Arrange the manufactured stone on the floor in a pattern you'd like to replicate as the facing for your fireplace.
Staple the felt paper on the wall around your fireplace, using the staple gun. This will provide a vapor barrier.
Pour the dry mortar in a bucket, add water and stir with the paint stick according to the directions on the mortar package.
Staple the metal lath to the vapor barrier on the wall with the staple gun. Insert staples every 6 inches to secure the lath.
Smooth the mortar over the lath with the trowel. Cover the entire surface with a thin layer.
Apply mortar to the back of each stone and push them into the mortar on the wall, beginning from the top corners working down the wall.
Fill the grout bag with mortar. Squeeze mortar between each stone. Wipe off excess mortar with a rag. Let the mortar dry for a few hours, then sweep off excess mortar with the whisk broom.