How to Cover a Fireplace With Rock

Clean the dust and dirt off the rocks by lying then out in the driveway and spraying then off with the hose. Let the rocks dry completely. Cover the area surrounding the fireplace with plastic sheeting or a dropcloth to protect the floor. Push aside any furniture.

Put on a mask that covers your mouth and nose so you do not breathe in any dust. Clean the bricks on the fireplace with soapy water and a large wire brush. Scrape off any dirt and debris on the bricks. Vacuum the fireplace bricks to get all the dust.

Mix together a batch of thinset cement. Spread it across the bricks with a smooth trowel, pushing the cement into all the cracks and grooves. This give you a smooth level surface to work on. Let the thinset dry overnight.

Pour your cement mix in a large bucket and break up any clumps of the dry mix. Add water according to the directions on the bag. The resulting mixture should be as thick as cake frosting. Spread the cement mixture on the fireplace ½ inch thick with a hand trowel.

Spread a thin layer of the cement on the back and top of the rocks and place them in the bottom row. Press each rock into the cement using a small wiggling motion to secure the rock. Use enough force to squeeze some of the cement out from behind the rock. Leave a ¼-inch gap between the rocks and scrape any excess cement up with the trowel.

Spread the cement on the bottoms, tops and backs of the next stones. Continue to place the rocks in rows until you reach the top row. Do not spread cement on the tops of the rocks used in the top row. Do not pull on the rocks. Allow the cemented rocks to dry for two hours.

Wash your tools off and rinse out the bucket with water outside. Mix up your grout according to the package directions and spread between the rocks. Scrape any excess grout up with a craft stick. Wipe any grout off the rocks with a wet rag before it dries. Remove the plastic sheeting and allow the project to dry for at least 24 hours before touching the rocks. Let the fireplace rest for two weeks before lighting a fire.