How to remedy flaking slate tiles in outdoor patio?

Question

My patio is covered but the outer rows of the tile get rain and some swimming pool water. These rows of tiles are deteriorating (flaking) and even turning to mud. When dry the surface is about a 1/4 inch down from rest of patio. Not sure if I can repair existing tiles with sealant or if they need to be replaced? If sealant is the answer, what prep do I need to do?

Answer 1

wire brush them top off with a water proof grout