Keystone Foundation & Waterproofing

Nineteen Google reviews average 4.8 for this Cambridge outfit, and what stands out is how specific the write-ups get: a full foundation excavation with a new drainage system, decades-old fieldstone walls that finally stopped leaking, a flooded basement dried out on schedule. Keystone Foundation & Waterproofing takes on that kind of foundation and basement work across the greater Boston area. The specifics repeat across more than a dozen reviews filed since February. One customer said a full excavation paired with a new drainage system and sump pump was 'handled flawlessly' with steady communication start to finish. Another described cracked exterior walls closed up with hydraulic cement and a full waterproofing membrane, done 'to a high standard' with 'no shortcuts.' A Boston-area customer whose basement flooded every time it rained said the crew came out quickly, gave a fair estimate, finished on schedule, and left the property clean. The one sour note, filed this past April, describes a no-show and calls the crew unreliable and disorganized — worth weighing against the sixteen five-star reviews filed in the same stretch, but real enough not to wave away. Nothing else in the reviews points to a recurring problem with scheduling or the work itself. For a cracked, bowing, or chronically wet foundation — especially in the older fieldstone housing common around Cambridge — Keystone's recent track record makes it worth a call; just get a firm appointment window in writing given that one no-show report.