Case Study: Interlock Patio Upgrade in Plateau

When the owners of a classic Plateau duplex contacted us, their backyard patio was in rough shape. The original poured concrete slab, likely installed in the 1980s, had cracked extensively due to decades of Montreal freeze-thaw cycles. Water pooled in the center after every rainfall, and the uneven surface had become a tripping hazard. The homeowners wanted a durable, modern outdoor space where they could host dinners and relax during the short but cherished Montreal summer season. The Plateau presents unique challenges for landscaping projects. Lots are typically narrow with limited rear access, which means careful logistics for material delivery and equipment maneuvering. We planned the demolition and material staging to minimize disruption to the laneway and neighboring properties. After removing the old concrete slab and excavating to a depth of 14 inches, we discovered that the original installation had no proper base whatsoever -- the concrete had been poured directly over clay soil, which explained the severe cracking and settling. We installed a geotextile membrane followed by compacted 0-3/4 inch crushed limestone in four-inch lifts, building a stable 10-inch granular base. For the surface, the clients selected Techo-Bloc Blu 60mm pavers in Champlain Grey, laid in a herringbone pattern that provides excellent interlock strength. We corrected the drainage by grading the base with a two-percent slope toward the rear of the property, and added a linear channel drain along the fence line connected to an existing catch basin. Polymeric sand was applied to all joints to lock the pavers in place and prevent weed growth. The project was completed in six working days, transforming a crumbling concrete slab into a clean, level, and beautifully finished patio that can handle everything Montreal weather throws at it. The homeowners were thrilled with the result and reported that the drainage issues were completely resolved after the first heavy rainstorm following completion.