Building my own 12X8 Plunge Pool

My shotcrete/gunite guy mentioned installing hydrostatic pressure relief valves on each drain. Said that it couldn’t hurt anything and if there is ever a heavy rain storm with water below the pool with nowhere to go it’ll release into the pool rather than any issues with the shell heaving
100% go with them. One point of clarity is that the weight of the water in your pool shell holds it down and in the ground. The hydrostatic valves are only open during construction and if you ever need to drain the pool down the road. The plaster company should close the valves before filling and you will hopefully never need to open them again (but you will have them if you ever need to drain).
 
Primarily for piece of mind to keep suction constantly to the pump if the water line ever were to drop below skimmer when I’m out of the country for weeks at a time in the summer.
Marco,

If the water drops below the skimmer, what is going to turn on the main drain or isolate the skimmer line?? When the water level drops below the skimmer, it will just start sucking air, and the main drain will not work, unless you have some kind of diverter, which only work about 50% of the time.. At least for me.. :mrgreen:

Thanks,

Jim R.
 
Marco,

If the water drops below the skimmer, what is going to turn on the main drain or isolate the skimmer line?? When the water level drops below the skimmer, it will just start sucking air, and the main drain will not work, unless you have some kind of diverter, which only work about 50% of the time.. At least for me.. :mrgreen:

Thanks,

Jim R.
Jim,

Thanks for response
I’m going to have separate suction lines for each (recommendation from shot Crete guy when I expressed this concern)

Essentially, two suction lines from the pool to the pump. One from the main drains AND one from the skimmer. T’d off at the pump with a ball valve for each line.

When I go away for 2-3 weeks in the summer, that line to the skimmer will get turned off and the suction will come primarily from the main drains
 
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100% go with them. One point of clarity is that the weight of the water in your pool shell holds it down and in the ground. The hydrostatic valves are only open during construction and if you ever need to drain the pool down the road. The plaster company should close the valves before filling and you will hopefully never need to open them again (but you will have them if you ever need to drain).
Thanks for the response

Here’s a bit of concern. Shot Crete getting completed next week between Thursday 2/27 and Friday 2/28

I don’t plan on tiling the pool and completing finish plaster until Early-Mid April

The shotcrete/gunite shell will be sitting empty for approximately 6 weeks until I get everything plastered and tiled.

I plan to tarp it and keep curing blankets over it the entire time.

I guess my concern is the shell sitting so long in between finish. Does that open me up to chance for it to pop/swell in March with any heavy rains?

I want to ensure the shotcrete cures for the full 30 days before doing all the finish work and filling the pool
 
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Thanks.

 
Thanks for the response

Here’s a bit of concern. Shot Crete getting completed next week between Thursday 2/27 and Friday 2/28

I don’t plan on tiling the pool and completing finish plaster until Early-Mid April

The shotcrete/gunite shell will be sitting empty for approximately 6 weeks until I get everything plastered and tiled.

I plan to tarp it and keep curing blankets over it the entire time.

I guess my concern is the shell sitting so long in between finish. Does that open me up to chance for it to pop/swell in March with any heavy rains?

I want to ensure the shotcrete cures for the full 30 days before doing all the finish work and filling the pool
The shotcrete company should have 1-2 weep holes at the bottom of the pool that allow groundwater to enter into the shell and keep the pressure from popping it out of the ground before the hydrostatic valves are installed.

Make sure you have a good plan to water the gunite, especially for the first week.

Your timeline sounds like a standard gunite build timeline. You are about to enter what can be a frustrating period of waiting and downtime after a flurry of activity with the dig/rebar/gunite.
After a few weeks of curing, they will likely start on the coping/tile, equipment, finishing the plumbing, decking, etc. and your flurry of activity should pick back up.

Also take a look at Pool Shool and some of the good articles for construction, including this one for you:

 
The shotcrete company should have 1-2 weep holes at the bottom of the pool that allow groundwater to enter into the shell and keep the pressure from popping it out of the ground before the hydrostatic valves are installed.

Make sure you have a good plan to water the gunite, especially for the first week.

Your timeline sounds like a standard gunite build timeline. You are about to enter what can be a frustrating period of waiting and downtime after a flurry of activity with the dig/rebar/gunite.
After a few weeks of curing, they will likely start on the coping/tile, equipment, finishing the plumbing, decking, etc. and your flurry of activity should pick back up.

Also take a look at Pool Shool and some of the good articles for construction, including this one for you:

Wouldn’t the pressure relief valves and floor drains be installed prior/in conjunction with the shotcrete?

Looking at the diagram provided via Hayward on the instructions it looks like they should be set into the concrete
 
Install one hydrostatic valve, not two. One is enough to protect your pool.

They develop leaks. No reason to create more points of failure and more things to test if you begin losing water.

There are YouTube videos about hydrostatic leak detection and replacement.
 
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Wouldn’t the pressure relief valves and floor drains be installed prior/in conjunction with the shotcrete?
Hydrostatic relief valve is installed after plaster. You do not want shotcrete or plaster or other materials clogging it.

The hole where the relief valve is screwed into can be left open for protection until plaster is applied.
 
