Flagstone coping, SWG, and what to do now?

[boomer4ou]

Hello All - had our pool installed appx 18 mos ago & selected OK Flagstone for coping and SWG (D/FW area). The builder did not emphasize the extra care required with this combination, suggesting sealing the flagstone coping as "optional" at the build and that "spraying off the entry/exit areas with a hose after use" would be sufficient to minimize flagstone wear.

Now, I'll say that (while I'm no Geologist), I do have the common sense to know saltwater will have an impact on stone over time. What I didn't know was that, without sealant, "over time" can be as little as 6-12 months.

We called the builder out around the 10 month mark to review and an assistant surveyed; said we should have 17 stones replaced and that the wear was in fact faster that it should have been (explaining that batches of stone all have different makeup & "sometimes we get bad batches"). But shortly after, a supervisor returned to say 1) it was "normal" 2) sealing at the build would not have been a good idea, because the stone needed some wear to rub off the top layers before sealing and 3) with a good pressure wash to pull up any flakes in progress + sealant (and annual sealant thereafter) we should be fine.

My questions:
- does this sound like a reasonable course of action: a good pressure wash / brushing / sweeping to pull up any flakes in progress + sealant?
- sealant suggestions (don't mind spending a little if it works and doesn't need multiple times a year)
- does this sound a little sloppy (or even wrong) as far as builders go?

Thanks In Advance...

 

[boomer4ou]

:arrow: bump - any opinions?

 

[chem geek]

Salt splash-out and recrystallization can damage softer stones. This is especially true for limestone, but may be true for some flagstone as well. Though it makes sense to seal the stone, I don't know enough about this to comment on the advice you were given in terms of pressure washing nor what specific sealant to use for that particular type of stone. I know that for our textured concrete we use Glaze 'N Seal Multi-Purpose Sealer, but that isn't natural stone.

 

[tmoss]

I live in the dfw area as well. My neighbor's sw pool has OK flagstone. His pool steps and bottom look like the beach. Well, not quite. Sand is always leaching out into the water and collecting in little piles where there's stagnant flow. I have a feeling many people will regret using this stone in time for this reason.

It's been a very popular choice in new construction around here. We ultimately decided we didn't like the look of it. Our PB didn't say OK stone was a bad choice. But he didn't deny my concerns, either. His advice was similar to what you were told. May be the same builder. We ended up going with travertine coping and stamped concrete decking. Pleased with the results.

I will say that after 3 summers it's time to seal everything. I don't think the stone guys sealed the travertine. But the concrete was. And I want to keep the sw from having a chance to work it's way into cracks and such and stop eating away at the surfaces. Rinsing the coping and decking is a good practice and I try to do it weekly during the swim season.

I'm not surprised you're having issues. PB's should discourage the use of soft, porous products when selling swg systems. Salt water will destroy just about anything given enough time. I'd be very careful not to power wash any stone particles into the pool. And I would put multiple coats of sealer as well. Or at least a good coat of something very good. I'm thinking of using a Deck-o-seal product. Not cheap. But I want durability. Any opinions out there?

As for the builder being sloppy in not telling you everything up front I don't know. They want to sell a pool. Which means, among other things, that they want you to believe the pool you're wanting will be easy to maintain with minimal time and effort and money. As for "wearing off the top layers before sealing", I'd like to know why that bit of information was witheld until you have an issue. I call BS. If they're a stand-up company they should prep and seal it for free since it's a known problem with this type of stone and it appears you're having an abnormally high wear rate.

I don't see how a PB can offer such a stone knowing these things will happen without full disclosure before any money changes hands. Then again, it might scare people away. Give them a chance to make it right. Ask them for a list of other clients who put in the same stone and see if they're having problems. Good luck.

 

[fighting_irish]

It is not just flagstone and limestone that errode. I have seen this in travertine, slate, and even quarzite. All natural stone should be sealed whether it is SWG or not. This is recommend by all stone yards. As far as the builders warning about the softer stone. I personally think it is all builders responsibility to warn the customer of the adverse effects of SWG systems instead.
I install these sytems just like any other builder. But I educate my customers of what problems can occur from the use of these system from stone errosion to equipment problems. As well as the precautions to take to prevent these problems if they are to use a SWG.