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