The old concrete is broken up with a rented jackhammer and hauled away to the dump. (Note to Kelvin: It's a good idea to don a dust mask and hearing protection when using a jackhammer or stone-cutting saw.) The site was dug down to a depth of 25 centimetres (10 inches) and topped up with 15 centimetres (six inches) of limestone screenings (to calculate how deep you need to dig, factor in the thickness of your paving material, too). Slowly add fill with a shovel, smoothing and levelling it with a screed, a straight piece of wood. (Although we didn't have to worry too much about factoring in the grade away from the house because there's a natural slope, you might need to-about six millimetres [1/4 inch] per running foot works fine.) Tamp down well-for larger projects, Steve Maxwell suggests a minimum of three passes with a gas-powered tamper. Next, lay landscape cloth (to subdue weeds) on top of the screenings (don't substitute black plastic, which doesn't drain), followed by five centimetres (two inches) of clean, sharp sand, also tamped down well. Check level and slope.
 The first course of sandstone slabs is laid, butted against and flush with the city sidewalk. The stones were rough-fitted and trimmed as needed. Be sure to leave a six millimetre (1/4 inch) space between slabs for sand. (Kelvin recommends using polymeric sand, which, though tricky to apply, is worth the effort.)
 The risers for the first step are put into position, tapped in place with a rubber mallet, then checked for levelness.
 The hollows in the blocks are filled with gravel; an additional 15 centimetres (six inches) behind the blocks is backfilled with gravel for stability and drainage. An area for the first stair tread (the width of one slab) is built up with screenings and sand and compacted well, then checked for levelness and slope. A second riser and the path to the porch are prepared the same way.
 Working from the porch down, stone slabs are dry-fitted. Those resting on the risers are secured with a thin bead of Sonneborn Premium Adhesive, applied with a caulking gun (it bonds permanently, so wear gloves).
 After ensuring slabs are level, spaces between stones are cleaned out a bit to make more room for the polymeric sand.
 Polymeric sand is worked deep into spaces between slabs using a stiff brush.
Andrew's Restoration Ltd., 1138 15th Sdrd., Oak Ridges, ON L7B 1K5; 905/773-9771.
Beaver Valley Stone Ltd., 25 Langstaff Rd. E., Thornhill, ON L3T 3P7; 416/222-2424: Allan Block Junior, $2.87/piece; Indiana split-face limestone, $24.19/linear foot.
Advanced Building Materials, 770 Chester St., Sarnia, ON N7S 5N1; 800/216-9923: Sonneborn Premium Adhesive, 300mL $4.95; 825mL $12.25.
Aqua Supply Inc., 3828 15A St. SE, Calgary, AB T2G 3N8; 403/262-3929: 825mL $8.65.
The Brickyard of Canada Inc., 4570 Sann Rd., Unit 2, Beamsville, ON L0R 1B1; 905/563-8660: Sonneborn Premium Adhesive, 300mL, $6.98.
Entreprises Givesco, 9495 Pascal Gagnon, St-Léonard, QC H1P 1Z4; 514/327-7175: Sonneborn Premium Adhesive, 300mL, $4.95; 825mL, $12.25.