How to build a wall with sheer decent waterfall?

[Veccster]

We start dig in 5 days so I'm making sure I have everything thought out in advance. I decided today that I would like to build a small rock wall in the deep end of the pool - with a sheer decent waterfall coming out of it. Our deep end is only 6' so I'm not making it too high as kids will likely jump off it.

My question is how are these typically built? Is it framed out with wood, covered in cement board and then veneered with stone? Or are they built with cinder blocks?

If I'm not going to have the builder do this, do I just run a 2" pipe to that location and cap it off? What else needs to be taken into consideration if I plan to add this feature?

Thank you.


Examples are below.

 

[Tampa Scott]

At the least ask your pool builder to do the plumbing for the waterfall. We're going with a rock waterfall made of boulders. The pb will do the plumbing and I hired a guy to build the waterfall. Not sure about construction for what you want but I would do all masonary to avoid future rot.

 

[JoyfulNoise]

These sheer descents can be tricky if you don't plumb them correctly. Flow rate of water matters! I am of the opinion that low head water features like these should have dedicated plumbing loops (their own drains and return to the pool) with their own waterfall pumps. Waterfall pumps are designed to work for applications where high flow rates are needed but not necessarily high pressure (i.e., low head high flow). As such, these pumps are designed to lift water vertically no more than about 10' or so but they can supply flow rates of well over 80GPM (some as high as 150GPM). Scuppers, sheer descents and waterfalls are all examples of open pipes that need high flow rates. Most of the sheer descent manufacturers will spec a minimum flow rate for a given sheer.

Pool builders often ignore this detail and will either use a really overpowered pool pump (high head, high flow) OR they will try to tie the sheers into the main pool plumbing loop and thus rob the filtration system of flow. While it's a little more expensive to add the additional equipment at the pad as well as spec a separate plumbing loop, it is far, far easier to control and run a water feature that has an independent loop rather than fiddling with valves to try to achieve the right look. One problem people run into when they cut a sheer into the main plumbing system is that they will try to get more water flow to the sheer descent (as opposed to pool returns) and the head loss drops on the the return side of the plumbing to a point that is too low for the pool pump and the pump starts to rattle and make noise.

 

[swimcmp]

First and foremost make sure that the weight of the wall is taken into consideration. You will want to have concrete piers going down to undisturbed soil. We just built one that is 20' long overall and has 20 4" piers setting on 4" thick concrete that is on virgin soil.

 

[Foosman]

One common way is the pool builder brings up rebar above the water level and the structure is filled with gunite during the build. A ledge is left around the gunite so rock can be attached...often ledger stone is used (these are pieces of stone cut thin so they look like stacked stone). You can buy all kinds of ledger stone from stone yards, home depot and pool supply companies.

 

[river rat]

I used cinder block for the base form and then wrapped flagstone around.

 

[gwegan]

First I would go on the Jandy site and read their installation manual for their sheer descents.

 

[Veccster]

These sheer descents can be tricky if you don't plumb them correctly. Flow rate of water matters! I am of the opinion that low head water features like these should have dedicated plumbing loops (their own drains and return to the pool) with their own waterfall pumps. <snip>

Great info....thank you! I guess I just assumed I could use the main VS pump. The waterfall will not be running too often - only during swim times. I would probably plan to circulate the pool on lower RPM's during the night. When running sheer descent and/or the deck jets, I thought the VS pump would be enough. I'd just divert the water from the return jets? No?

I have a slide, deck jets and sheer descent. These would probably all be running while swimming. During the night, I'd turn them all off and run the circulation jets.

I'm automating the system with a Jandy iAqualink.

UPDATE: Jandy does not recommend a separate loop unless installing multiple falls or more than 6'. And then you need to add a separate pump, separate filter and the proper anti-entrapment fixtures on the suction line. As I'm only looking for 2' falls, I'll keep this on the main loop. Thank you for the consideration though.

One common way is the pool builder brings up rebar above the water level and the structure is filled with gunite during the build.<snip>.

