What do you need done?
Basement waterproofing
Interior drainage systems, sump pumps, wall vapor barriers and the outside fixes that stop water before it reaches the wall.
Interior vs. exterior systems →Sump pumps & backups
New pits and pumps, replacements, battery and water-powered backups, check valves and discharge lines that do not freeze.
Pump sizing & backups →Foundation crack repair
Epoxy and polyurethane injection for poured walls, block wall sealing and bowing-wall reinforcement with carbon fiber or anchors.
Which cracks matter →Crawl space encapsulation
Vapor barriers, drainage, sealed vents and dehumidification for the dirt crawl spaces under Rockland's older houses and additions.
What encapsulation involves →Why Rockland basements get wet
Rockland was built out between 1950 and 1980 on ground that was never meant to hold dry basements: the Pascack Brook valley through Nanuet, Spring Valley and Pearl River; the Hackensack headwaters, lakes and wetlands around Congers and West Nyack; the Mahwah and Ramapo rivers at Suffern; the Sparkill Creek through Orangetown; clay soil across the flat towns and hillside groundwater along the Ramapo slopes and in Stony Point. Block foundations with finished basements take that water through the cove joint and through the block itself, and the original sump pits, where they exist, were never connected to a drain.
The fix is well understood: stop surface water outside (downspouts, grading, window wells), collect groundwater inside with a perimeter drain under the slab edge, pump it out through a properly sized sump with a backup, and keep the walls and air dry with a vapor barrier and dehumidifier. Poured-wall cracks are injected; crawl spaces are encapsulated; walls that have bowed are reinforced. The contractors we match you with hold the Rockland County home improvement license that county law requires, carry insurance, and quote in writing after looking inside and out.
Waterproofing costs in Rockland County (2026)
| Job | Typical price | What drives it |
|---|---|---|
| Foundation crack injection (epoxy or polyurethane) | $250 – $800 per crack | Crack length, poured vs. block wall |
| Sump pump installation (pit, pump, discharge) | $1,000 – $3,000 | Cutting the slab, discharge routing |
| Battery backup sump pump | $400 – $1,500 installed | Pump size, battery type |
| Interior perimeter drain + sump (full basement) | $5,000 – $15,000 | Linear feet, slab thickness, finished walls to remove |
| Exterior excavation waterproofing | $10,000 – $30,000+ | Depth, access, landscaping and walks to restore |
| Crawl space encapsulation | $3,000 – $15,000 | Size, drainage, dehumidifier |
| Grading, downspout extensions, window well covers | $300 – $3,000 | Often the first and cheapest fix |
| Basement waterproofing, typical project | $2,300 – $7,600 (avg. about $5,000) | Angi / HomeGuide 2026 figures |
Ranges are published 2026 national figures (Angi's and HomeGuide's basement waterproofing cost guides for typical projects, interior French drain and exterior excavation ranges; HomeGuide and Angi sump pump and foundation crack repair pages; crawl space encapsulation figures from HomeGuide), not quotes from this site. Rockland quotes for interior drainage systems typically run in the upper half of national ranges. Details: Rockland waterproofing cost guide.
Towns we serve
New City
Clarkstown colonials with finished basements; spring groundwater along the Demarest Kill and Hackensack headwaters.
Local notes & quote →Nanuet
Pascack Brook flood zone (Ida 2021), low capes and splits, high water table.
Local notes & quote →Spring Valley
Dense village housing, basement apartments and the Pascack Brook's upper reaches.
Local notes & quote →Monsey
Expanded homes, basement bedrooms and playrooms, and additions over the original footings.
Local notes & quote →Nyack
Stone and rubble foundations, hillside groundwater, old cellars and crawl spaces.
Local notes & quote →Suffern
Mahwah and Ramapo river flooding, hillside seepage along uphill walls, and village cellars.
Local notes & quote →Pearl River
1920s–60s houses with original basements and crawl spaces, Pascack Brook flooding, Orangetown clay.
Local notes & quote →Haverstraw
19th-century brick and stone foundations, basement apartments, the Minisceongo Creek and the river.
Local notes & quote →Also Stony Point, Congers, West Nyack, Orangeburg, and every other Rockland County community: Valley Cottage, Bardonia, Tappan, Blauvelt, Piermont, Sparkill, Upper Nyack, South Nyack, Chestnut Ridge, Airmont, Hillcrest, Sloatsburg, West Haverstraw, Garnerville, Thiells, Pomona, Wesley Hills, New Hempstead and Montebello. See all service areas.
Before you sign anything
Waterproofing has more high-pressure selling than any other home trade: the same-day discount, the scary moisture meter, the system that costs three times the next quote. Get two quotes for anything over a few thousand dollars (the second is free here), make sure each names linear feet, pump model, backup and discharge, and be suspicious of any contractor who does not walk the outside of the house first. In a surprising number of Rockland basements, extended downspouts and six feet of regrading are the whole fix.
How it works
- Tell us about the job. Where and when the water shows up, whether the basement is finished, and whether there is a sump already. Photos help.
- We match you with a local pro. One independent waterproofing contractor, licensed in Rockland County and insured, that serves your town. We do not send your request to five companies.
- Get a free quote. They inspect inside and outside and quote in writing, with linear feet, pump, backup and warranty named. You decide; no fee and no obligation.
Waterproofing questions from Rockland homeowners
How much does basement waterproofing cost in Rockland County?
Angi's and HomeGuide's 2026 typical-project range is $2,300 to $7,600, average about $5,000; a full interior perimeter drain and sump system runs $5,000 to $15,000, exterior excavation $10,000 to $30,000 or more, crack injection $250 to $800 per crack, and a sump pump install $1,000 to $3,000. Rockland interior systems usually sit in the upper half of national ranges.
Interior or exterior waterproofing?
For an existing Rockland house with seepage, an interior perimeter drain with a sump and backup handles groundwater at a fraction of the cost and disruption of digging. Exterior is for failing walls, new construction, or one accessible wall that is the whole problem.
Is this site a waterproofing company?
No. We are a free referral service for Rockland County homeowners. You tell us what the basement does; we pass it to an independent, licensed and insured local waterproofing contractor who serves your town, and they quote you directly. We never charge you anything.
Do I need a permit?
Cutting the slab for a drain and sump, and excavating against the foundation, are commonly permitted in Rockland towns and villages; grading, downspouts and crack injection usually are not. The contractor applies.
Will insurance pay for waterproofing?
No. Homeowners policies exclude groundwater seepage and do not cover prevention. Sewer backup needs its own endorsement; flooding needs flood insurance. Waterproofing is a maintenance investment, usually recovered at sale.
What license should the contractor have?
The Rockland County home improvement contractor license (Chapter 286 of the county code), which requires insurance. Ask for the license number and a certificate of insurance naming you before work starts.
Request a free quote
Prefer to talk? Call (845) 999-0485, leave a message and we'll call you back.