Build Outdoor Fireplace With Cement Board

The door provides access to the burner controls.

Build outdoor fireplace with cement board.

The metal lath will provide support for the stone that will be placed on top. 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. On the ground and drywall use thinset and screws to attach the cement board. 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.

You will want a minimum 4 thick up to 8 thick reinforced concrete pad. Tap the sides with a hammer to release any bubbles that may be trapped in the concrete. There s a secret inside this outdoor fireplace. Move the board back and forth as you slide it across the concrete adding more concrete to fill in any gaps around the edges.

For smaller areas of frame use chop saw to cut cement boards to size. The metal lath will provide support for the stone that will be placed on top. Using drill attach cement boards to frame with concrete screws. But on the metal surround use high heat adhesive to attach the cement boards.

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. Be sure to build it properly according to local codes. I suggest 4 solid block for this purpose. 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.

The concrete also needs steel reinforcement. Nail gun nails drill screws chop saw shovel chimney cap protective gloves screwdriver masonry anchors or bits. Use screws to attach metal lath which is a wire mesh over all of the exposed cement board. We had a plan of attack.

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. Cut cement board to size using chop saw. To build an outdoor fireplace make a detailed plan of what the fireplace will be for where it will go and what will go around it.