Coping Tile Lifting Up

[Rxinverstor]

Hi Everyone
Just noticed two pieces of my coping tile are starting to lift up from the pool. These two just so happened to be located about the skimmer.
I’ve attached a photo. Any thoughts on what might’ve caused this and suggested next steps?

thanks!

 

[ajw22]

Show us wider pics of that coping area.

Is the tile physically loose or you just have an open joint?

 

[mmardini]

That happened to us but we had a gigantic palm tree right next to the area. We had the tree removed and had the pool resurfaced and they took care of the gap with some kind of cement. I’ll attach pics of how it looked after fixed

 

[mmardini]

Here are pics of what they did to fill in the gaps

 

[Rxinverstor]

Thanks for the responses.This is the only tile where this is happening. Not sure if being over top the skimmer is playing a role. You can see the tile has lifted up about 3/8 inch. I can push it right back down but it just lifts up again. I can't seem to get a better picture with getting in the water which is frigid now. I called the contractor who installed the tile to come take a look. He was quick to point out that I'm out of warranty now...

 

[ajw22]

Take wider pics of the coping from the top showing the deck area around it.

I think your skimmer may have dropped, not the coping lifted.

Or the soil under your deck is expansive and lifted it.

 

[JamesW]

Note that the tile is the blue ceramic/glass at the waterline. The coping is the White stone on top.

Is there an expansion joint behind the stone?

When was the pool installed?

 

[Rxinverstor]

Note that the tile is the blue ceramic/glass at the waterline. The coping is the White stone on top.

Is there an expansion joint behind the stone?

When was the pool installed?

Yes there is an expansion joint. The pool was built in Feb 2017. I snapped a few pictures from above. You can see the coping is lifted slightly just left of the skimmer lid.

 

[JamesW]

I don't see a good expansion joint. The expansion joint should be about 1/4" to 3/8" and very uniform. The expansion joint needs to be filled with a good expansion joint caulk.

In my opinion, the expansion joint needs to be saw cut and done correctly to allow the deck to expand and contract without pushing on the coping.

The buckling looks like it is due to horizontal expansion of the coping stones. It looks like one coping to the left of the skimmer is cracked. If the stones were grouted when they were cold, they would be at minimum width. When they heat up and expand, there is nowhere to go. The grout should be done when the coping is hot and fully expanded. That way the grout would tend to separate in hairline cracks instead of compression problems like you are seeing.

In addition to saw cutting the entire expansion joint, I would suggest that you do some thin relief cuts at the grout joints and regrout when the coping is hot. Do this right before the weather starts to warm up and then grout on a hot day.

Check all of the stones by tapping lightly with the plastic end of a screwdriver to see which stones sound hollow. The hollow ones are unbonded and need to be taken up and reset.

 

[Rxinverstor]

Thanks for this James. Couple of additional questions as this will be my first time messing with coping tile.

1. Do I use thin set mortar to adhere the coping to pool?
2. What type of grout is used for this application?

 

[JamesW]

1. Do I use thin set mortar to adhere the coping to pool?

Thin set should be fine.

2. What type of grout is used for this application?

You can use a colored sanded grout from Lowe's or Home Depot that matches the color of the existing grout.

 

[Rxinverstor]

Sorry, one last question. My extra tiles are 24". The cracked tile I need to replace is 21.5". I'm imagining I need a special saw and blade to make a precision cut of this nature?

 

[JamesW]

https://www.lowes.com/pd/Kobalt-7-in-Wet-Continuous-Diamond-Saw-Blade/3151529

I would suggest a continuous diamond saw blade. A wet cut is preferred but you can do it dry.

 

[Rxinverstor]

So I’ve pulled up the two tiles and am in the process of grinding off the old thin set. I’m assuming I need to get this area about 1/4 inch lower to budget for the new thin set so as to make the tiles level.
Is that the correct approach?

 

[JamesW]

You need to remove the old mortar that is loose or that is too high so that when you reset the coping, you have room for the mortar and stone to sit flat.

 

[Neto]

looking at your pictures, if you remove too much of the existing mortar it could damage the waterline tile.. Try using a chisel and get at least 1/4"-1/2" out.

 

[jimmythegreek]

You can eat some of that away with an angle grinder amd diamond wheel. You could also make some scarifying Mark's to add in adhesion of thinset for more bite. Easiest way for a DIY repair cut is to make a template amd use that for the cut. Many lowes, etc will cut tile for you for a small fee. Just be sure of the size many times they are not actually perfectly square cut

 

[Rxinverstor]

Replaced one of the two tiles and reset them both in place. Worked out nicely. Appreciate the help from everyone. One last item I need to attend to is there is about a 1/4 inch gap from the top of the skimmer head to the coping tile. Can I use a basic silicone sealant from home depot or is there a better flexible sealer for this issue?