Hydrostatic relief valve is installed after plaster. You do not want shotcrete or plaster or other materials clogging it.

The hole where the relief valve is screwed into can be left open for protection until plaster is applied.
 

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It literally gets installed into the gravel below the shotcrete connected to the drain, no?

How could this be done during the plaster stage? There’s going to be 6-8 inches of shotcrete and rebar already installed
 

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It literally gets installed into the gravel below the shotcrete connected to the drain, no?

How could this be done during the plaster stage? There’s going to be 6-8 inches of shotcrete and rebar already installed
The plastic sump gets installed during the plumbing rough in before shotcrete.

The sump has holes at the bottom for the hydrostatic valve or plugs.

The hydrostatic valve is screwed into the sump after plaster before the cover is screwed onto the sump.
 
Everything passed inspection with rebar and first round of electrical last Wednesday. Shotcrete shell is done along with all plumbing stubbed up to the pad and I have everything backfilled.

Now the month + long wait begins for plaster.

Couple questions because I overthink everything….

-Does the shotcrete look terrible? Like is this more rough than a typical shotcrete pool shell? I was watching the majority of the process and it was constant running around for 2.5 hours moving plywood shields, removing forms, troweling, etc..

-What are the going rates for plastering a pool? I’ve gotten two quotes so far and one was $7900 and the other was $11,000. That seems extremely high considering the pool is only 12X8 approx. 300 sq ft of plaster space.

-Should I be doing a pressure test of the pipes/plumbing before we plaster and fill? Shotcrete guy said he’s never done that for a pool build and the township inspector also said they don’t require that either. Maybe I’m just overthinking everything but I worry we’ll run into some problem with plumbing once the pool is filled and ready to use.
 

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-Does the shotcrete look terrible? Like is this more rough than a typical shotcrete pool shell? I was watching the majority of the process and it was constant running around for 2.5 hours moving plywood shields, removing forms, troweling, etc..
Rough shotcrete surface is fine and will help the plaster adhere to it.

The edges look clean and sharp.


-What are the going rates for plastering a pool? I’ve gotten two quotes so far and one was $7900 and the other was $11,000. That seems extremely high considering the pool is only 12X8 approx. 300 sq ft of plaster space.
Plastering costs vary widely by region.

A small pool takes as much time for setup and cleanup as a larger pool.

-Should I be doing a pressure test of the pipes/plumbing before we plaster and fill? Shotcrete guy said he’s never done that for a pool build and the township inspector also said they don’t require that either. Maybe I’m just overthinking everything but I worry we’ll run into some problem with plumbing once the pool is filled and ready to use.
Yes a pressure test should have been done before pipes are backfilled.


After laying all the pipes in the trench, join them together to make a pressure test configuration with the poolside fittings plugged. Pressure test the plumbing for 24hrs minimum, then backfill under pressure. The pipes move when back-filling. Leave the pressure test rig on for a few days, water the trenches to help settle, and hand-tamp them as you fill if narrow. After all that, cut them and do the pad plumbing using diverter valves.

You should be watering the gunite…

 
He said no water needed because it’s not the middle of the summer and it quite literally light showered the evening after the spray

I appreciate the info on the pressure test. Do all the typical pool GCs do this? Both my shotcrete guy and township inspector acted like I was silly and unnecessary for asking about that
 
He said no water needed because it’s not the middle of the summer and it quite literally light showered the evening after the spray

One light shower does not keep the shell hydrated for 7 to 28 days.

As the chart shows, the first 7 days are critical for keeping the concrete moist if you want to achieve full 28-day strength.

I appreciate the info on the pressure test. Do all the typical pool GCs do this? Both my shotcrete guy and township inspector acted like I was silly and unnecessary for asking about that
There is no typical GC.

I don’t know how you can know every joint is good without a pressure test. And a bad joint or two is often found.

The pressure test is often left in place until the equipment will be installed. That way you can find out if the plumbing is damaged by other work around the pool.
 
Building a 12X8 plunge pool. Just finished plumbing pressure tests today. Everything passed, equipment all tied into the plumbing and final backfill to take place this weekend. I will be ready for plaster and tile next week (as soon as my travertine coping arrives)

Question and feedback from everyone here….

Does new shotcrete require a “bond coat” for the plaster? I was under the impression that the bond coat was only needed to prevent delaminating on re-plastering jobs where you didn’t get it down to bare concrete/shotcrete

My plaster/tile contractor says they recommend it to everyone but also said they don’t do it a lot on new builds unless the GC requests it but always do it on re-plaster jobs.

It’ll save me about $900 total which would be great for a project we’ve already spent more than we wanted. But at the same time if it’s necessary and it will provide value than I’m on board

Any feedback much appreciated.

Thanks
 

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See bullets 3 and 4 under "Installation Tips" about bond coats...

 
Let me start by saying we are very pleased and happy with the quality of this work. It looks awesome, but….coping grout is gray and we wanted white

Granted I take blame for this as I didn’t communicate this ahead of time and just told them white grout on the water line tile. I guess I thought the coping would also be white

We were both at work when the job was done and came home and noticed the gray

What are my options here? Staining it white? Overcoat with a thin layer of white grout?

Any feedback much appreciated
 

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