How to Seal a Flagstone Patio

Everybody loves the look of a new flagstone patio when the colors of the stone are vibrant.
However, after a while, the flagstone appears to lose its color and become gray. That is a part of the natural chemical reaction of the flagstone to the elements. Cut from larger rocks, the new stone surface has not yet acclimated, when it does, it can become dull. Sealing a flagstone patio helps to keep the colors vibrant. The process is easy and can be done in about two hours.

Step 1

Sweep the flagstone to remove any debris. Remove any furniture, plants, toys or anything else from the stone patio as well.

Step 2

Open your color enhancing stone sealant and pour it into a paint tray.

Step 3

Use your paint roller to apply the sealant to the stone. Make sure you begin in a back corner and then work back and forth across the patio, so you do not miss any spots and do not paint yourself into a corner.

Step 4

Let the sealant dry (check the manufacturer's suggest drying time on the can). Then reapply the sealant. You will want a minimum of two coats, but if you live in an area that has a much longer "patio season," like in the south or south west, apply a third coat. Make sure the coats are completely dry before replacing your patio furniture and anything else on your patio.

Things You Will Need

  • Broom
  • Color enhancing stone sealant
  • Paint tray
  • Paint roller


  • Unscrew the handle from the broom and use it as an extension for the paint roller so you can apply your flagstone sealant while standing upright, this will be much easier on your back.


  • Avoid using urethane based sealants. While cheaper and providing an initial high "wet-look" shine, they cause a chemical reaction within the stone that will make the surface look mottled and gray in about a month.

About the Author

Cassandra Tribe has worked in the construction field for over 17 years and has experience in a variety of mechanical, scientific, automotive and mathematical forms. She has been writing and editing for over 10 years. Her areas of interest include culture and society, automotive, computers, business, the Internet, science and structural engineering and implementation.