Loose Flagstone Coping

birdman579

New member
Dec 18, 2020
2
Maryland
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
I’m new to being a pool owner and have some questions on my coping stones. I have a 13 year old pool and raised spa in Maryland at my house I bought last year so I’ve only been through 1 pool season. I noticed the flagstone coping stones are loose and there is missing grout between some stones. They are not so loose they wobble significantly, but they have a hollow sound and the grout is coming loose. The pool and raised spa both have this issue.

What is the best way to re-set the stones? I would have thought mortar, but that only lasted 13 years which is not impressive. Should I use adhesive instead?

I also noticed there is no expansion joint between the coping stones and the paver pool deck. I assume I should add one when I re-set the coping stones? The lack of expansion joint probably caused the pool stones to come loose, but I’m not sure why the raised spa coping stones came loose as well. They cap the raised spa wall so they do not touch the pool deck.

Thanks in advance for the help!
 

keithw

Well-known member
Mar 30, 2007
312
Virginia Beach
take some pics and show them to us. Your flagstone were possibly not put down well in the first place and mortar/grout should work well to secure them back down. If there was a fracture line or a fracture line was created along where those stone are coming up then you probably need to work with that and mortar down what you can and silicone along the fracture line. The nice thing is you have years to figure it out so you cannot really do any harm by experimenting right now. Mortar and regout and see what happens next year. I use the same mix and color for the mortar and grout. Nice and easy.
 

birdman579

New member
Dec 18, 2020
2
Maryland
Pool Size
30000
Surface
Plaster
Chlorine
Liquid Chlorine
What do you mean by fracture line? Here is a picture of my pool from July (it’s currently covered in snow):
0075BD65-D170-4674-AADE-137500ED2C95.jpeg
I also included a picture of the one wall of the spa that is not good: cracked Pebbletec and it leaks.
975AFE9D-A906-4253-B6A4-54165435CF0E.jpeg

I imagine water got behind the Pebbletec due to the cracked grout in the cap stones or near skimmer and froze causing the finish to crack. I don’t have any of the issues in the main pool other than loose coping stones, but my concern is the pool could develop a situation like the spa.
 

bmoreswim

Mod Squad
Gold Supporter
Platinum Supporter
LifeTime Supporter
Jul 16, 2012
6,548
Central MD
Pool Size
27000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-15)
I don’t have much in the way of technical help, but I can show what your coping may look like below it and also why the design of your skimmer isn’t doing you any favors. In the two posts below from my build thread, you’ll see that in the straight on skimmer shot, the side of my skimmer are not exposed while yours are. That’s not correct. The tile should go up very close to the wier door/skimmer inner frame opening. Water could be gaining access there. Since your wall is raised, they put the skimmer in the coping. By doing so they created a grout joint above the skimmer. So there is no support below the grout to help keep it more solid.

In the second post, there is a shot of the coping being set. Our pool may have more mortar than most due to the autocover track being in there, but the point is to show you the potential volume of mortar below the stones. In my scenario, if my stones came loose and when I pulled them up, if the existing mortar bed was still intact, I’d use adhesive to attach them and redo the mortar between the stones. There will also be hairline cracks in the mortar at the stones and over time that can cause issues.

Bottom line is that 13 years for mortared coping in a freeze/thaw environment is probably not that bad. Our region can be worse than further north in that respect because we freeze and thaw possibly 75% of days in the winter.

As a side note, I’ve never seen a pool that had what looks like our tile (spoiler, I chose it but its not my favorite part of our pool), though I do love our bluestone coping, hot though it gets. Your pebble issue will require a big patch which will not come close to matching, or a replaster. Depending on your budget, you may at least think about giving your pool a makeover with new plaster, tile and coping, thought it’s probably a $20K job up here for pebble, and your pool is complex. You have reached the latter 1/3 of the common lifespan of pebble anyway. But I doubt you are excited about spending that kind of dough.

Just FYI, the company that did our coping was Arturo’s Tile and Coping 8 years ago.

https://www.troublefreepool.com/threads/pool-build-baltimore.53452/post-455889

https://www.troublefreepool.com/threads/pool-build-baltimore.53452/post-459108