Sandwash Failing

[PeteC]

After four years I've started to notice that the sandwash on the pool steps, and on the overflow rim is starting to deteriorate. Only takes a brush of a hand or the swipe of a foot to loosen some small pieces of stone and subsequently the floor of the pool is starting to look like a beach after use.

Has anyone had to remove or repair submerged stonewash and if so, how is it done? How thick of a layer is usually used over the concrete? Maybe sufficient just to concrete over it to seal it all up?

I know I'm looking at draining the pool and perhaps the best fix is to get rid of it, or cover it, and put in tile steps, and a slate overflow rim. Big job I'm afraid, and I guess if I do all of that and drain the pool, I could get the tile grout fixed/replaced as well where it has failed.

I may be seeing the long term effect of using a saltwater system, I'm not sure.

Anyway, appreciate any advice if anyone has had similar problems. Thanks. Pete

[Super Joe]

Has anyone had to remove or repair submerged stonewash and if so, how is it done? How thick of a layer is usually used over the concrete? Maybe sufficient just to concrete over it to seal it all up?

Pete,

In my experience sandwash is usually around 15-20mm thick and concrete floor 'screeds' (typically sharp sand, cement + (bonding/sealing) around 50mm thick, although there are different products now that can be laid thinner. Ironically we stopped using tiled pool steps (due to quick grout deterioration) and started sandwashing the steps and spa overflow 'ledges' and haven't known of a pool water deterioration issue in past 5 years, so maybe you're just unlucky to have had a 'bad mix'. Some more knowledgable may put some facts behind salt water effects on properly sealed sandwash, if any. Maybe deterioration is something we have yet to come in nexy few years, but I'd still sandwash again as could live with that maintenance every 7-10 years rather than group deterioration every couple of years!?!?

Sandwash steps/overflow may sound a bit naff to some but I actually think it looks more pleasing on the eye, plus never have slippery steps. Conversely if sandwash finish is not 'fine' it can be a mother to walk on for those of us without reptile-skinned feet...

xPhase 4_01.jpg (60.13 KiB) Viewed 2708 times

SJ

[PeteC]

Thanks SJ. Your photo is very similar to my setup concerning steps, and ledge from our baby pool into the big pool, plus we have a total overflow pool so I have a sandwash problem around the entire perimeter. I'm not going to shut things down until after school starts late August for the little one so she can use the pool until then.

There's really no way to get the sand out except to vacuum which makes me cross my fingers that my pump strainer basket is close knit enough to stop many granules from going into the pump. The pieces are pretty large and so far it's caught much of it. What it hasn't caught reappears around the edges of the floor water return ports. What the hell, with all this I may have to throw a new pump on as well, or fill the whole thing in with dirt and grow tomatoes. All I can do is

I'll update when I start something to document the what and how. Pete

[poosmate]

I have used sandwash in the same way as SJ on more than 30 pools over the last 8 years. I have not had any experience of deterioration and crumbling. I would suggest the water chemical balance has not been maintained correctly or the sandwash mortar mix was incorrect.
Fine sand and debris is best vacuumed to waste rather than recycled - Tip vacuum after the rain and correct the level at the same time.

[PeteC]

Thanks for the tips Poosmate. I'm pretty meticulous when it comes to testing and balance, so I'm leaning more towards the bad mix side. Good tip on the discharge vacuuming, I hadn't thought of that.

As I keep thinking, this may turn into a major renovation as I have a few cracked tiles and tiles stained by rust due to sala workmen dropping nails in and me not finding them before they left bad stains, some bad grout as mentioned, and the filter sand should be replaced soon. This model says 85-100 backwashes and it's close to that. Overflow holding tank needs draining and scrubbing, the plastic grating over the overflow trench is cracked in a few places....I think that trench looks better with stones in it as an alternative to the grating, nice to see/hear the water rippling over them. Let's see how close I can get to the cost of a new pool. Pete

[Nereus]

Didn't you get a structural warranty with the pool, Pete? Most constructors give a 10 year warranty on the pool itself, not including the pump and filter. What about the other houses on you estate? Have you asked around any of the other owners?

I tend to agree with the comment about the poor, or wrong, mix with the sand wash, added to the grouting. If you have tiles cracking I would be even more concerned about the overall quality of the construction, as opposed to a chemical balance problem.

A big problem whatever is causing it. Growing potatoes may be a better idea than tomatoes.

[Nereus]

I do not know anything about these bods Pete, but may be worth a phone call if they are still in business.

http://issuu.com/tcmasia/docs/sand_wash ... 9_englisch

[PeteC]

Nope, the standard coming out of the Pattaya pool makers at the time was 3 years on structure and 1 year on pump. We talked to three before making a choice. I've never heard of 10 or even 5 over here. Luckily I don't have big chunks coming out, yet, just the single tiny pieces of stone, but they add up. The tile cracking is minor hairline, it's just there on a few on a submerged ledge bench and I believe it was caused by the removal guys when we had a large tree go down into the pool during a storm. Grout is also minor, just a couple tiles on the floor, but the grout lines are not pristine white as when new but now stained. If I take the water out, I may as well get them fixed and all of the grout lines cleaned and sealed again. Actually, the pool is in good shape but I'm looking for things to address to bring all back to like new condition if indeed I have to drain it. I'm the only pool in this part of the development, about 100 houses. There's two big pools at the golf clubhouse and most people who buy/build here opt to use those. Thanks for the link. Pete

[PeteC]

As a followup, the water comes out next Tuesday at the start of a 15 day renovation routine. Sandwash steps and overflow area to be torn out and replaced with non-slip tiles, plus all the other things I mentioned above. I also opted to install some nice decorative tiles all around at the top edge water line. Will post a pic when completed. Pete

[JW]

Take a look at some sandstone, looks fab around the pool!

[hhfarang]

Would stamped concrete work in a pool application? I've seen it on driveways and patios in very interesting non-slip patterns.

[Takiap]

Yes, and it's a million times better than sandwash. There's a company in Bangkok that has a massive range of choices, and prices start at about 700 baht per square meter. Unfortunately I can remember the name of the company just now though.

[PeteC]

In for a penny, in for a pound. We've now decided to remove the entire 1 meter wide stonewash walkway around the pool. Everything that was stonewash being replaced with similar color sandstone non-slip tiles. If it looks like s@%t when finished, no photos. ...but I remain hopeful. About another 12 days to finish it. Pete

[PeteC]

My needed sandstone tiles still sit in a flooded warehouse in Rangsit. It looks like close to or after New Year before things are finished. Santa is giving us an ugly empty pit of a pool for the Holidays! Pete

[hhfarang]

Better put some stones or something else heavy in the bottom of it if it is really empty or it may rise out of the ground.