Q&A: How frequently do I need to reseal my granite kitchen countertops?

My contractor told me I should reseal my granite countertops periodically to protect them from stains. How do I know when it's time to reseal them?

Granite, limestone, and marble countertops are all different, so check with the fabricator to see what the recommended time period for resealing is. But if your kitchen countertops get a lot of use, the general rule of thumb is to reseal them every six months, according to Andy Graves, of the Fabricator Network trade group. Graves suggests you do a water-absorption test to get an idea of how fast water is penetrating the stone and whether the counters need resealing.

To test, put a few drops of water on the stone in high-use areas, such as around the sink and range or cooktop, and let the water stand for 15 minutes. The water should bead up. If it doesn't, it's time to get the granite resealed.

You can also use this test on butcher block and other wood countertops that have an oil finish. You do not need to reseal a wood counter with a polyurethane finish, however when this finish is worn or damaged, repair or refinish it. —Kimberly Janeway | e-mail | Twitter | Forums | Facebook

Essential reading: Read our latest report on countertops and check out the ratings (available to subscribers) to find the best material for your home. If you're remodeling our kitchen, use our updated Kitchen-Planning Guide.