How to Build an Affordable DIY Concrete Fireplace for Cozy Winter Nights

How to Build a Concrete Fireplace

1. Remove Fireplace Insert and Facade

   Start by removing the existing fireplace insert. If the fireplace has a mantel, then this will also need to be removed. Next, check the fireplace to determine if it has facade. A facade is essentially a thin layer of material, like stone, that creates a decorative appearance for the fireplace.

   If the fireplace is made of plain, exposed brick, then you can move to the next step, but if there is a stone facade, then you will need carefully demolish the facade. Use a hammer and chisel or a demolition hammer to chip away the mortar and remove the stone facade, which should expose the brick fireplace.

2. Build Out a Fireplace Frame (Optional)

   Depending on the position, shape, and condition of the existing fireplace, you may want to build it out to give the fireplace a new look. You can do this by measuring the area, planning the shape, then cutting 2×4 boards to the correct lengths to build the intended frame.

   Use a drill and framing screws to put the fireplace frame together, then secure the frame to the brick using brick anchors. This will prevent the framework from shifting after the installation. Just make sure the framework leaves space to install the cement board.

3. Attach Cement Board and Tape the Seams

   Measure and cut the pieces of cement board using a utility knife. Once the cement board is prepared, begin mounting it to the brick or framework of the fireplace. Use cement board screws and a corded drill to secure the cement board.

   Next, use mesh tape to cover any seams in the cement board, then cover all corners with metal corner bead for a clean finish. You can attach the corner bead with the cement board screws for a secure fit.

4. Apply the Concrete Finish

   Grab a five gallon bucket and mix the cement as indicated by the manufacturer’s directions until the cement has a thin consistency, similar to pancake batter. Pour a bit of the mixture into the drywall tray and use the drywall knife to start applying the cement.

   Begin by apply the cement mixture to the tape seams, then gradually cover the rest of the cement board surfaces. Use long, even strokes to apply a thin layer of the concrete mixture.

   Generally, you will add about three to four layers of the cement mix. Follow the manufacturer’s direction to determine how long the cement needs to dry and fully cure. While the cement is still wet, you can use the drywall knife to smooth out the cement and get the ideal finish.

5. Sand and Seal the Concrete Fireplace

   Some people like the texture of the troweled cement, while others are looking for a smooth finish. If you want a smooth finish, then use a power sander to sand away a thin layer of cement to get the desired look.

   Wipe away any dust created by sanding the cement, then use a paint brush or paint roller to apply a sealer. The sealer will protect the cement from moisture and staining, increasing the durability and life of the fireplace.