How often should you deep-clean and reseal your tile grout?

Why bother

Worn sealer lets the grout drink water and grow mold. A thorough-tier job. Skippable when life's busy, worth it when it isn't.

Why it's a range

It flexes with how wet and busy the room is. A family bathroom or shower that gets used hard wants doing about every 12 months; a guest bath or a low-traffic floor is usually fine at 18 to 24. The water-bead test settles it: drip a few drops on the grout, and if they soak in instead of beading, it's due whatever the calendar says.

What the job involves

1. Scrub the lines clean first. Make a paste of baking soda with a little dish soap and warm water (or baking soda and hydrogen peroxide), let it sit 10 to 15 minutes, work it in with a stiff brush, then rinse and wipe.
2. Let it dry fully. Surface dry won't do. Give cleaned grout up to 24 to 48 hours so the sealer can actually soak in instead of sitting on top.
3. Brush a penetrating sealer onto the grout lines with a small brush or an applicator-tip bottle, wiping any sealer off the tile face within a few minutes. Most jobs want two coats, a few hours apart.
4. Keep it dry and out of use while it cures, usually 24 hours, before showering or heavy traffic. Spot-check it yearly with the water-bead test.

Do it yourself, or pay someone?

Yourself, for most homes. The hard part is patience, not skill: clean, dry, brush sealer onto the lines. A bottle of penetrating grout sealer runs about $10 to $40 and covers 200 to 1,000-plus sq ft, and doing it yourself saves roughly $110 to $140 over hiring out, says Angi. If you'd rather not, professional sealing on its own is about $0.25 to $1.50 per sq ft, around $150 to $250 for a small bathroom, or $0.75 to $5 per sq ft bundled with a deep clean.

What skipping it costs

$200 to $1,200 is the partial regrout or grout replacement waiting at the end of this, going by Angi's 2026 numbers. Cement grout is porous, so once the sealer wears off it soaks up water and grime, stains for good, and starts growing mold in the lines. Left long enough the moisture works under the tiles and you stop cleaning grout and start a full shower regrout, $600 to $2,500, or a retile at around $2,620, more than three times the cost of regrouting. A $10 to $40 bottle of sealer is the cheap end of that ladder.

Signs it's overdue

• Water no longer beads on the grout. Drip a few drops, and if they soak straight in instead of sitting up, the sealer has worn off and it's due.
• Grout darkens fast when it gets wet, stains are getting harder to scrub out, or the lines just look dull and dingy.
• Grout that's cracking, crumbling, or going soft, or a musty smell and dark mildew in the lines. That means water is already getting behind it.

When to start thinking about it

A few days' warning does it. Grumpty grumbles 5 days out, then leaves you alone. Mark it done and Grumpty sets the next one, every 12 months, so you can go back to forgetting it exists.

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