point by deep end just in case 1 hr job

 

[Shirker]

Thanks, guys. Once I have a quote, I will be sure to post it.