Spa spill over 12" or 18"? Shotcrete tomorrow

[Titan7]

Can't believe I forgot this detail, the spa is 18" above the deck. Any pro/con to either. I believe the flagstone will go over the spillway.

Thx

 

[bmoreswim]

18" is seat height. 12" is kindergarten chair height.

 

[bdavis466]

This shouldn't be something you can change right now. Aren't the forms and rebar already set?

 

[Titan7]

Sorry, I mean how wide the spillover is, just the area that water drops/pours into the pool. Yes the height is set 18" above deck. Sort of waterfall like. Not sure if 12" wide, 16, or 18 is the best for flow? PB said 12-18 is normal, guess I never paid attention before.

 

[bdavis466]

Ah!!!!!!!!!!! Now I understand. I like 18 then...12 is very narrow. Have you considered 24?

 

[atttech-2]

1ft seems narrow for a modern build, I would go with the 18" but definitely a personal decision. Do a Google search on spa spill way width and look in the images section see what appeals to you.

 

[Titan7]

I was thinking 24 but I want to have a louder water feature since it's the only one in the design, PB said flow is really nice at 18" going larger reduces flow a bit. Will definitely go no less than 18" wide.

 

[bdavis466]

The flow is the same, it would just be spread out wider/thiner. I'd imagine the sound would not change much.

 

[JoyfulNoise]

I have exactly what you describe - 18" wide spillway with a flagstone cap over it.

Flow is fine at 18" but I can easily cause a dribble and not a waterfall if the pump is run too low. My spillway is all tile, no inserts, so sometimes I have to give the water in the spa a push with my hand to cause the water to spill out. Either that or kick the pump to high speed to get the water to spill then back to low speed.

If you go 24" I think you might have a flow problem and you'll likely have to run your pump harder to get the spill effect.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

 

[Titan7]

Thx, I am only using 1 pump in the system, I wanted to be able to have the spillover act as a water feature even if we are not using the spa, perhaps 18 is the sweet spot. All these small decisions, I'll be glad when we are done, lol.

 

[OrlandoBull]

We are doing 18", my designer was concerned with going any wider because we are also only doing 1 pump and he thought that we wouldn't get the flow we need. I don't have any real evidence on this as we are just getting started, but, it is a consideration.

 

[JoyfulNoise]

Typically you control the flow of water into the spa using a diverter valve at the equipment pad where return water is split between the spa and the pool. The larger the spillway opening, the more water needs to be diverted to the spa to provide the volume of flow to make the spillway look like a sheer waterfall and not a dribble down the tile face. If the opening is too big, then you will have to divert most of the water to the spa and much less will go to the pool returns; in the extreme you'd have to divert 100% of the return water to the spa. The problem with that is the spa is much smaller volume of water than the pool and so you'll be turning over the spa volume many, many more times than the pool volume. That is bad for pool filtration and can lead to stagnant dead spots in the pool water.

I typically have to split my diverter valve 50/50 with the spa/pool returns to get my 18" spillway to run right. I could run the pump at a higher speed but that costs more. So if I had a 24" spillway, then I'd have to really starve my pool of water in order to get the spillway to run. I'm actually planning to put an actuator on my spillway control valve so that I can turn it on and off from my remote. The spillway runs way more than it should and the excess aeration does affect pool chemistry. So, if you have the ability to add it to your design, you might want to automate the spillway.

 

[Titan7]

Thanks, perhaps I will go 16" wide, I don't want to have an issue.

 

[Titan7]

Typically you control the flow of water into the spa using a diverter valve at the equipment pad where return water is split between the spa and the pool. The larger the spillway opening, the more water needs to be diverted to the spa to provide the volume of flow to make the spillway look like a sheer waterfall and not a dribble down the tile face. If the opening is too big, then you will have to divert most of the water to the spa and much less will go to the pool returns; in the extreme you'd have to divert 100% of the return water to the spa. The problem with that is the spa is much smaller volume of water than the pool and so you'll be turning over the spa volume many, many more times than the pool volume. That is bad for pool filtration and can lead to stagnant dead spots in the pool water.

I typically have to split my diverter valve 50/50 with the spa/pool returns to get my 18" spillway to run right. I could run the pump at a higher speed but that costs more. So if I had a 24" spillway, then I'd have to really starve my pool of water in order to get the spillway to run. I'm actually planning to put an actuator on my spillway control valve so that I can turn it on and off from my remote. The spillway runs way more than it should and the excess aeration does affect pool chemistry. So, if you have the ability to add it to your design, you might want to automate the spillway.

So do you think a 16" spillway will be a better option, sort of splitting the difference between 12 and 18"?

 

[JoyfulNoise]

18" works for me. I have a 3HP IntelliFlo VS pump. So depending on your plumbing setup 18" would probably be fine. Plus, 18" is three 6" tile widths. If you go to 16" you're going to have to snap a tile or use smaller tiles and it may look weird.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

 

[Titan7]

18" works for me. I have a 3HP IntelliFlo VS pump. So depending on your plumbing setup 18" would probably be fine. Plus, 18" is three 6" tile widths. If you go to 16" you're going to have to snap a tile or use smaller tiles and it may look weird.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

That's a great tip on the tile! I love this place, I will go 18" We have a 2.7 HP VS Pump, with 3" plumbing. I will go with with the 18".

 

[Titan7]

Okay back on this again. Sorry to belabor it but I figure if I am going to change I am going to do it now. Since I never had a pool I am not sure how this will all work out. Right now the spill over is 18" wide on the inside of the spill over and 21" on the outside edge. The edge or lip of he spill over is about 1"- 1.25", most of the photos I see have an edge that sticks out further. The piece of stone has a 90 degree edge on half of it and has a chiseled edge on the other half, I assume they did this to blend and have a natural look? I would have preferred the 90 degree square edge across the entire lip as I would think that would allow for a uniform sheer decent?? Also on one side of the top edge there is a scalloped section so when I am pouring water (via a bucket) it appears that the sheer water fall is not even, but I am not sure my bucket experiment is creating the same hydrodynamics as the pump moving a lot more water over the edge.


Again, no experience with this so I am looking for any experience from you guys? Since we don't have plaster I would think it would be easier to change now vs changing out with plaster and water?

Yeah, I am over analyzing but it is a custom build pool so I kind of want what I want. Options are leave it alone and wait to see what the sheer decent looks like. Change it out now, before plaster and water. I can't wait for this to be over.

thanks

 

[bdavis466]

Even if the spillways isn't exactly level or even, the flow from the spa will more than make up for it. The irregularities will only show if you try to run it at lower pump speeds. Unfortunately there really isn't a way to get a good idea of what it will look like beforehand. The stone could also be somewhat chiseled afterward to suit your taste if you end up unhappy.

I'd love to see you conducting your bucket experiment!

 

[JoyfulNoise]

Dang, I can't find it but there was thread on here last fall where someone's spillway was uneven and the flow was uneven too. It was because the stone slab that made up the spillway was not level and the edge was uneven.

I'll see if I can find it.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

 

[bdavis466]

If I recall, his stone was very uneven, visually obvious. Is that what yours looks like? What does the level say?