Granite, marble and quartzite are porous natural stones that benefit from periodic sealing. Here is why sealing matters, how often to do it, and a simple test to know when yours needs it.
Why Natural Stone Needs Sealing
Unlike nonporous quartz or porcelain, natural stones like granite, marble and quartzite have microscopic pores that can absorb liquids. Left unsealed, a spilled glass of red wine or a drizzle of olive oil can soak in and stain. A sealer fills those pores and buys you time to wipe spills up before they penetrate. It does not make stone stain-proof, but it makes it far more forgiving.
In South Florida's humidity, sealing also helps stone resist moisture and the dark spotting that can develop around sinks and faucets.
The Water Test
Not sure if your stone needs sealing? Do this quick check:
- Pour a small puddle of water on the counter, about the size of a quarter
- Wait 15 to 30 minutes
- If the water beads or stays on top, your seal is still working
- If the stone darkens where the water sat, it has absorbed in and it's time to reseal
Different stones drink at different rates. A dense quartzite may go a year or more between sealings, while a soft, absorbent marble may need it more often.
How to Seal in a Few Simple Steps
Sealing is a straightforward job most homeowners can do themselves with a quality penetrating (impregnating) sealer:
- Clean the surface with a pH-neutral cleaner and let it dry fully
- Apply the sealer evenly with a clean cloth, following the product directions
- Let it soak in for the specified dwell time, usually 10 to 15 minutes
- Wipe off all excess before it dries to avoid a hazy film
- Apply a second coat if recommended, then avoid using the counter for a few hours
How Often and What to Avoid
As a rule of thumb, reseal granite and quartzite once a year and marble every 6 to 12 months, but always let the water test be your guide. Between sealings, protect the stone by avoiding acidic and abrasive cleaners. Vinegar, lemon, and harsh chemicals break down sealer and can etch the stone itself, especially marble.
Stick to cleaners labeled safe for natural stone, and always use coasters and cutting boards. Explore your options on our granite, marble and quartzite pages.
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Request a Quote Browse Natural Stone OptionsFrequently asked
How often should I seal my countertops?
It varies by stone and use. Test yearly and reseal when water no longer beads. Granite and quartzite often go about a year; softer marble may need sealing every 6 to 12 months.
Do quartz and porcelain need sealing too?
No. Quartz, porcelain and sintered stone are nonporous and never need sealing. Only natural stones like granite, marble and quartzite do.
Can I seal the stone myself?
Yes. With a quality penetrating sealer and a clean cloth, sealing is a simple DIY task. Just wipe off all excess before it dries to avoid a hazy residue.