914 Basement Waterproofing in Armonk & North Castle, NY
Armonk (Town of North Castle) skews newer than the coastal villages: the typical home was built around 1989, though 43% still pre-date 1980. On large wooded lots, drainage and grading often matter more than the basement wall itself. Homes on hillsides, near brooks and rivers, and along the Long Island Sound shore can see very different water patterns, so the right fix depends on where the water comes from. For a house with finished space or valuable contents, ask each company to show you the source of the water and to explain what happens in a power outage.
Waterproofing companies for Armonk & North Castle
How we pick: we list up to six companies per page. Independent firms come first, then firms based outside Westchester, then franchise or network affiliates. Companies that name the town as served come before those that serve the whole county. Listings are free, not paid, and not an endorsement. Home improvement license status was looked up in the Westchester County consumer license search on Oct 26 to 27, 2026, plumber license status in the county trade license search on Oct 27, 2026, and NYS mold license status in the state Labor Department data set; each profile shows what we found.
De La Paz Masonry
No rating collected yetWaterproofing, French drains, sump pumps, masonry
F. La Rocca & Sons
No rating collected yetMasonry, drainage and waterproofing
Mazzacone Contracting
No rating collected yetInterior and exterior waterproofing, drainage, sump pumps, excavation
Naclerio Construction LLC
No rating collected yetBasement waterproofing, drainage, masonry and foundation work
Sundahl Waterproofing
No rating collected yetInterior and exterior waterproofing, drainage, sump pumps, foundation repair
Gregg Segnit Waterproofing
No rating collected yetBasement and foundation waterproofing, drainage, sump pumps
Housing in Armonk & North Castle
| Place | Typical year built | Built before 1950 | Built before 1980 | Median home value |
|---|---|---|---|---|
| Armonk | 1989 | 13.6% | 43.2% | $1,073,300 |
Source: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates (tables B25035, B25034, B25077), retrieved Oct 2026. Estimates carry a margin of error.
Flooding and water in Armonk & North Castle
- Westchester County’s Long Island Sound watershed program lists this municipality in the watershed study areas for “Silvermine, Mill and Mianus Rivers”, “Byram River”, “Bronx River”. [source]
- The town publishes a floodplain development permit application for work in flood hazard areas. [source]
- Flood maps are address-specific. Check your own address on FEMA’s flood map service, and ask any contractor how they treat a high water table on your lot. [source]
Permit notes for Armonk & North Castle
From the municipality’s own pages, retrieved Oct 2026. Rules change, so call the building department before work starts.
- Excavation and related work need a building permit from the Town of North Castle Building Department, 17 Bedford Road, (914) 273-3000 ext. 44. [source]
- A sump pump that ties into drainage, a floor drain or a sewage ejector may need a plumbing permit. [source]
- Excavation, grading and watercourse work can trigger town stormwater review. [source]
What it costs
A modeled estimate for White Plains puts a typical interior drain system for about 120 linear feet of wall near $7,100, with most bids between roughly $3,000 and $12,200 (RenoVetted). Exterior drainage is modeled at $4,600 to $18,200 and full exterior waterproofing at $5,700 to $22,800 for the same 120 feet. These are modeled figures, not Westchester bid data, and larger or harder-to-access homes can cost more. We did not find any Westchester contractor price lists. Full cost guide with sources.
Frequently asked questions
How many waterproofing companies serve Armonk & North Castle?
We show 6 of 13 companies we found for Armonk & North Castle: 6 name Armonk & North Castle as an area they serve, and the rest serve all of Westchester County. Always confirm a company covers your address.
Does Armonk & North Castle require a permit for this work?
Often yes. See the permit notes on this page, then call the Armonk & North Castle building department before you sign a contract.
Is interior or exterior waterproofing better?
Exterior work stops water at the wall face but means digging out the foundation, which is disruptive and costs more, especially around mature landscaping. Interior drainage systems collect water that gets through and send it to a sump pump. Ask each company to explain why it recommends one approach for your house.
Will a sealer paint fix my wet basement?
Coatings can help with minor dampness, but they rarely stop water under pressure from saturated soil. If you see water at the floor-wall joint or through cracks, get a drainage assessment first.
Nearby
Sources
- Westchester County Planning: Long Island Sound Watershed Program (watershed study areas by municipality)
- Town of North Castle: Floodplain Development Permit Application
- FEMA Flood Map Service Center (look up your own address)
- Town of North Castle: Building Applications & Information
- Town of North Castle: Plumbing Permit Application
- Town of North Castle Code, Chapter 267: Stormwater Management
- U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, tables B25034, B25035, B25077 (via Census Reporter)
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