Build Outdoor Fireplace With Cement Board

Tap the sides with a hammer to release any bubbles that may be trapped in the concrete.

Build outdoor fireplace with cement board.

Next you will build your firebox to whatever size you have chosen using firebrick and refractory cement from your local masonry supply. Nail gun nails drill screws chop saw shovel chimney cap protective gloves screwdriver masonry anchors or bits. 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. 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. Be sure to build it properly according to local codes. 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. 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.

Use screws to attach metal lath which is a wire mesh over all of the exposed cement board. The metal lath will provide support for the stone that will be placed on top. 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. 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.

The metal lath will provide support for the stone that will be placed on top. The door provides access to the burner controls. But on the metal surround use high heat adhesive to attach the cement boards. Using drill attach cement boards to frame with concrete screws.

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. We had a plan of attack. For smaller areas of frame use chop saw to cut cement boards to size.

You will want a minimum 4 thick up to 8 thick reinforced concrete pad. The concrete also needs steel reinforcement. Run a long flat board or concrete screed across the top of the concrete laying it on the board edges to keep the board level.