Commercial Concrete Patios and Landings

Many pedestrian slabs are designed around 125 to 150 mm, but thickness changes with soil, frost, reinforcement, vehicles, planters, stairs, structural support, and edge loads. The project drawings and geotechnical recommendation govern. Harrowgate trims the base accurately so the specified thickness is maintained across the entire panel.

The mix is selected under CSA A23.1 for the applicable freezing, wetting, and deicing exposure, including strength, air entrainment, and water-cementing materials ratio. Site conditions and structural design also apply. Harrowgate verifies delivery and field tests where specified and does not add uncontrolled water to simplify finishing.

Slope must drain water while meeting door, stair, ramp, and accessible-route limits. A common design may use roughly 1 to 2 percent on open slabs, but the project geometry governs. Harrowgate sets survey control at thresholds, drains, and edges and checks the surface during placement to prevent ponding.

Concrete shrinks as it dries and moves with temperature. Contraction joints create planned weakened planes so cracking occurs at deliberate lines. Isolation joints separate the slab from fixed structures, and construction joints define pour limits. Joint spacing, depth, timing, and layout must coordinate with panel shape, reinforcement, and embeds.

A bonded overlay may suit limited sound conditions, but pouring another slab over failed support usually preserves the settlement cause and creates threshold problems. Harrowgate removes the old concrete, evaluates subgrade and drainage, rebuilds compacted base, and places the designed section. Structural overlays require a specific engineered detail.

Access depends on mix strength development, curing, temperature, slab design, and load. Foot traffic can return before planters, lifts, vehicles, or concentrated equipment. Harrowgate defines separate release points and keeps barricades in place. Early loading can crack edges or imprint a surface that appears hard but is still developing strength.

Provide grading and structural plans, dimensions, elevations, slab and base detail, reinforcement, finish, steps or guards, embeds, drainage, testing, access, removals, and restoration limits. A site review confirms utilities, truck or pump access, occupied entrances, weather protection, disposal, and phasing around building operations.