Build Outdoor Fireplace With Cement Board

The metal lath will provide support for the stone that will be placed on top.

Build outdoor fireplace with cement board.

On the ground and drywall use thinset and screws to attach the cement board. Nail gun nails drill screws chop saw shovel chimney cap protective gloves screwdriver masonry anchors or bits. For smaller areas of frame use chop saw to cut cement boards to size. If you are building on a pre existing concrete pad or one much larger than your fireplace footprint be sure to form or cut expansion joints around the fireplace.

There s a secret inside this outdoor fireplace. This outdoor fireplace looks like a solid concrete cube but this hollow box holds a standard propane tank and regulator the same components that fuel a typical gas grill. We had a plan of attack. Once your concrete footing has cured for 24 hrs or more you will need to build a level base on which to construct your firebox.

The concrete also needs steel reinforcement. Using drill attach cement boards to frame with concrete screws. Add cement board to the entire area you ll be tiling for us that means the floor and all 4 sides of the fireplace leaving room for wood mantle. The door provides access to the burner controls.

Next you will build your firebox to whatever size you have chosen using firebrick and refractory cement from your local masonry supply. Be sure to build it properly according to local codes. Just remove the burner and lift out the tank when it needs to be refilled. Use screws to attach metal lath which is a wire mesh over all of the exposed cement board.

Once you know what you want to build lay a concrete foundation put a layer of cinder blocks over that then build the firebox and chimney out of firebrick and use a jointer and brush to remove bubbles from the mortar. But on the metal surround use high heat adhesive to attach the cement boards. The metal lath will provide support for the stone that will be placed on top. Cut cement board to size using chop saw.

Move the board back and forth as you slide it across the concrete adding more concrete to fill in any gaps around the edges. Tap the sides with a hammer to release any bubbles that may be trapped in the concrete. I suggest 4 solid block for this purpose.