Pool Repair Question

And my wife wonders why I refuse to hire 'pros' to have work done around the house.

If you want something done fast, hire a pro.

If you want it done right, do it yourself.

He needs to dig a trench along the side of the pool, starting at the deep end about 2ft deeper than the deepest pool bottom level, run a 1.5" pvc line with a basket strainer on the end, to a pump and min. 50' discharge line, cover the pvc line with gravel and pump out the water....Now dig out the deep end of the pool from underneath and allow the pool to level by blocking the bottom drain and filling the pool with just enough water to level the pool, then dig down to the pool drain location from underneath and replace the line and fittings...

PS: Get a backhoe...

The floating of the pool and any subsequent attempts to secure it back in its original position create a likelihood of additional damage.

The original leak will not be the only problem. The additional problems will probably not be easy to locate immediately and might even take a while to show symptoms.

Any fix is unlikely to be both cheap and reliable. The homeowner should consider talking to an attorney about recovering costs from the at-fault contractor.

Demolition and building a new pool is probably going to end up being the ultimate solution. The number of lesser fixes endured prior to complete demolition and building a new pool will create the major variance in total repair costs.

An area I know where they had the same problem with ‘septic tanks’, they had to put a cement slab over it, to keep it from floating up...

Are you suggesting putting a cement slab over an in-ground pool? I wouldn't want to be the guy on the high dive!

Nah... I mean sure.

with a high water table... the problems that the OP is having now, should have been worked out before the pool was put in or suggested not to put in a pool. Nice thing about hindsight, huh?

The high water table is common in the Houston area and pool contractors are experienced with working around it.

My friend that told me about this problem also has a pool. He has had work done on his pool and the procedure was to bore a couple of holes in the bottom to let the water migrate into the pool, then use a pump to keep it dry while repairs are made. When the work is finished, concrete and plaster are used to fill the holes and water is added.

I suppose you could drill a couple of shallow holes around the perimeter of the pool and pump the water out, but they drilled holes directly in the bottom of his pool and it worked.

Depending on the permeability at a particular location, as well as the depth of the water table relative to the depth of the pool, a sizeable pump might be required. If holes were drilled in the pool and the pump kept the pool close to empty, the local water table would need to be drawn down sufficiently to avoid the possibility of the pool popping out.

Seems like a better solution would be to line the bottom of the pool with sand bags as the water level is brought down so that no holes need to be drilled and the pool is not unloaded and so does not experience significant movement.

I don't know how they do it over there, but here in Australia all inground pools have a hydrostatic valve fitted at the deepest point of the pool to prevent this very occurrence.

The valve opens to let water into the pool from the outside if there is excess pressure out there.

If pools are installed where there is lower ground somewhere nearby, then a drain pipe is often installed from under the pool at the deep end to an above ground point lower than that.

If there is no lower ground, then a breather pipe is installed from under the deep end to ground level, any build up of water will then be discharged from the pipe and will not float the pool.

All hind sight in your case unfortunately, but perhaps the building codes need to be revisited.

Yep. Walk away.

What you have is the equivalent of a concrete/fiberglass/other(?) pool trying to float like a boat on the surface of the high water table.

First, Figure out what the volume of water which the pool holds.

Figure out how much that water would weigh.

Figure out how much (concrete/concrete-slurry/other-material) would equal the weight of that much water.

This is the tricky part.

Figure out how to attach that much (concrete) to the pool sides-and/or-bottom, so that the concreted-pool will act as a single structure that would rise or sink as if it were a single (boat). This should provide a substantial margin-of-safety against future water-table rises greater than the 6-inch rise mentioned. (cConcrete floor slabs that have become out-of-level have been completely re-leveled using this technique.)

Pour the concrete, and wait twenty eight days for it to sufficiently cure.

If the pool has not risen, then fill the pool with water, etc.

P.S. You might need a some kind of a Permit to do such work...

My first question is who and how was the pool originally installed? Why did the water table rise? If this was installed during low tide during a drought then a cofferdam maybe the only approach that will work.

Assuming this is a fiberglass shell, I expect the shell is now damaged at multiple points and may no longer be repairable. Remove the damaged pool and install a new above ground pool after mitigating the location with clean back fill.

You will need

Or to get rid of the pressure of the water table with pump(s)

Or release the pressure into the pool with a 2" drilled hole and plaster with under water curing cement mix - Allow to harden and plug the hole somewhat deeper and plaster that part also.

Empty the pool

Finish

I'm sorry to have not read the post well enough.

I only dealt with pools that had the liner and/or mosaic come loose from the fundamental box form.

If it is really the whole pool that is starting to float then there is a serious structural problem. The pools we have installed just next to canals or beach with low water table have been designed to withstand the upwards force by putting an enormous floor plate read too big in surface and way too big in weight with reinforcement.

The walls are connected with reinforced steel rebar and mesh to the floor and around the pool a lot of fill is also loaded on that base plate. In extreme situations we also stabilized the surrounding mass around the pool with a mix of cement pea rock, sand and rocks.

