by Naomi G. in : News and Events
Moore & Sons is currently undertaking a specialized foundation underpinning project designed to increase the ceiling height of a residential property. The homeowners requested an upgrade from the original 7-foot ceiling to a more modern 9-foot clearance. Given the structural constraints, the only viable solution was to lower the existing ground-level floor by excavating downward — a complex and labor-intensive approach requiring expert precision.
This type of underpinning is achieved through a method known in the industry as checkerboard underpinning. To begin, the existing flooring was carefully removed, and an excavation envelope approximately two feet deep was manually dug — due to limited site access that prevents the use of mechanical equipment. In total, our team has removed roughly 20 tonnes of soil entirely by hand.
The underpinning sequence involves constructing and pouring reinforced concrete footing sections beneath alternating segments of the existing foundation walls. Each segment is excavated, formed, reinforced, and poured individually, allowing the structure to remain stable and supported at all times. After sufficient curing of the new concrete (to structural engineer specifications), the process is repeated for the adjacent segment, gradually transferring the load of the structure onto the new, deeper foundation.
This meticulous, phased approach ensures the structural integrity of the home is never compromised during the excavation and re-foundation process. Limited working space and access constraints further add to the challenge, requiring our skilled crew to rely on traditional methods and precision craftsmanship throughout.
Despite the demanding nature of the work, Moore & Sons remains committed to delivering high-quality, code-compliant results on schedule — with minimal disruption to the existing structure.
