Leaking spillway on new pool

[cowboysfans]

Pool was completed about a year ago. After it was filled, we immediately noticed water leaking from the spillway/spa on the coping on just one side of the spa. It only leaks when the fountain is running and water is coming down the spillway. The pool builder has been out multiple times, chipping away stone, and re-grouting on more than one occasion. Their last position was that it was just a nominal amount of water and this is normal. It doesn't seem to me that such a leak is normal.

Their latest proposal is to drain the water in the spa a bit and apply Hyrdroban to the surface of the stone and grout of the spillway. I have a few questions here:

1. It seems that any sealant placed on a porous stone that has water flowing across it will only last for a limited period of time. I don't want a temporary solution that masks the problem temporarily and then it returns. If this solution would solve the problem, how long should I expect it to last?
2. Will a sealant darken the stone or change the appearance compared to other stone around it?
3. Based on the picture that I attached, is this even the right approach? Is that where the water is coming from?

Any suggestions would be appreciated. I am considering getting a third party involved based on the pool builder's lack of success so far here.

 

[ajw22]

I think what you have is a poor design for a spillover with too many seams and surfaces for it to ever stay leak free.

One or two layers of Hydroban for waterproofing should have been on the gunite before the stone was put on. Like what is done for glass tile as shown below.

Ask your builder to paint Hydroban on a scrap piece of stone and grout and see how it changes the look.

 

[cowboysfans]

I think what you have is a poor design for a spillover with too many seams and surfaces for it to ever stay leak free.

One or two layers of Hydroban for waterproofing should have been on the gunite before the stone was put on. Like what is done for glass tile as shown below.

Ask your builder to paint Hydroban on a scrap piece of stone and grout and see how it changes the look.

Thanks for your insight here. Makes sense that some waterproofing should have been performed on the shotcrete before the stone went down.

Even if the coloration is acceptable with the Hydroban and it solves the leak, how long should the Hydroban last before it needs to be re-applied? I’m concerned about a temporary patch vs a solution.

 

[JoyfulNoise]

Agree with @ajw22 , it’s a poorly designed spillway. That vertical piece of flagstone is trying to act as a barrier to the water flow but it itself is not waterproof. All of the mortar seems are wicking water as the flow over the spillway puts water pressure on that side. I don’t think there’s a lot that can be done using water barrier materials. They may work at first but they will have to be reapplied over the years. It’s the spillway design that needs to be corrected and that’s big bucks as it basically requires demolition of what’s there and then a rebuild.

 

[cowboysfans]

Agree with @ajw22 , it’s a poorly designed spillway. That vertical piece of flagstone is trying to act as a barrier to the water flow but it itself is not waterproof. All of the mortar seems are wicking water as the flow over the spillway puts water pressure on that side. I don’t think there’s a lot that can be done using water barrier materials. They may work at first but they will have to be reapplied over the years. It’s the spillway design that needs to be corrected and that’s big bucks as it basically requires demolition of what’s there and then a rebuild.

Thanks for your input here. If that vertical piece of flagstone is the issue, what should have been done?

 

[ajw22]

If that vertical piece of flagstone is the issue, what should have been done?

The step stair design should not have been done. The vertical piece is trying to deflect water that should not need a barrier there to control the water. A spillover should have the water fall straight down into the pool.

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Hydroban changes in color from a light sage to an olive green when cured. The color change allows for for ease of inspection.

Hydroban is not intended to be an exterior coating. The installation instructions say:

• Membrane must be covered with ceramic tile, stone, brick, concrete, screeds, terrazzo or other protective surface. For temporary cover, use protection board.
• Do not expose membrane directly to sun or weather for more than 30 days.

 

[JJ_Tex]

I'm certainly no construction expert, but couldn't they pop off the top "stair" and replace it with a longer piece that makes the water fall directly into the pool and bypass the other stairs?

 

[ajw22]

I'm certainly no construction expert, but couldn't they pop off the top "stair" and replace it with a longer piece that makes the water fall directly into the pool and bypass the other stairs?

It is an interesting thought. I am not sure there is enough meat to support the necessary cantilevered section.

The fix is to rip out the stone steps and put in a vertical wall of some type of tile.

We don’t know if the gunite behind the stone is a vertical wall and just the stone was built out or if the gunite has a stair step also.

 

[JoyfulNoise]

This section is part of the problem -



That piece of stone is allowing the water to have a path over to the rest of the coping. I’d need to see how that spa was cut at the shotcrete stage to know exactly what the problem is but my guess is there is a ledge there that should not have been cut that way. The stacked stone that forms the veneer of your outer spa wall should have been flush with the blue tile line.

The spillway is physically connected to the deck. Therefore water will find a way to flow there. Thts how water behaves.

 

[cowboysfans]

It is an interesting thought. I am not sure there is enough meat to support the necessary cantilevered section.

The fix is to rip out the stone steps and put in a vertical wall of some type of tile.

We don’t know if the gunite behind the stone is a vertical wall and just the stone was built out or if the gunite has a stair step also.

Thanks for the insight. The shotcrete is just a shelf. The stair step is built out of the veneer only.

 

[cowboysfans]

This section is part of the problem -

View attachment 450915

That piece of stone is allowing the water to have a path over to the rest of the coping. I’d need to see how that spa was cut at the shotcrete stage to know exactly what the problem is but my guess is there is a ledge there that should not have been cut that way. The stacked stone that forms the veneer of your outer spa wall should have been flush with the blue tile line.

The spillway is physically connected to the deck. Therefore water will find a way to flow there. Thts how water behaves.

thanks! Here are the best pictures I have of the steel and then the shotcrete.