On concrete block walls or unpainted brick walls the stone can be stuck directly to these surfaces without any additional layers needed.
On wood or drywall add a layer of tar paper starting at the bottom and working upward over laping the paper by 4″. The paper can be attached with a stapler because a layer of expanded metal lath is the next layer needed. This should be installed from the bottom working up and over lap by a couple of inches. Use nails or screws that will go into the studs by an inch and half. A tip here would be to add a washer to you nail or screw to help hold on the lath. Fasten the lath on every stud and not more than 8″ apart. Wear gloves to work with the lath it will chew up your hands as you work with it.
Cover the lath with a ½” coat of mortar or scratch coat and allow to dry for about an hour. When applying the scratch coat use a course brush to form grooves in the mortar so you next layer has something to grab on to. The mortar should be … Read the rest