Thank you. We are installing a vinyl pool so no gunite or rebar. But I do plan to use ledger stone to match the stone that is on the side of our house.

I used cinder block for the base form and then wrapped flagstone around.

Yeah, I was thinking about it more and think cinder blocks would be easier, sturdier and longer lasting (no rot).

First I would go on the Jandy site and read their installation manual for their sheer descents.

Good point. I guess I should pick the sheer descent first and work backwards.

 

[gwegan]

If you are doing a vinyl liner then you should consider building it out of steel studs, cement board and lightweight veneer stone.

Go read through some threads in our outdoor kitchen forum. Also purchase for $10 the Symphony outdoor kitchen PDF book. It goes through building outdoor kitchens for beginners which is the same skill set and tools required for this job.

I would not place a cinder lock structure on top of metal or composite pool walls that are not designed to handle the load.

 

[JoyfulNoise]

Waterfall, slide and deck jets....that's a lot of flow! Also, you have a mix of water features there - low head (waterfall & slide) and high head (deck jets).

I would put the slide and sheers on a separate plumbing loop with a waterfall pump. There's no need to use the filtration system for that. I would put them on a split 3-way valve so you can select one or the other or 1/2&1/2.

I would put the deckjets on the main pump and automate them with a shutoff valve.

 

[Veccster]

If you are doing a vinyl liner then you should consider building it out of steel studs, cement board and lightweight veneer stone.

Go read through some threads in our outdoor kitchen forum. Also purchase for $10 the Symphony outdoor kitchen PDF book. It goes through building outdoor kitchens for beginners which is the same skill set and tools required for this job.

I would not place a cinder lock structure on top of metal or composite pool walls that are not designed to handle the load.

Good point. Cinder blocks would be heavy. Are steel studs sturdy enough to support the veneer stone.....and an adult that chooses to stand on top of it? I've never used steel studs so I'm not too familiar with them.

Waterfall, slide and deck jets....that's a lot of flow! Also, you have a mix of water features there - low head (waterfall & slide) and high head (deck jets).

I would put the slide and sheers on a separate plumbing loop with a waterfall pump. There's no need to use the filtration system for that. I would put them on a split 3-way valve so you can select one or the other or 1/2&1/2.

I would put the deckjets on the main pump and automate them with a shutoff valve.

If doing a separate loop, where do I put the suction port? And what does a suction port look like for that? I'd prefer not to do a drain at the bottom. I suppose it has to have anti-entrapment on it?

Just one more time....so 2" pipes with a 3hp vs pump and each fixture on an adjustable valve...is too much for one pump? Even if running these fixtures when standard returns are shut off? Can I ask...what is the downside? Not enough height on the deck jets? Broken flow on the sheer decent?
Maybe I don't run the deck jets when I'm running the slide???

I prefer simplicity as it's less to fail and less to be frustrated with.

 

[JoyfulNoise]

Anti entrapment wall drains in the shallow end is how mine is setup.

I really don't think you'll be able to do it with just valves. You need to calculate the head loss on the return side to know what amount of flow the pump can achieve. If the head loss drops to low on the return side, you'll get pump cavitation trying to achieve high flow rates at low pressure. Adding the necessary amount of head loss to keep the pump quiet may cut the flow down so that none of the water features look right or work well.

I understand your keep it simple approach but, believe me, you can easily make the system non-operational by not carefully understanding the hydraulics. Just slapping a bigger pump on it is not the right approach.

Perhaps others with more hydraulics knowledge can chime in and clarify.

 

[daddymack]

Good point. Cinder blocks would be heavy. Are steel studs sturdy enough to support the veneer stone.....and an adult that chooses to stand on top of it? I've never used steel studs so I'm not too familiar with them.




If doing a separate loop, where do I put the suction port? And what does a suction port look like for that? I'd prefer not to do a drain at the bottom. I suppose it has to have anti-entrapment on it?

