Separating coastal exposure from the actual surface problem
A Rancho Palos Verdes home may face the coast, but that does not identify a stain or etch. Note whether the concern occurs on a sheltered interior counter, a terrace edge or a surface beside planting. Photograph recurring water routes and describe how the area dries. A location-based explanation should not replace examination of the material and what has contacted it.
For exterior pieces, discuss the original texture and how the surface is used when damp. The preferred appearance is not necessarily the gloss of a neighboring indoor floor. Sealing may be appropriate for porous stone after assessment, but it does not create slip resistance, eliminate salt exposure or correct drainage. Avoid applying a strong cleaning product simply because a mark appears to be a mineral deposit.

