Stone Coping Motar Joint

awhering

New member
Jan 2, 2018
4
Waxhaw
Hoping I can get some opinions or photos of flagstone or stone veneer coping. Pool builder started ours and when we saw the large mortar joint we had them stop and rip it up. Any advice on if this is normal? Thanks
3F15ACB5-C88A-436B-9000-19DC13E2457E.jpg
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,843
Tucson, AZ
I can shoot some pics later if ours but our mortar joints are wide, a good 1” easily. With hand cut FS, you’re not going to be able to get tight mortar joints. If you want narrow mortar joints, you’ll need precast coping or something like travertine coping.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
11,303
Bedford, TX
A,

Welcome to TFP... a great place to find the answers to all your pool questions.. even if you are ashamed of the State you live in.... :shark:

Are you talking about the spacing between the stone and the tile.. or the spacing between each stone?

What is it that you expect???

Thanks for posting,

Jim R.
 

awhering

New member
Jan 2, 2018
4
Waxhaw
Thanks for your reply. I was referring to the spacing between the tile and stone..seems like it is much larger than I’d expect. I wasn’t home to see the coping job however I’d also expect the stone to overhang on the pool 1-2” which would hide most of the mortar
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,843
Tucson, AZ
My mortar bed is easily that thick. Our overhang is minimal to avoid head bumps. Rough cut flagstone can be quite sharp and if you wanted a big overhang, it would be better to grind it smooth and rounded.
 

awhering

New member
Jan 2, 2018
4
Waxhaw
That is helpful. Do you have a picture of yours? Would like to see what the finished product looks like. Thanks again!
 

PoolGate

Gold Supporter
TFP Guide
Jun 7, 2017
2,777
Damascus, MD
Thanks that is helpful..still hoping to see if anyone else has natural veneer flagstone and what theirs looks like.
It has to do with order. They should have put in the flagstone first and then the waterline tile. You can look at my sig-pic link to see the order in which they installed it.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
11,303
Bedford, TX
It has to do with order. They should have put in the flagstone first and then the waterline tile. You can look at my sig-pic link to see the order in which they installed it.
pg,

I believe it has more to do with the material.. Natural stone is not flat, so it has to be set into a thick bed of mortar. Man made products are more consistent, so the 'gap' can be smaller..

Thanks,

Jim R.
 

PoolGate

Gold Supporter
TFP Guide
Jun 7, 2017
2,777
Damascus, MD
pg,

I believe it has more to do with the material.. Natural stone is not flat, so it has to be set into a thick bed of mortar. Man made products are more consistent, so the 'gap' can be smaller..

Thanks,

Jim R.
I agree but if they put the stone on first, they can bring up the tile to the mortar bed. That's how mine was done and there is no gap at all.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
11,303
Bedford, TX
I agree but if they put the stone on first, they can bring up the tile to the mortar bed. That's how mine was done and there is no gap at all.
pg,

I believe that is because the bottom of your coping is level... so you can push the tile up against the coping. I don't believe that you can do that with irregular shaped coping, like flagstone..

Thanks,

Jim R.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,843
Tucson, AZ
Here’s an interesting spot in my pool coping where the mortar bed is a different thicknesses (this is only in one spot and it’s a extreme example) -

D72D97BB-6AE4-4CA2-913D-34617B8D349A.jpg

The flagstone is 3” thick, hand cut and no grinding. This is where the mason used a piece where one end was thinner but made up the difference in the mortar bed so that the top surface is level.
 

sehrmude

Bronze Supporter
Aug 21, 2017
191
Tampa, FL
This seems like a no-win situation.. Since you have square waterline tile, if you push the tile up to the coping, the tile will not be even. If you set the natural flagstone even with the tile, the top of the coping will not be even. The way the PB had it, with the top of the coping (pretty much) even, the gap in between can't be even.

While just about anything can be done, how much are you willing to spend to have it your way? Pay someone to carefully grind every coping stone flat on the bottom side and to even thickness...
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,843
Tucson, AZ
Just as a note - my tile line was set first for leveling and setting the waterline and then the coping was placed relative to that.

I think it has A LOT to do with the quality of the starting material and the skill of the craftsman. My flagstone is Arizona FS (natural buckskin color) and it is very uniform in thickness and surface smoothness. That shot that I put up is the only piece of FS in the entire pool where one end of it was about an 1" thinner than the other side and thus required the mortar bed thickness to vary as much as it did (it's also placed in an area of the pool that no one would really see so it doesn't mess up the visual appeal). Other than that one piece of FS, the rest of the coping pieces are 3" all the way across +/- 1/4". The mason also spent a lot of time hand chopping the FS pieces and fitting them together so that the mortar lines are only about an inch wide or so. These guys were real pros and had all the mason tools (different mallet weights, stone chisels, etc) to do the job. They did not use any power tools, everything was hand cut.

I will say the one picture in the original post makes it look like the material used is not very high quality in terms of surface parallelism - either the type of flagstone used just doesn't produce smooth fractures along the bedding plane or the supplier of the flagstone did a poor job splitting the pieces. Flagstone material can be highly variable and it depends a lot on where it comes from. We have very good flagstone here in Arizona that is both very durable and visually appealing.
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
37,390
Tallahassee, FL
Are you saying they have already removed it when you say "we had them stop and rip it up"? What did they say and how do they think they can do it the next time?

If the mortar were a lighter color that would be helpful. I think you may be happier with a man made product or higher skilled workers that are willing to go the extra steps like joyfulnoise's workers.
 

Meadow

Well-known member
Jun 10, 2016
477
Temecula, CA
Our 18 yr old pool was remodeled a couple of months ago, new coping, tiles and plaster. I think the original coping is called flagstone or sandstone and it flakes too easy. Not a single flaw with the existing tiles but according to PB, it has to go when replastering. I would say, PB engaged professional subs and they completed the project in the order as PoolGate stated in his post....coping, tiles then plaster. We agreed to go with Quartzite coping although I'm not really sure if that is what we have installed now.

The stone varies in thickness when delivered but workers tried their best to match the stone in groups. The strategy is to break the big chunks and install them next to each other. Same thickness goes inside, thin or odd size outside. Coping sits on top of the wooden plank (waterline tiles width) to maintain level as shown in the pic. It was a laborious process and took 6 days for 3-4 workers to complete the coping. Hope this helps!

Here's how it look before:


Quartzite coping installation:


NPT GemStone Blue Tile/ InyoPools 12V LED's installed by your humble servant :whoot:




 
Last edited:

RoyR

Bronze Supporter
Jul 31, 2018
122
Escondido/CA
Do you know what grout / color they used?

Our 18 yr old pool was remodeled a couple of months ago, new coping, tiles and plaster. I think the original coping is called flagstone or sandstone and it flakes too easy. Not a single flaw with the existing tiles but according to PB, it has to go when replastering. I would say, PB engaged professional subs and they completed the project in the order as PoolGate stated in his post....coping, tiles then plaster. We agreed to go with Quartzite coping although I'm not really sure if that is what we have installed now.

The stone varies in thickness when delivered but workers tried their best to match the stone in groups. The strategy is to break the big chunks and install them next to each other. Same thickness goes inside, thin or odd size outside. Coping sits on top of the wooden plank (waterline tiles width) to maintain level as shown in the pic. It was a laborious process and took 6 days for 3-4 workers to complete the coping. Hope this helps!

Here's how it look before:


Quartzite coping installation:


NPT GemStone Blue Tile/ InyoPools 12V LED's installed by your humble servant :whoot:




 

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