How to Build a Stone Wall, Part One
A freestanding mortared fieldstone wall blends strength with the natural look of a dry stack
By ROGER COOK, THIS OLD HOUSE MAGAZINE
Stone walls are a handsome way to define and improve your property. Building them is backbreaking work, but if done correctly, the wall will last a lifetime, if not a lot longer. I like to set stones in mortar because you can’t beat a mortared wall for strength, which is important if a wall serves as seating or holds back earth. To preserve a dry-laid look, I set the stones in a mortar that’s pigmented a dark gray and then rake the joints clean. Freestanding mortared walls, like the fieldstone one I’m building here, need a stable, frost-proof footing to prevent shifting, and that requires a lot of digging in cold climates. Ask a stone yard to help determine how much material you’ll need, and have it delivered as close to the site as possible. Once built, you’ll have a rock-solid wall without all the heavy mortar lines.
Step 1: Prepare The Footing
Dig a trench that’s below the frost line and 2 feet wider than the wall. Line it with landscape fabric overlapped 12 inches at the seams, add a 6-inch layer of ¾-inch stone, and tamp it with a plate compactor. Add and tamp more layers until the footing is about 8 inches below grade. About a foot beyond each end of a straight wall section, drive two stakes, separated by a distance equal to the width of the wall.
Step 2: Lay The Base Course
Connect the stakes with a mason’s line set just above grade. Place the first stone at a corner with its face grazing the line. Position the next stone against the first, face to the line, and so on until the first course is laid. Repeat on the opposite side. Fill between the two rows with smaller stones, set flush with the tops of the face stones. Top this course with a bed of mortar.
Step 3: Build Up The Wall
Reposition the line higher up the stakes and start the second course from a corner. Dry-fit each stone first to see that the vertical joints are staggered and the outside faces just touch the line. Remove the stone, spread a trowelful of mortar on the wall, and tamp the stone into it with a mallet. The face stones’ visible edges should rest only on stone, not mortar, so scrape away any mortar that squeezes out.
This is a fairly dense post so we have elected to present it in two parts. Thanks again to This Old House and stay tuned for Part Two.