Sealing granite countertops is a great thing to know if you have just purchased one or inherited one with a new home. Many new granite countertop owners are unaware of the porosity of granite and how easily the stone can be stained if the proper measures aren't taken to seal it properly.

If you have recently purchased a new home with granite countertops or purchased new ones for your existing home, you probably don't need to worry about immediately sealing the stone as it was likely done following installation. To be on the safe side, however it's best to be sure. Either pour a little water on the countertop and allow it to remain for a few minutes or soak a dish towel and lay it on the countertop. Dry the water and the area where you placed the dish towel; if the stone appears darker in color than the stone around it, it's wet. It's a sure bet that the granite needs to be sealed.

As a general rule, granite countertops should be sealed twice a year, but the frequency can vary depending upon how often the area is used. Frequently used surfaces may require resealing as often as every four to five months.

However you choose to seal your granite countertops, it is important to do so if your water test indicated they need it. The finish must be protected from standing water, grease and the more caustic solutions, such as chemical cleaners, orange juice and coffee. Any kind of acid can break down the sealant and leave the granite exposed to stains.

Following are the steps to follow when sealing:

1. Clean the entire surface of your countertops with a mild solution of dishwashing liquid and water and allow the granite to dry thoroughly. Most sealant manufacturers recommend a full 24 hours after cleaning before applying the sealant.

2. Choosing about a four square foot area to work with, apply the sealer uniformly with a clean, soft cloth or paint brush, applying the amount of sealer recommended by the manufacturer. Work quickly to apply the sealant to the entire countertop.

3. Allow the sealant to absorb the liquid for approximately 20-25 minutes. (Refer to the directions on your sealant container for the exact time as times vary between manufacturers.)

4. When the time is nearly up and the sealer is almost dry apply a little more sealer to the granite and work it in with a clean dry cloth to a shine. If you desire to apply a second coat of sealer, wait at least three hours.