Keystone Masonry and Chimney,Foundtaion Waterproofing

Keystone Masonry and Chimney is a Waltham shop built around three connected trades — foundation waterproofing, chimney rebuilds, and general masonry — with James doing much of the hands-on work the reviews describe. Across two Google listings the company holds 4.9★ from 62 ratings and 4.8★ from 19, and the written record behind those numbers runs from 2022 through mid-2026. The recurring story is dry basements and rebuilt chimneys: reviewers describe foundation cracks patched with hydraulic cement and a full waterproofing membrane, drainage systems and sump pumps installed after years of standing water, and chimneys that had sat unused for decades brought back into service with new crowns, caps, and flashing. A few reviews describe free follow-up work — in a 2023 review, a homeowner had a missed section of a brick-foundation job finished at no charge, and in a December 2025 review, another had a loose roof fixture secured for free. A few things are worth confirming before booking. The company's Massachusetts home improvement contractor registration (209863) is now listed as expired in the state registry. A review from April 2026 reports a no-show and disorganized scheduling, without further detail. And in a 2022 review, a customer described a chimney-and-patio job that went badly — a broken skylight, an unfinished patio, and no itemized quote before billing started. Separately, a handful of the five-star reviews repeat identical or near-identical wording: one review about a full foundation excavation and waterproofing job is posted twice, word for word, on the same day in March 2026, and a review about a historic home with a failing chimney appears twice — once in November 2025 and again in February 2026 — with only the town changed between postings. For a chimney rebuild, foundation crack repair, or basement waterproofing job, the detailed praise on file spans many different addresses and years — just confirm the current registration status and get a written, itemized quote before work begins.