How to Install Rock Siding in a Log House

Cover all the surfaces where the siding will be installed with plywood sheets or OSB to provide a smooth surface for the rock siding. Hold each board against the log wall and drill it in place with 3-inch wood screws spaced every 12 inches along the edges of the board and down one line in the middle. Do not predrill the holes because these screws will not be visible.

Sand the entire surface of the plywood with rough grit sandpaper and wipe it smooth. Stretch out lath along the entire surface of the plywood. Drill 3-inch wood screws and plastic disk washers through the lath in a 12-inch grid, with the screws spaced every 6 inches along the edge of each lath section. Overlap the lath by 4 inches each time there is a seam, keeping the seams well away from the corners of the home.

Cover the lath with a 1/4-inch layer of mortar, getting it underneath the lath as well. Use the trowel to make the mortar smooth and then let it dry for two hours. Scuff up the surface of the mortar with a rake or scuffing implement. Let the mortar dry for 48 hours. Protect the mortar from rain if necessary with tarps.

Apply 1/4-inch of mortar to the rear of the rock veneers, one at a time. Set the veneers against the mortar, beginning at the top and working down, and press against the veneer for 60 seconds. Add larger rocks first and use the smaller ones to fill in the gaps later. Cut veneers if necessary with a saw to make them fit unusual spaces. Remove extra mortar that squishes through the spaces between stones.

Allow the stones to dry for a few hours and then add grout in between the stones to the desired thickness. Protect the stones from rain for at least 48 hours.