How to Install Rock on Plywood for a Mobile Home's Underpinning

Sand the entire exterior surface of the plywood to which the rock will be attached. Wipe down the plywood. Use the stud finder to mark the locations of the studs clearly along their entire length. Attach studs to the rear of the plywood if there are no studs already attached, affixing the studs to the plywood and the wood support beams of the mobile home.

Wrap lath around the plywood in long horizontal sheets, overlapping the lath by 4 inches if necessary when adding additional layers. Secure the lath in place by screwing it to the plywood tightly with 3-inch galvanized wood screws that are threaded through large plastic disc washers and then into each stud board in the plywood. Space the screws every 12 inches apart and keep the lath tight. Space the screws every 6 inches apart along the edges of the surface where rock will be applied.

Spread 1/4 inch of mortar over the lath and let it dry for 4 hours. Scrape up the surface of the mortar with a metal rake to get it ready for the stone application. Let the mortar dry for 48 hours.

Put 1/4 inch of mortar on the back of each stone veneer. Push the stone against the mortar surface, starting at the top of the wall and working down. Position each stone in place, cutting them with a saw when necessary. Remove any mortar that squishes out between the rocks. Let the rocks dry for 4 hours.

Add grout between the rocks, putting on whatever amount is desired for the specific rock look intended. Let the mortar and grout dry for 48 hours.