Just one more time....so 2" pipes with a 3hp vs pump and each fixture on an adjustable valve...is too much for one pump? Even if running these fixtures when standard returns are shut off? Can I ask...what is the downside? Not enough height on the deck jets? Broken flow on the sheer decent?
Maybe I don't run the deck jets when I'm running the slide???

I prefer simplicity as it's less to fail and less to be frustrated with.

I run 2 bubblers and 3 24" sheer descents on one 3hp pump... without a problem. I have a Valve (one of my autovalves) between the bubbler line and waterfall line. The bubblers are split right after the pump/valve with separate valves to use to control flow and equalize, and the three water falls are one pipe to a three way split, each with their own valve to control flow and equalize. I have a raised bond beam out of Gunite and the tiler set the water falls and then the plumbing was hooked up to the rear of the water falls. The suction port is on the side of the pool.. facing away from the house so you can't see it. It all works magically.

One thing you might want to think about... especially if your pool has a tendency to get stuff in it, is a small filter so that it catches anything that can clog up the descents...

I have pictures in my build..

 

[Veccster]

Ok...talked with PB and we are doing a 2nd loop with a dedicated pump for the waterfall and slide. Going to add 2 wall suction ports lower in the deep end...at least 3' apart for entrapment prevention.

Is there a big need to put filtration on this loop?

For building it, he is recommending concrete cinder blocks. Since it's a vinyl pool with steel walls, he will pour a deeper footer in that area to increase the support of the decking.

 

[JoyfulNoise]

3' seems a bit far to me. I have two wall ports for my waterfall suction and they are spaced about 24" apart center-to-center.

No need for any filtration, mine dies not need it. I rarely, if ever, have to pull out the pump strainer basket. Just make sure that the sheer descents are installed with the proper rock/sediment trap before the sheer to catch any debris before it gets to the sheer and make the back of the sheer accessible of you can. If not possible, that's ok too.

 

[Foosman]

What pump are you going to use?

 

[Veccster]

3' seems a bit far to me. I have two wall ports for my waterfall suction and they are spaced about 24" apart center-to-center.

No need for any filtration, mine dies not need it. I rarely, if ever, have to pull out the pump strainer basket. Just make sure that the sheer descents are installed with the proper rock/sediment trap before the sheer to catch any debris before it gets to the sheer and make the back of the sheer accessible of you can. If not possible, that's ok too.

Though I'd like to, I just don't see how I make it accessible. If I need to, I can always cut the mortar out and remove top stone. Not ideal but possible.

I'm not sure where the suction ports will end up. Perhaps on a corner wall. I don't know until I see it. But he did say he'd keep them low so it draws cold water.

What pump are you going to use?

Very much open to suggestions! Everything else is Jandy. And I don't think I need VS.

I'll either be running 1 feature or both. Can I get away with single speed?

 

[JoyfulNoise]

I would suggest a 2-speed pump at a minimum. I have to run my waterfall daily for disinfection reasons (small pools on the waterfall) and it's run by a single-speed, 3HP WhisperFlo pump; total overkill. If all you want to do is run the sheers for a little daily show, then the low speed side of a 2-speed motor with the splitter valve directing all the water there may be more than enough.

Depending on your lift to the slide and the head loss in your plumbing, a waterfall pump may be all you need. A waterfall pump is designed for low head, high flow applications and moves water more efficiently than a pool pump. I'd see if that's an option if all you want is a simple single speed pump.

 

[Veccster]

Any guesses on the dimensions of this:

Maybe an 18" descent with 3" on either side? Center being 24" wide and sides being 18" long. Total width is 5'. It would be in the center of an 18' wide pool.
Does that seem too small?

Height looks to be 12" sides and 18" center?

 

[PoolguyinCT]

3' seems a bit far to me. I have two wall ports for my waterfall suction and they are spaced about 24" apart center-to-center.

No need for any filtration, mine dies not need it. I rarely, if ever, have to pull out the pump strainer basket. Just make sure that the sheer descents are installed with the proper rock/sediment trap before the sheer to catch any debris before it gets to the sheer and make the back of the sheer accessible of you can. If not possible, that's ok too.

3 ft is a code provision.


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