When and How to Apply Granite Sealer

Granite sealer is a crucial part of maintaining granite surfaces. Because granite is a semi-porous material, unsealed granite can absorb water or grease, creating permanent stains. Granite sealer prevents this by penetrating deep into the granite and closing off its pores so that stains can't get in. Resealing your granite isn't difficult, and can be done well by even DIY novices. All you need is an afternoon, a clear, impregnating granite sealer, and a clean white rag.

When to Reseal
Many homeowners don't reseal until their granite starts to show stains. This is a mistake that can cause permanent damage. Instead of waiting to reseal your granite surface until you see spots of water or oil damage, seal your granite regularly to prevent these stains from ever occurring. To keep your granite effectively protected, you will need to apply granite sealer at least once a year. If your granite sees daily use, as many granite surfaces like kitchen counters do, the coating will wear off and leave your granite vulnerable unless you reseal every six months.

Sealer Application Basics
Start with a small area of about four square feet. As you master the two-step application process, you'll be able to seal a larger area at a time, but it is best to start small to avoid mistakes. Using your rag, coat the granite with sealer in a uniform layer that completely covers the area you're working in. This layer of sealant will penetrate deeply into the stone. Once you've wiped the area fully, give the granite sealer about four minutes to absorb into the granite's pores. When your sealant is almost fully absorbed and dry, apply a second, thinner layer. This layer will give you added protection on the surface, where your granite will see the most wear and tear. Complete this process until your entire surface, whether it is a floor or a countertop, has been sealed. Then, allow the sealant to absorb for at least a period of two hours before you continue with the job.

Finishing the Job
Once you've done a preliminary seal of your surface and let your sealant fully sink in, come back to your granite countertop or floor and do another full application of granite sealer, using the two step method described above. This will leave you with a total of four layers of protection on the delicate surface of your granite. If you are sealing a surface that sees very heavy wear, you may want to go over your surface one more time. When you are done, let your sealant dry thoroughly, and then do a spot check to make sure your stone is fully protected.

Testing Your Seal
Before you walk away from your sealing project, do a small test to make sure your granite is sufficiently protected against stains. For your spot test, pick an area of your granite surface that is out of the way, so that if it does stain due to insufficient sealing, it won't bother you in the future. To test your seal, spill a bit of water on the area. Leave the spill to sink in for thirty to forty minutes, and then wipe it up. If the stone in the spill area shows no visible changes, the water was not able to impregnate the stone, and your granite is sufficiently sealed. If the stone darkens, it means the water was able to penetrate your sealant. Dry the spot to reduce staining, then apply another coat or two of granite sealer over the whole surface, let it dry, and test again. Repeat until your test spot wipes up clean.