Since having my 16x32 Vinyl IG pool installed last year, Ive started noticing little things in other pools I see. On about 80% of the pools I see, the concrete pool decking around the pool will have what I think are called, slab dividers, installed. They are usually wood or white vinyl strips place in the lines of the concrete. I see them used in other areas besides pool decking, but most of the decks around pools have them. I didnt have them installed in my decking, and am wondering what is the purpose of these dividers.
Are they cosmetic, structual, or what?