SOS: Pool floated during renovation with hydrostatic relief valve installed

[SLU81]

Seeking advice: our pool floated with a hydrostatic relief valve installed. Our pool contractor recently installed a Hayward Hydrostatic Relief Valve (SP1056) during the remodel of our pool. Our pool drain at the bottom of the pool no longer is operational so the contractor was relying on the hydrostatic relief valve to relieve pressure from the water table. We live in Missouri, and the contractor left the pool with about 18 inches of water in the deep end for three weeks—Important to note as well is that we had 8 feet trench around the deep end of our pool that have been backfilled with rock awaiting concrete installation. After three weeks with only 18 inches of water in the deep end of the pool, we had a 1.2 inch rainfall. Our pool floated.



The contractor went into the bottom of the pool and realized that the pressure relief valve was stuck and it took some pulling to get the spring load attention to pull up. As soon as he manually did this water entered the pool.



Question: (1) Is the relief valve meant to relieve the pressure under the pool regardless of how much water is in the pool? (2) Or should there be an adequate amount of water in the pool to apply enough reverse pressure on the valves so that the spring load tension works? (3) if the pool is empty or only has a little bit of water in the pool should the relief valve be pulled open so that it stays open at all times until the pool can be filled?

(4) What level of pool water is considered safe enough to manually close the relief valve and allow it to work on its own?

(5) What other considerations (not mentioned above) could be given for why the hydrostatic relief valve did not open causing the pool to float?

 

[JamesW]

It’s a myth that an open hydrostatic valve can prevent a pool from floating.

“Relieving the pressure” does not happen just because the hydrostat is open.

The science related to if a pool will float is simple, but, in practice, predicting when a pool will float is extremely difficult.

The amount of water being displaced determines the amount of upward force, or lift, that acts on the pool shell.

What type of pool do you have?

Can you show some pictures?

Did the pool float equally all over or more on one side than the other?

 

[JamesW]

The contractor went into the bottom of the pool and realized that the pressure relief valve was stuck and it took some pulling to get the spring load attention to pull up.

I highly doubt that this is true unless the valve was exposed to glue or primer which caused it to stick closed.

In any case, the contractor should have made sure that the valve was operational before installing it.

You should never rely on a hydrostat to prevent floating.

You need to have wells that can be used to monitor the ground water and automatic pumps in the wells to keep the ground water pumped out.

Is the contractor trying to deny responsibility?

 

[Newdude]

The amount of water being displaced determines the amount of upward force, or lift, that acts on the pool shell.

+1. Whether it's ground water or a flood from a big storm, only so much water can flow through the valve. Then the rest does whatever it feels like instead.

Or if it's less water than the valve can handle, but the pool is full, the pool isn't going to get full-er.

 

[JamesW]

They should not have installed the hydrostat until they were ready to fill the pool.

They should have had well points or well holes with sump pumps that could manage the water under the pool.

In any case, it is the responsibility of the contractor to make sure that the pool does not float.

How high did the pool rise out of the ground?

What does the contractor say needs to be done now?

 

[SLU81]

It’s a myth that an open hydrostatic valve can prevent a pool from floating.

“Relieving the pressure” does not happen just because the hydrostat is open.

The science related to if a pool will float is simple, but, in practice, predicting when a pool will float is extremely difficult.

The amount of water being displaced determines the amount of upward force, or lift, that acts on the pool shell.

What type of pool do you have?

Can you show some pictures?

Did the pool float equally all over or more on one side than the other?

1. size pool is about 30,000 gallons
2. pool did not float equally. It floated about 8 inches at the center of the deep end, and narrow to about 5” approximately at the middle of the pool.
3. First photo: pool before float, showing level of water left in pool by Contractor from April 25 through May 18.
4. other photos show areas where major digging along the side of the perimeter of the pool had been completed to replace copper piping and to dig down to the bottom of the pool to reposition side drains. Area was backfilled with pea gravel. wondering if water absorbs through that gravel faster and caused the problem to mediately raise the pool/float even with the HPRV

Note: The contractor had about 3-4 made of water in the pool until April 25. Contractor then pumped the water out of the pool to change the light fixture—Leaving approximately 18 inches of water, possibly 2 feet at the drain. Not sure if something happened at the time that they pumped the water out that could’ve caused that HPRV to fail? Or if they closed it.

But Contractor left site for three weeks while working on another project and left the pool with this amount of water in it. Close to three weeks later we had a rain storm and several days later the pool floated

 

[JamesW]

What does the contractor say happens now?

Are they going to fix it or are they going to try to avoid responsibility?

 

[JamesW]

Maybe it's the pictures, but it looks like more than 8".

In any case, it's a bad situation and there is no easy fix.

 

[SLU81]

I highly doubt that this is true unless the valve was exposed to glue or primer which caused it to stick closed.

In any case, the contractor should have made sure that the valve was operational before installing it.

You should never rely on a hydrostat to prevent floating.

You need to have wells that can be used to monitor the ground water and automatic pumps in the wells to keep the ground water pumped out.

Is the contractor trying to deny responsibility?

