How to Build Mortared Stone Walls

Pour a foundation. Working with a helper, snap a chalk line on the footing outlining the front and rear faces of the wall. At each end of the wall, lay first course of both wythes, a bondstone that is the width of the wall. Choosing stones that fit neatly between the bondstones tie the front and rear bondstones at the ends of the wall wythes together. You'll need one of these stones every 4 to 6 feet. Dry-lay the first course of both wythes, choosing stones that fit neatly between the bondstones at the ends of the wall.

Remove 3 to 4 feet of stones at each end of the wall and set them aside in order. Apply a 1 -inch-thick layer of mortar to the exposed section of footing and furrow it lightly. Set the first course in the mortar. Pack the joints between stones with mortar. Allow the mortar to set slightly so it isn't dislodged by subsequent stones. Dry-lay a few stones at each end of the second course to make sure they bridge the joints below. When you're satisfied with the fit, lay the stones in mortar. Fill in between the wythes with smaller stones and mortar. Continue building courses. After each one, check the slope, or batter, of both the wythes and the wall end with the batter gauge and a level. When the mortar is firm enough to hold a thumbprint, run a concave jointer over the joints to remove excess mortar.

Start in the corner, setting two stones at right angles to each other in each wythe. Dry-lay the rest of the stones in the first course. Remove the first 3 or 4 feet of stones, then set them in an inch of mortar. Fill the space between the wythes with rubble and mortar. Test-fit the stones, overlapping them as shown. When you're satisfied with the fit, set the stones in mortar. Continue building up the lead one course at a time, test-fitting, setting them in mortar, and filling the gap between the wythes with stones and mortar. Check the slope, or batter, of each wythe with the batter gauge and a level as you build up the corner lead. When the mortar is firm enough to hold a thumbprint, run a concave jointer over the joints to remove excess mortar.

Put the stones in a 1-inch mortar bed. Drive stakes into the ground at the ends of both wythes and run mason's lines between them at the height of the leads' second course. Dry-lay the second course of both wythes between the leads, choosing stones that sit roughly 1/2 inch below the lines. Put the stones from each wythe aside, keeping track of how they fit together. Apply a 1-inch-thick layer of mortar on the first course of stones, then lay the second course of stones. Once the course has been completed, move up the mason's lines and dry-lay the third course.

Build the wall a course at a time, test-fitting the stones before you set them in mortar. Fill the space between wythes with rubble and mortar. Move the mason's lines up at the start of each course to help you keep the wall level. Check your progress often with the batter gauge and a level. If you make a mistake, remove the stone and scrub it with a wet brush before repositioning it. Dirt, grit, and dried bits of mortar weaken the joint.

As you work, pack mortar into the joints between the stones. Scrape off the excess mortar that squeezes out as the stones are set. When the mortar between the stones is firm enough to take a thumbprint, run over the joints with a concave jointer 1/2 inch deep or so. For the cap, choose the flattest stones you can find. Line up the stones with mason's lines set at the finished height of the wall. Lay a 1-inch-thick bed of mortar and set the stones in place, tapping them with a trowel handle.