Verified record
Key Waterproofing Construction fixes wet basements across Eastern Massachusetts, and the names customers keep writing are Wendel and Stephen. Angi and HomeAdvisor each show 4.7 stars from 198 ratings. Customers with a failed sump pump describe a fast response. In a February 2026 Angi review, a customer whose sump pump broke said the crew was there within an hour for a $1,400 job, and a March 2026 Google reviewer said Wendel came right out and replaced two sump pumps and battery backups. In a July 2025 review, a customer who had used other waterproofers said Stephen moved the sump pump to reclaim basement space and explained how the whole system works, and an August 2024 reviewer described a French drain with two sump pumps, finished on time with the basement cleaned each day. An October 2025 customer said the crew dug about five feet down and cut the foundation for an egress window, laying crushed stone for drainage. In a March 2024 Google review, a customer who booked a sump pump through Angi said the crew let themselves in, left a hole in the wall and broken tile, covered the house in concrete dust, and later came by and confronted the customer's elderly mother about the review. A November 2022 reviewer said new basement pillars were not installed as agreed, the slab cracked, and months later the crew had not come back to evaluate it. Its website lists basement waterproofing, crawl space encapsulation, foundation drainage and sump pump work, and offers free estimates. Its BBB grade is A+.
Really impressed with the work from Key Waterproofing Construction. The team arrived on time and handled everything in a very professional way. They paid attention to the small details and kept the work area organized. The finished work looks great and gave me confidence in the quality. I would happily recommend them to anyone looking for reliable waterproofing work.
The job was completed well and the crew worked hard. They are experienced craftsmen and communicated effectively with the owner and tenant. The job was done quickly after the agreement was made. The crew was on the job the next day! Workers were friendly and answered our questions.
Wendel came right out and replaced two sump pumps and battery backups for us. Communication was clear and professional and he seems knowledgeable. Very happy with my experience!
Sump Pump or Interior Foundation Drains Installation — $1,400. Our sump pump broke down and they were here within an hour! Highly highly recommended! [Response from Key Waterproofing Construction: "Thanks Andy, even though you had another company?s system, it was important for Key Waterproofing to respond to the call when you needed it."]
Professionals. . Hardworking crew. Clean area and was able to explain the process. (Inspection Service)
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Service area
1 change recorded — last scanned Oct 9, 2026.
Typical Greater Boston range for this kind of work, from regional averages — not a quote from KEY WATERPROOFING CONSTRUCTION. Use it to sanity-check bids, then get the real number in writing.
Not sure which you need? Start with an inspection — many reputable companies assess free, and independent assessments run up to $500.
The wall run getting the drain — a full 30×40 ft basement is about 140 ft.
Estimated range
$7,600 – $15,000
Typical waterproofing project around $11,300
Languages
Languages
Basement waterproofing5.0
Retaining walls5.0
Bulkhead replacement4.8
Brick and 1850s fieldstone foundations repointed4.8
Owner-led communication4.8
