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Application of Mapei's Fibre Reinforced Cementitious Matrix (FRCM) system. M A R C H 2 0 2 4 | 57 Restoration Products & Services P H OTO G R A P H Y CO U RT E S Y M A P EI ; R J C EN G I N EER S Growing demand for restoration projects stirs up heightened interest in associated products and services by ROBIN BRUNET A t a time when many projects across Canada are being can- celled or put on hold due to high interest rates, restoration projects continue to prolifer- ate, for a simple reason. "A lot of restoration is vital, consider- ing building or infrastructure operations are often at stake," says Jeremy Horst, principal, building sci- ence and restoration at RJC Engineers (RJC). RJC's specialized structural restoration teams deliver the company's collective structural engineer- ing, building science, materials science, and prime consulting expertise. The combined skills have led to the successful restorations of a huge variety of facili- ties, ranging from unique (the 257-year-old Sambro Island Lighthouse in Halifax), heritage (the mas- sive redevelopment of the mid-century Canada Post Vancouver headquarters, now known as The Post, and nearing completion) to institutional. Horst notes that "in the past five or so years we've seen a revision of repair methodology for below- grade work: Instead of excavation from the exterior and applying bitumen-based products to stop build- ing foundation leakages, we're increasingly being called upon to perform injection drilling on grid pattern spacing from the inside of the structure." Specifically, to achieve an elastic sealing of cracks or joints in the structure, the broader area is sealed over its entire course with an acrylic gel waterproof- ing resin via pressure injection. This is known as the area injection method. "We use Koster products that we pump through half-inch diameter holes that are drilled straight through to the structure's exterior, and the system is so effective it comes with a 10-year warranty," Horst says. Currently, RJC is using the system to seal 3.2 kilo- metres of service tunnels at a Toronto university, and it was recently tasked with waterproofing stone rubble foundations of a historic Toronto building. But the solution isn't cheap: over $10 million is being spent on the university project; Horst points out that "the system is ideal for situations where exterior excavation isn't feasible – such as leaky elevator pits. And its effectiveness is increasingly being rec- ognized in the restoration sector, so we anticipate many more projects of this kind in 2024." Brothers Jonathan, Matthew, and Mark Atwill-Morin are the third generation along with Nicolas Croteau to run Atwill Morin & Associates, whose rehabilitation of the McGill University Strathcona Music Pavilion project recently won the International Concrete Repair Institute's Award of Merit in the masonry category. For this project, Atwill-Morin was the first Canadian contractor trusted by Mapei and engineers to use Mapei's new Fibre Reinforced Cementitious Matrix (FRCM) system designed for masonry. The Strathcona project required damaged bricks to be replaced or repointed, with stainless steel bars inserted for local reinforcement. The FRCM system was used to smooth wall surfaces in specified areas, and layers of structural mesh were added to wrap and strengthen the walls held in place by the mortar. Additionally, carbon fibre cords inserted into drilled holes spread out in a star formation and covered with epoxy were used as a strengthening solution. Matthew Morin reports that even though the volume of new construction declined in 2023, "We had a 22 percent growth – which is further evidence that restoration projects continue to be a priority for many clients." Revive & Thrive Service tunnel waterproofing via the area injection method. Rehabilitation of the McGill University Strathcona Music Pavilion.

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