20 Year Old In the Ground Pool with Tile Line Deck Issue starting to develop, question on options and materials

[murphy711]

Hi, I'm hoping to get some advice. We purchased a house with a 10,000 gallon in the ground pool with connected Spa. This year a problem developed where on the side of the pool between the pool wall and the hot tub, a gap is forming between the top of the deck and the top of the tile. I can see through the gap from the pool into the spa. When it rains this gap is almost gone then it opens back up. We have lived in the house for five years and this is the first time we have seen this. We live in the Chicago area. I called the company that built the pool 20 years ago and they offered to give an estimate to put in a new deck section. We don't want to do this due to cost, is there any material I can put in that will slow the damage or help the situation before it gets worse? I have some pictures to attach. I'm not sure if I should put something on the top of the deck ( picture attahced) or into the opening, or do nothing at this point. Appreciate any advice if you have seen this type of issue before. Thank you

 

[kimkats]

I am not sure but will call in someone who may know as he does this kind of thing for a living! @jimmythegreek

 

[jimmythegreek]

Hard to tell from pics but it looks like most of the tile grout is gone. Do you have a level? If so check the top to see how high that bulge is. Then check it after rain and see if it really is moving or just filling in so you cant see through it. That's a stem wall it should all be concrete so highly unlikely its moving and the top would be busted up worst than it is. The fix is to re grout and seal all the topside expansion joints ASAP. Water is your enemy and with winter approaching frozen water will do alot of damage. You need to go over the whole pool and seal anything letting water in

 

[murphy711]

Thank you both for looking into this. I put a level on this this morning and we have rain in the weather forecast.
The picture did not show the sections without the problem, there is no grout on top of the tiles , there is a white strip of very hard plastic ( not sure what it is called) that rests on top of the tile.