There are two independent structures in the swimming pool, including the pool and pool deck.
These structures are connected by means of mastic joint which are installed to allow for expansion of the pool. The mastic joint, which surrounds the pool do crack so you need to find ways to seal it as quickly as you can. Why should you care about sealing the mastic joint?
When mastic joints become weak they allow water into the concrete which leads to soil or deck movements that can cause major issues in the future.
Using a pool mastic is one of the most effective ways to help seal leaks and make the pool function properly. You should avoid making use of any other kind of sealant like sand etc. because they do not have the properties that pool mastic has – which is the ability to expand and contract without leakage.