How to Add Faux Stone to a Fireplace

Attach waterproof paper to the fireplace frame with a staple gun. The material should wrap entirely around the frame and overlap on the joints by 4 inches to create a tight seal. Trim the excess with snips.

Attach the metal masonry mesh to the entire surface of the fireplace frame using galvanized nails and a hammer. Hammer the nails securely into the studs behind the fireplace frame, placing a nail about every 6 inches. Place each nail so that the head catches a corner of the mesh pattern. Trim the excess with snips.

Lay the fireplace frame template on the floor in front of the fireplace. Arrange the faux stone on the template to determine the most pleasing placement. Move the faux stone around until you have an appealing variation of colors, patterns and sizes. Keep the joint spacing at a consistent 1/2 inch throughout the pattern.

Cut any stone that overlaps the fireplace frame template by using a circular saw equipped with a diamond blade.

Place mortar mix in the bucket or wheelbarrow, adding water until it is the consistency of cake batter. Mix with a stirring stick until the mixture is smooth. Note the ratio of water to mortar mix so that each batch is mixed to the same consistency.

Spread the mortar with the masonry trowel about 1/2 inch thick on the top left corner of the fireplace frame. Cover enough area to place two to three stones.

Lift the first stone off your frame template and spread mortar on the back of the faux stone with the masonry trowel. Place it in the corresponding spot on the fireplace frame, pushing the stone firmly into the mortar mix so it secures to the masonry mesh below. Some mortar should push out from beneath the faux stone when this step is accomplished correctly.

Hold the stone in place for about one minute until the bond is secure. Use a cordless screwdriver to drive a screw below the stone and in the joint area to further reinforce the placement until the mortar dries.

Continue applying mortar and placing stones until the entire fireplace frame is covered with faux stone. Work from the top down.

Remove all the holding screws with the cordless screwdriver when the mortar is sufficiently dried to hold the faux stone in place without support.

Mix another batch of mortar mix in the same container as the first, creating a thinner consistency than before. Test the consistency by filling a grout bag with the mixture and squeezing it back into the bucket or wheelbarrow. The grout mixture should easily squeeze out the opening of the grout bag without the use of undue pressure. Note the ratios used in case another batch is needed later in the process.

Fill the grout bag with the grout mix. Fold the top of the bag down several time to keep the grout mix inside and create adequate pressure at the bag's tip.

Squeeze the grout mixture evenly into the gaps between the faux stone, beginning at the top of the fireplace frame and working downward. Fill all joint areas on the entire frame with grout mixture, refilling the grout bag as necessary.

Allow the grout mixture to dry until the material is firm, but still has some moisture.

Level and compact the grout in the joints using a small wooden stick, scraping off high spots and creating a firm bond between the faux stones. Allow the grout to dry completely.

Clean off all loose mortar and grout using a whisk broom.