Gaping between mastic and tile

[TammyE49]

Within 3-4 months of water my pool slowly starting gaping between the mastic and the tile. We do have a cantilever deck. Our pool contractor said it was are fault because we are watering our
plants too much..which we are just watering to keep alive. So we actually believed it was on us. Now months later this gaping is happening on the opposite end of the pool, where there
is no landscape...all concrete decking then the house. Very concerned. Pool guy is coming out in a week to look at but we know he is going to says its normal.
We do have clay like soil. There is no visual cracking, concrete decking looks fine. Cannot see any lifting other than the spacing thats happening. Any same experience? I read about bond beam cracking but there is no visual cracking at tile or on plaster or concrete.

 

[zethacat]

Obviously if there are no plants on the other side where the same thing is happening, he is full of it.

 

[PoolESQ]

This is awful! Can you tell if the separation is caused by the pool dropping down or the decking rising up?

 

[TammyE49]

Facing the pool...concrete looks leveled...not rising at joints, buckled, or cracking. Tile water level looks lower..but not low..at that end (shallow). 1/4" diff from deep end.

 

[PoolESQ]

Sounds like a soil problem to me - improper compaction perhaps? I find it highly unlikely that watering your flowers is the cause of the pool sinking to this degree. Even if it is, the pool should've been built to withstand customary landscape watering. What you're seeing is NOT normal and don't let your PB get away without doing something to fix this issue at his expense. As to the proper fix? I'll leave that to the more experienced folks who I'm sure will be stopping by the thread soon to lend a hand.

 

[duraleigh]

Sorry to be dumb, but I can't figure out what has separated. What's the duct tape for? Is the separation between the waterline tile and the decking? If so, what's the white material I see?

 

[TammyE49]

Dont b sorry....picture used was pict from tracking water levels. Above tape...little bit of tile is I guess a mortar that has holes..then the grey mastic vertical strip

 

[PoolESQ]

Some PBs put that white plastic strip around the pool edge when pouring a cantilevered concrete deck. It's attached to the beam with liquid nails type glue. It could be that is the white material you see pulling away from the beam or it could be grout/mortar with holes. I'm not sure if the OP has checked for sure to see which of these two things it could be. The reason I thought it was glue is because it's white and the rest of her grout is grey. OP, might be helpful if you could post a couple more pics from further away to see the gap in perspective.

 

[TammyE49]

 

[ouachita]

The reason for mastic is so that it can flex when the different surfaces move because the movement is inevitable. It does not take much movement to do what you are seeing. If it were mortar or grout it would just crack or crumble out.

Whether you do it or the pool builder it just needs recaulked. If it were mine I would wait until it was at least a year old to repair it. My guess is the mastic was not applied thick enough in the spots it is pulling away.

 

[duraleigh]

+1 what ouachita said. Thanks for that MUCH better pic.

 

[Divin Dave]

Im not so sure your pool has sunk. I'm leaning toward what ouschita said.

If you measure the distance from the water to the top of the tile, at shallow end and deep end, it will give you an idea if the pool has sunk or not. I would doubt that it has though.

 

[PoolESQ]

Upon viewing the 2nd picture, I don't think your pool has separated or sunk, either. I'd follow his advice to add some more mastic in there.