Repairing Cobblestone Edging
The cobblestone edging along my gravel driveway keeps getting knocked over by car tires. Anything I can do to prevent that?
—Erin Peebles, Mobile, AL
Roger Cook replies: If a car tire can push your cobblestones out of alignment, then they’re probably just bedded in earth, like the one I’m resetting (shown). To stop the stones from moving, they should be set into a concrete pad.
Start by removing the existing edging. If you’re lucky, the blocks you have are jumbos—roughly 10 by 7 by 4 inches—like the one I’m lifting here. That’s the size you want along a driveway because it can be buried nice and deep. Stake out the path of your edging on the driveway side, and tie a taut string line between stakes to guide your digging. Excavate a flat-bottomed trench roughly 1 foot wide and 10 inches deep.
Next, set the string line 3 inches above the gravel. That’s the height the edging should be to hold back the gravel. Now mix a bag of concrete in a wheelbarrow and pour a 3-inch-thick layer into the trench. Place the first cobblestone narrow end down in the concrete so its top sits about 1½ inches above the string. Then, using a rubber mallet, pound the stone down until it’s level with the string line.
Continue setting cobbles tightly together until you reach the end of the pad, then trowel a wedge of concrete against the back of the stones up to the driveway surface. Repeat until the edging is complete. There’s no need to mortar between the stones; it would just crack and need to be repointed.