HPRV was installed early April. April 16 photograph attached showing the first muddy water released into the pool from the HPRV which was operational at that time. This inflow of water happened a second time after this. A week later they drain the pool leaving about 18 inches of water

note: the water was filled with pollen droppings, Oakleaf helicopters, mud etc and I do not believe the contractors cleaned that out. Could the muddy/dirty water impact the efficacy of the HPRV?

2. Regarding your comment regarding not relying on the HPRV to prevent a pool from floating: (i) should the contractor have filled pool with water to skimmer after the HPRV was installed (ii) If Contractor still needed to work on the pool, should they have removed the HPRV to prevent a pool float? any other ideas?

 

[SLU81]

What does the contractor say happens now?

Are they going to fix it or are they going to try to avoid responsibility?

Contractor said it was their fault, they had liability insurance. Three weeks have passed and they are still waiting to hear back from their insurance company as to what would be covered (assuming based upon who the insurance company believes is at fault).

Options discussed where to (i) pressure check the pipes and if they are still operational fill the pool with the hopes that it would settle (ii) take out the bottom of the pool, followed by rebuilding the pool using the sides of the existing pool as a shell. The shell would not be attached to the old pool but it would make the pool about 10 inches smaller around the circumference on all sides (iii) tear out the whole pool and start over, (iv) If pipes are still working, I recent option was discussed to dig holes in the bottom of the pool, Phil raised ground under the pool with Concrete and then shave off the top of the pool and start over with the coping and tile with a new pebble Tec surface.

Those were all the options that were discussed during week one. Nothing has been discussed since because he is waiting for his insurance carrier to reply. Meanwhile we still only have a little bit of water in our pool with 1000 tadpoles swarming in the pond like water.

any ideas on what can be done to kill off the tadpoles without compromising the repair options?

 

[SLU81]

Contractor said it was their fault, they had liability insurance. Three weeks have passed and they are still waiting to hear back from their insurance company as to what would be covered (assuming based upon who the insurance company believes is at fault).

Options discussed where to (i) pressure check the pipes and if they are still operational fill the pool with the hopes that it would settle (ii) take out the bottom of the pool, followed by rebuilding the pool using the sides of the existing pool as a shell. The shell would not be attached to the old pool but it would make the pool about 10 inches smaller around the circumference on all sides (iii) tear out the whole pool and start over, (iv) If pipes are still working, I recent option was discussed to dig holes in the bottom of the pool, Phil raised ground under the pool with Concrete and then shave off the top of the pool and start over with the coping and tile with a new pebble Tec surface.

Those were all the options that were discussed during week one. Nothing has been discussed since because he is waiting for his insurance carrier to reply. Meanwhile we still only have a little bit of water in our pool with 1000 tadpoles swarming in the pond like water.

any ideas on what can be done to kill off the tadpoles without compromising the repair options?

Meant to add That Contractor is somewhat backpedaling and taking the blame, stating that their attention to detail was superb and there was nothing they could’ve done. Claiming we must have Highwater tables? We have lived in this house 20 years and we don’t believe we have a high water table. We are not near any lakes, rivers, streams, or creeks

 

[SLU81]

Maybe it's the pictures, but it looks like more than 8".

In any case, it's a bad situation and there is no easy fix.

I did go out to take a measuring tape and it is higher than 8 inches. The difficulty is the gravel rocks settled underneath the area that the 5 inches of concrete would be poured in some instances.

Attached various pictures from the deep into the skimmer— adjust number to subtract 5 inches of concrete decking to be added, and to account for the rock falling into the sides of the pool crevice

 

[JamesW]

The hydrostat can get jammed with sand and become stuck.

If you have a high water table, then it is the contractor's responsibility to know that and to take the necessary precautions.

Even if you don't have a high water table, the contractor needs to take the necessary precautions to avoid floating when it rains because the rain water can surround the pool and saturate the area enough to float the pool.

You should always get the work done as quickly as possible to avoid problems.

Leaving the pool empty for weeks without providing any sort of ground water control methods was irresponsible and cavalier.

If the work had to be delayed, you can fill the pool or provide the necessary ground water control methods.

 

[JamesW]

This might fall under professional liability or "Errors and Omissions" insurance, which is a specific type of insurance that is different from and separate from general liability insurance.

Many companies do not have errors and omissions insurance.

E&O covers professional mistakes or omissions.

It might be considered under general liability, but that will be determined by the insurance company.

It partly depends on if the issue was considered to be foreseeable and preventable and if it is considered to be something a professional should have been able to prevent as part of the scope of the job.

 

[dfwnoob]

I'm so sorry this has happened to you, I can't even imagine what a headache that is. I hope they end up doing the right thing without you having to get an attorney involved.

 

[JamesW]

Is this going to be a diving pool where the depth has to be a specific amount to provide the necessary diving envelope?

I suspect that the best option will be to remove what you have and start over.

I don't think that it will go back down in any significant way, but it is hard to tell for sure.

 

[Abraxos]

Curious what the resolution was! What stl company did this? We are having a hydrostatic installed in STL in an older pool and would like to avoid this!

 

[Rancho Cost-a-Lotta]

His last activity was a day after his last post. Try a DM. I believe the default is email notification which may get his attention. Maybe a pinG will work... @SLU81