Grout Repair and Sealing on Long Island

Yes. Inside corners should be silicone, not grout. We replace them with color-matched silicone where needed.

Cement-based grout should be sealed at install and re-sealed every 1–2 years in wet areas, every 2–3 years in dry areas. Epoxy and urethane grout don’t need sealing. We can tell you which kind of grout you have during the visit.

Three usual culprits: it’s unsealed (or the seal has worn off), it was installed too soft (under-mixed), or the cleaner being used is acidic and is dissolving the grout. We can identify which and fix it — sometimes a deep clean + re-seal solves it without regrouting.

Grout itself isn’t the waterproofing layer — the membrane behind the tile is. But sealed grout is much more resistant to staining and water absorption. In a properly waterproofed shower, sealed grout is just the visible top layer of a watertight system.

It’s usually a cosmetic issue rather than a structural one — but if it keeps coming back after cleaning, it can indicate moisture getting behind the tile, which is a bigger problem. We’ll check for that during the estimate.