Basement waterproofing in Sydney

Sydney’s basements are shaped by a combination nowhere else in Nova Scotia has: a coalfield under the city and housing built for the people who worked it.

The geology is the first difference. Sydney sits on Carboniferous sandstone, shale and coal measures, not the granite and slate that define the Halifax area. Sandstone transmits water rather than shedding it, so groundwater arrives at a foundation wall as a steady supply rather than a slug that passes a day after the storm. That changes the fix. A wall that weeps for a week after rain is not telling you the same thing as a wall that runs for six hours and dries.

The housing is the second. A great deal of Sydney was built between 1900 and 1950, much of it company housing on small lots: modest footprints, shallow cellars, and foundations that were never waterproofed because nobody waterproofed foundations then. The oldest stock is stone and rubble, which weeps through mortar joints along its whole length rather than cracking in one place. Post-war infill is block and early poured concrete, where the leaks are at cold joints, form-tie holes and the slab–wall joint.

Whitney Pier, Ashby and the flats around the former Muggah Creek estuary are low, close to the harbour, and built on fill that drains slowly. Water tables there sit high enough that hydrostatic pressure under the slab is the primary problem, and interior perimeter drainage with a properly sized sump is usually the honest answer rather than more sealant on the wall.

Then there is what everyone here already knows. The Thanksgiving flood of October 2016 dropped over 200 millimetres of rain on the Sydney area in about a day and put water into hundreds of basements across the CBRM. It was not a fluke of one bad storm; it was a demonstration of what happens when century-old drainage meets the kind of rain event that is arriving more often. Homes that took water then are, in our experience, the homes that will take water again unless something structural about the drainage changes.

Snow is the quiet factor. Sydney records some of the heaviest seasonal snowfall in the province, and snow banked against a foundation all winter does not run off in spring. It melts directly into the soil at the wall, at exactly the point where you least want a concentrated water source.

Cape Breton is a standing part of our schedule, not an occasional trip. We assess in Sydney and across the CBRM on regular routing, and the assessment is free whether you are in Whitney Pier or out the Mira Road.