Guide · 5 min read
Grout, sealing and the Coachella Valley's hard water
By Josh, owner & lead installer at Blue Diamond Tile & Stone · Published
Short answer
The valley's water is hard, and hard water leaves calcium scale on grout, tile and shower glass. Cement grout is porous and darkens unless it's sealed; epoxy grout doesn't absorb water and never needs sealing. Seal cement grout after installation and every year or two, clean with a pH-neutral cleaner, and use silicone — not grout — at every corner.
Why does grout go dark and crumbly in the desert?
Two causes. Cement grout is porous, so unsealed grout soaks up water, soap and dirt and darkens from the inside. And the Coachella Valley's water is hard — heavy in dissolved calcium and magnesium — so every drop that evaporates leaves a little scale behind. On shower floors that is a white crust over the joints within months; scrubbing it with acidic cleaners then eats the cement, and the grout crumbles.
A third cause looks like a grout problem but isn't: grout used in the corners where walls meet each other or the floor. Those joints move, grout can't, and it cracks. Corners get silicone caulk, not grout.
Which grout should you choose?
Three families, each with a place:
- Cement grout, sanded or unsanded: the standard, inexpensive, needs sealing; high-performance versions resist stains better
- Epoxy grout: non-porous, stain-proof, never needs sealing, best on shower floors and white joints; costs more and is harder to install
- Single-component or urethane grout: pre-mixed, stain-resistant, no sealing; a middle ground for walls and backsplashes
How often should grout and stone be sealed?
Cement grout: after installation, once it has cured, and every one to two years after — more often on shower floors and kitchen floors. Natural stone: the same schedule for the stone itself, with a penetrating sealer that doesn't change the finish. Porcelain and glazed ceramic tile don't need sealing; their grout does. A quick test: drip water on the grout; if it darkens within a minute, it's time.
What should you clean tile and grout with?
A pH-neutral tile cleaner for routine cleaning. For scale, a cleaner made for hard-water deposits, used as directed and rinsed — not vinegar on natural stone, which etches marble, limestone and travertine. Never bleach on colored grout, never abrasive pads on polished tile. A squeegee on shower glass after each use does more for scale than any product.
Fair questions
FAQDoes epoxy grout make sense in a Coachella Valley shower?
On the shower floor and anywhere you want white or light grout to stay that color, yes. It doesn't absorb water, so hard-water scale sits on top and wipes off instead of soaking in, and it never needs sealing.
How do I remove hard-water stains from tile?
With a cleaner formulated for calcium and lime deposits, applied, left for the time on the label and rinsed. On natural stone use only a stone-safe product; acid-based cleaners etch marble and travertine.
Why did the grout crack in the corners of my shower?
Because grout was used where silicone caulk belongs. Changes of plane — wall to wall, wall to floor, tile to tub — move with the house and need a flexible joint. We cut the cracked grout out and replace it with color-matched silicone.