Once you have a high water table, your pool is like a ship, made of concrete that wants to float. When the water is in the pool it is more like a submarine but when the pool is moving up so easily it is a misfit.

One of the posters suggested to pour an extra floor which can help when the rest of the pool is sound. Consider to raise it up higher and use archimedes' law to calculate your floating situation and use your common sense to not leave the pool empty for too long of a time.

If the pool is made with gunite changes are low that it is strong enough to play.

The excavator is a next step

Friend,

You now have broken pipe fittings below the pool from the main drain to the pump, as well as broken pipe fittings alongside the pool from the filter to the skimmer(s). In addition, the pool is no longer level. I know of no way to reliably fix it. When the pool gets filled you will probably find the deep end settling back down a few inches because is no longer supported by solid fill.

There are expensive ways to replace the broken pipes, but the lack of foundation integrity suggests that any of these would be futile. You could hire a plumber with a small camera and have it inserted into the main drain pipe to locate any cracks or breaks--this is fairly inexpensive and very instructive.

The original fault was in the pool's installation. It should have had one or more hydrostatic relief valves installed within the deep end main drain, so when the subsurface water pressure exceeded the pool's water level (when the pool is pumped out or drained), the subsurface water would go into the pool. These have been around and specified for pool installations for over 30 years.

New pool time, along with a probable visit to a lawyer.

Sorry, JMM

What Solar Eagle said (#2) is correct but it only fixes half the problem.
When a pool is in high water table areas it is wise to put a relief valve, depending on the pool size maybe a couple, in the bottom, so that when the pool is emptied for whatever reason, the valves will pop open and the pore pressure will relieve.
The inflow can always be pumped out during and at the end of the repairs/cleaning, but the structure remains intact.

What you have here is a Humpty-Dumpty type situation

A perfect seamless repair is nearly impossible at this point in time.

I say nearly,but not impossible if money is not object.

If the friend is uber-rich,no problem.

I am sure there are unseen damages that will not become evident till much later.,and it will become a migraine for years to come.

All I can advise is to consult a local code authority to see if the original installation conformed to local codes.

If not conformal,see a lawyer about a claim against the original installer.

If the original installation was done to code,then the repair contractor did not perform due diligence when repairing the leak.

He should have dug a french drain around the outside of the pool and installed a pump .

You may get lucky when refilling the pool,but I suspect the sides of the earthen walls have subsided into the hole below the pool,and it will never properly seat into the original bed.

The plumbing is also very likely to be damaged.

The drain is usually in the deepest part of the pool,and this is where the rise is greatest.

IMHO: An in-ground pool is a bad choice.It is like a dependent that never leaves home,requiring monthly expenditure for upkeep,chemicals,power to pumps,covers in the winter,etc.

I had one,and after the kids and grand kids grew up and moved away,it was seldom used.

I filled it in,put a covered garage over the spot, bought a rowing machine,and have no regrets.Saved hundreds of dollars per year in expenses:chemicals,power,headaches.

A neighbor put in a nice above ground pool,and when he had no more use for it,it was disassembled and sent to the landfill..as the saying goes,hindsight is 20-20.

Fill it up with building material, put a slab on top and build a new pool with deck on the slab and surrounding area . Sit back and count the money you saved and praise yourself on a job well done. Promise you will not happen again.

Houston, being somewhat near the Gulf Coast, I have to ask how vulnerable is it to typhoon seaon flooding?

You have the wrong location. Houston experiences hurricanes, not typhoons.

Hurricanes are the preferred term, but we are worldwide multicultural here, so media uses typhoons, cyclones and hurricanes interchangeably to cover all cultural demographics.

Tropical weather is the big nature evil here. Typhoons = cyclones = hurricanes, tropical storms (no defined rotational center), and tropical waves (big radar blobs filled with water) are the bane of our existence. Simply said it can flood here just about any day of the year. (2) 500-yr storms and (1) 1000-yr storm in the past 10 years. Whoopsie on the predictive statistics and models.

Wow! That is some pretty serious wetness, there...

A Q₂₀, Q₅₀, or Q₁₀₀ would be bad enough, but what you're talkin' about is statistically astonishing...

Connecting pipes are gonna have to be on some-kinda (pipe-steriods?) to hold down a pool under typhoon-type weather like that!

our problem:

1. is we are pancake flat
2. our drainage capacity NEVER was enough even before development; when people refer to Houston as swamp they are historically correct.
3. flooding is mitigated by a retention system built in 1935 and drained by 1960's trenched, widened, straightened, and channelized bayous; system problem is no one could have for seen a small +/- 150,000 people city becoming the third largest in the USA (sorry Chicago either this or next census you will be 4th)
4. we were forced to open the sluices to the primary mitigation dam mid-storm during the 1000-yr or the hydrostatic pressure was going to crater the 80-yr old earthworks
5. we have been building more retention, BUT we are still 20-30 years behind
6. much of the inner core city has gone from single family with water holding yards to mega multifamily fast draining concrete and hard surface.

