How well is your flagstone spillway/waterfall holding up to SWG?

[Nursenini]

I'm stuck between doing glass tile (expensive) or flagstone on the spillway/waterfall edge of my spa. I love both looks but think I am loving the stone look more. We are doing SWG and my concern, of course, is degradation of the stone (Sahara flagstone) over time from the salt spilling over the edge.

I know there are those of you who advocate no stone at all with SWG.

I'd like to hear from those who went with stone anyway, and have it in constant contact with the water running over it and find out how it is holding up and how long you have had it.

Thank you
Denise

 

[And5555]

I just installed mine so I can't comment on how it holds up. However I did wrestle with this question a lot and researched a bunch.

I ended up using quartzite, which is a very dense flagstone comparable to granite in strength. It's not a sedimentary stone but rather metamorphic. Most of the flagstones seem to do some flaking. Even this quartzite has done some already. I used miracle 511 and am hoping for the best. It's a beautiful stone, though a bit pricey. Will let you know in 5 years.

 

[bdavis466]

Salt gets very bad rap that is not deserved. The salt levels in residential pools are not high enough to create issues with anything but the very softest of stones (ie limestone). More should be said about water chemistry and balance; both of which when well managed will pose little issue.

Quartzite is a good choice and has proven to be very durable. Remember even a manually chlorinated pool still has salt in it, some just as high as a swg pool. Nearly everything you dump in the pool adds salt (chloride) to some degree.

 

[txnole]

We went with remnant granite and it has proven an excellent choice, so far.

 

[JoyfulNoise]

Hey Denise,

If you want to use flagstone as your spillway or in your waterfall design, that is fine. As Brian pointed out, degradation is not as much an issue as is efflorescence and evaporite deposits.

Efflorescence is when water gets trapped behind the stone or, as it the case in a spillway, water is held behind the stone. Then, like a wet sponge, water will infiltrate through the stone and evaporate from any surface exposed to air. As it evaporates, it will leave behind mineral deposits (white stains) that, if left over long periods of time, can become quite hardened and difficult to remove.

Evaporite deposits occur pretty much on any surface that is exposed to cycles of water spray and then drying. Basically, all of the chemicals in the water (salt, calcium,etc) will leave behind films that, like efflorescence, can harden over time. Evaporite deposits on ceramic tile surfaces are easy enough to clean off but on open stone faces (like a stacked stone spillway) they can really latch onto the surface porosity of the stone and be difficult to remove.

The key to slowing both of these processes would be to seal the stone prior to installation using a product like Dry Treat 40SK (there are other manufacturers of these types of sealants as well). Unfortunately, this can add lots of extra cost to the project since the stone often has to be be pre-coated and allowed to dry for the sealant to fully penetrate AND the mason will need to use special mortar materials to bond the stone that has now been sealed against moisture. So if you go this sealing route, you'll want to find a stone mason that has experience in dealing with the products on the market and how to correctly use them.

Hope that helps.

Matt

 

[skylar18]

I have flagstone and salt. Heading into fourth season and no degradation. I do seal it once a year. I will to try to take a picture tomorrow of my spillway. In fact I have 2 waterfalls.

 

[Patrick_B]

I would suggest Quartzite if you can have it put in. When you finally choose, do your best to avoid stone that has obvious layers, or evidence of flaking. Also avoid softer stone, and try to find the hardest most dense material you can find. We are paying the pics for not doing so unfortunately.

 

[skylar18]

Here are pictures.....again, this season will be my fourth. I keep holding my breath but so far so good. All my coping and all stonework is fine.

 

[kevbrim]

I have flagstone and salt. Heading into fourth season and no degradation. I do seal it once a year. I will to try to take a picture tomorrow of my spillway. In fact I have 2 waterfalls.

Skylar, what do you seal your stone with?

 

[skylar18]

Dupont Stonetech Saltwater Resistent Sealer. It is what one of the largest and most well known sealing companies here in Texas uses so I figured if it was good enough for them it was good enough for me. Very pleased with it.