In this video, This Old House landscape contractor Roger Cook helps a homeowner repair a cracked stone walkway.
1. Pry up the walkway stones with a flat bar.
2. Use a shovel to scrape all the existing sand from beneath the stones.
3. Mix stone dust and water in a wheelbarrow to create a mortar setting bed.
4. Shovel some stone-dust mortar onto the concrete base.
5. Smooth the mortar with a pointed trowel.
6. Set the new stone into place; add more mortar if the stone is too low.
7. Using a rubber mallet, gently tap down the stone.
8. Shovel more mortar onto the concrete base right beside the first stone.
9. Tap down the second stone until it's flush with the first stone.
10. If necessary, cut a stone slab to fit using either an angle grinder or circular saw fitted with a diamond-impregnated masonry blade.
11. Set the remaining stones in a bed of stone-dust mortar.
12. Clean the walkway surface of all wet mortar.
13. Scrape the fresh mortar out from between the stone slabs with a steel stake or slotted screwdriver.
14. Use a push broom to sweep polymeric sand across the surface, filling the joints between all the stone slabs.
15. Sweep the surface clean of excess sand, then use a garden hose to mist the entire surface with water.
16. Wait 15 minutes and spray the walkway again.
17. If there isn't a concrete base under the walkway, remove the stones, dig out the topsoil, and then fill the area with stone dust.
18. Compact the stone-dust base, then set 1½-inch-thick stone slabs.