How to: Stone Veneer Exterior Porches

Sand each section of the porch, including posts, walls and supports using rough grit sandpaper. Drill holes in the wood of the porch in a 12-inch grid covering every surface. Drill the holes every 6 inches along the corners of walls or the edges around windows.

Stretch sections of lath over every surface of the porch which will have stones set against it. Use the tinsnips to cut the lath as necessary, but use the longest pieces of lath possible to ensure the fewest number of seams, which should overlap by at least 4 inches. Align the seams of the lath so that they fall on flat sections of walls and posts and never on the corners.

Drill galvanized 3-inch wood screws with plastic disk washers through the lath at each hole position. Add additional screws at any sections of the lath which need to have further support, such as overlapping seams.

Cover the entire porch surface with mortar so that it completely integrates in the lath, covering each seam and getting underneath every section. Apply the mortar with a trowel and keep it smooth and even until it is more than1/4-inch thick on top of the lath. Work from section to section and only move on once a section is complete.

Let the mortar dry out for three hours, then scrape the surface of the mortar with a rough, sharp object like a metal rake or pitchfork. Scrape all the mortared surfaces to prepare the mortar for the addition of the veneers. Let the mortar dry for 48 hours and watch carefully to make sure it doesn't get wet by covering it up with tarps or paint cloths if necessary.

Smear 1/4-inch of mortar on the backside of each stone veneer and fix it to the porch by holding it in place for 30 seconds. Do the stones at the top of the porch first and work down. Use big stones at first and use any remaining smaller stones to fill in gaps left by the large stones. Cut stones as needed to make designs or fill in unusual gaps which cannot be filled with normal stones.

Let stones dry for three hours then insert grout between the stones to whatever depth of grout is desired. Keep the porch area dry for 48 hours to let the stones set in place firmly.