So all that means weather that should be a 50-year or 100-year event has a 10x multiplier. It's still an unreal amount of water coming from the sky, but way much of it's affect is our own damn fault.

Connecting pipes do no holding. The weight of the water in the pool does ALL of that, with the pipes just riding along to transport the water between the pool and the filter/pump. That is why you NEVER drain a pool unless you have ensured that the subsurface water level is lower than the pool bottom or that working equalizers are already in place. I have seen a backyard pool after it rose up almost 24" after a heavy rain while it was empty!

The community pool I designed and built had three separate methods for preventing the buildup of subsurface water: 1) equalizer valves in the main drains (hidden from damage and view by the grating), 2) separate drain pipes from the gravel bed under the main drains (going to a place where they would carry any water away by gravity), and 3) footing drains around the pool (bedded in gravel and covered with filter mesh, below the bottom of the pool walls, also draining to the surface by gravity).

--JMM

before deciding how to proceed I would want to use an inspection camera to look underneath everywhere possible .. and use a pencil and paper to make a grid noting the location of anything that is or could be damaged if the pool were able to be reset.

what's below the deepest part is of interest.

If there were no major obstructions and rock, could a hole big enough for a trash pump intake be made at the deep end?

attach the pump and hose.. fill the pool AND the perimeter. sucking out water and debris from underneath.. If I wanted to get creative I'd put some long sturdy boards over the lifted end of the pool and run a vibratory plate compacter over the top as well.

maybe have a long curved power washer pipe on hand as well. ..to run down the side when the pool is full and the pump is pumping slurry..

All very good; in the lab. In the real world here in Houston if a pool moves six inches it stays moved at least 5. You see the coefficient of friction in our very clay soils just "vacuum seals" the pool in to it's new place. You could break this seal by backhoeing the perimeter to the depth you want, but at that point the $$$ delta is so small you might as well jackhammer and start from scratch.

I'm impressed with the interest and good ideas expressed so far, thanks! I will forward them to my buddy down there who is friends with the second contractor.

As it stands right now, the second contractor is planning to leave the pool where it sits and build a new, level deck around it. This sounds rather bizarre to me, and I don't know if he has had any previous experience in fixing this kind of problem. I really don't think anything good can come of this without a massive influx of time and money.

Sounds like the new contractor is more of a carpenter than a pool guy...

You should hire a known professional on that and not just hire any one you find.

You've had a lot of responses to this problem, but none really solve the issue.

There is no way that this pool is going to return to it's original position unaided.

You haven't told us what the construction of the pool is.

I presume that it is not a vinyl lined pool as a float out would be unlikely, the water would generally seep in at the back of the liner and sit on top of the poured floor, which would normally remain in place.

If it's a fibreglass (fiberglass for you lot over there), then you may be able to lift it with a crane and reset and replumb it, of course it's possible that the shell has been damaged by the movement, especially around pipe entry points.

If it's a poured concrete pool, then there is nothing that you can do to fix it economically. If it's fairly large, you might build a smaller one inside the old shell or, as others have suggested, fill it in and go with something else - either way just be sure to put some decent holes in the old shell to stop it rising any further.

Sorry, it's a gunite pool.

It may still be do-able, but only if the bottom edges of the gunite pool walls are very squared-off, and if the maxium highest high-flood-level recorded is not very much higher than the highest elevation of the pool rim. Also, any, and all, conecting piping would have to have appropriate isolation connections added.

In theory, the owner could excavate a full-depth plus at least 1 foot more, trench all around the outside-wall of the still-filled pool that goes at least 1 to 2 feet underneath ythe pool-bottom. ANd, then cast a horizontal slab from the extreme outside of the trench to at least the inside of the pool wall, so as to provide a substantial concrete ''lip'' both over the top edge of the pool wall AND sufficiently under the bottm corners of the pool-bottom, so as to hold the entire pool, top to bottom and 360 degrees all around, type of C-ring of full-density concrete.

In this way, such a concrete-ringed pool could be made heavy enough to adequately resist local uplift forces from rising ground-water levels, what ever their total uplift causes might be.

Going back to a previous post #24: The fact that your friends decided to jackhammer the pool doesn't surprise me. I have known as family, friends or business clients +/- 10 homeowners who have had pools in Houston. At least 3 of them went for jackhammers. Our dancing mobile soil means a constant flow of cracked shells, busted pipes and trashed out flatwork. My stepdaughter & son-in-law are right now faced with +/- $3K of flatwork and exposed shell edge repair.

Oops! Double post. Sorry about that!

I thought that I should report back with the final outcome of this problem.

I was told that the owners decided to scrap the pool. The bottom was broken up and filled it with dirt. Breaking up the bottom allows for percolation, otherwise the dirt becomes stagnant and nothing will grow there.

Thanks for all the replies!