If you got concrete for your pool decks, the appearance of thin shallow cracks might not worry you a bit. Most designers and concrete installers would treat them as a normal flooring part. And if one intends to fix that, a sealing method would occur.
Pool Deck Replacement: When it tells you it’s time
Certain types of damages would get resolved with standard methods of repair. But a replacement would be a different scenario since you would have to tear the entire flooring material away. So what telltale signs say it’s time for resurfacing with new material?
Growing Cracks
Algae/Mold Growth
Algae and mold growth should worry you. Do not undermine seeing growing green specimens inside and outside the swimming pool.
A mold on the pool decks may be washed away easily with pressure washing the surface. However, when the mold keeps on coming back, a mold and algae type of infestation may already have existed. That needs replacement to totally prevent the bacteria and the tiny living organisms from breeding on the surface and the core of the slabs.

Pool of water emerges on the decks
Pool water should be on the basin or the concrete interior of the swimming facility.
Water shouldn’t be collecting itself on the decks. If you see that happen, it means that the decking material has deteriorated.
A severely damaged slab accompanies the watery surface, probably leading to the slab breaking apart. A crack filling or patching will not do it any better, and replacement is what you will need for this type of damage.
Peeling of the Paint

This next sign will tell you that a replacement is necessary for terms of the outermost layer of the slans. That means you will need to change the entire sealer of the concrete decks. It will involve applying another layer of a new compound, but you will need to prep the flooring into a fresh slab. That will include stripping off old coatings and residues of the old ones.
The chipping paint needs to be completely peeled off without any traces. Once the slab is clean and clear, you can repaint or reseal the top layer of the decking, looking brand new.