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Long Island Waterproofing | Foundation, Drainage & Basement Waterproofing
Protecting Long Island basements since 1999
(516) 312-3285 longislandwaterproofing2026@gmail.com
Hero photo placeholder: replace with a wide shot of a finished, dry basement
Long Island WaterproofingFoundation & Basement Specialists
Nassau & Suffolk County Waterproofing

A dry basement isn't luck. It's the right system, installed right.

Long Island Waterproofing has been keeping local basements dry since 1999. Foundation waterproofing, drainage systems, crack repair and egress windows, done by a crew that's been doing this since before most companies existed.

Call (516) 312-3285 See Our Work
25+Years on Long Island
100%Free, no pressure estimates
Licensed& insured crews

Get a Free Waterproofing Estimate

Tell us what's going on. We'll call you back to schedule a free visit.

No obligation. We respond within one business day.

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Licensed & Insured
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Serving LI Since 1999
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Free Estimates
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Locally Owned Crew
The difference

See a basement before and after we fix it

Drag the handle to compare the same spot before and after waterproofing.

Basement after waterproofing
Basement before waterproofing
Before After
Services

Everything that keeps water out, in one place

We don't patch symptoms. Every job starts with figuring out where the water is actually getting in, then we fix that.

01

Foundation Waterproofing

Exterior and interior systems that stop water at the source instead of masking it with paint or patch jobs.

02

Drainage Systems

Interior and exterior drainage designed to move water away from your foundation before it becomes your problem.

03

Egress Windows

Code compliant egress windows installed cleanly, adding light, ventilation and a safe exit point to any basement.

04

Interior Wall Repair & Sealing

Basement wall repair and sealing that addresses seepage, cracking and moisture damage from the inside out.

05

Exterior Drywells

Drywell installation to capture and disperse runoff and downspout water before it pools against your foundation.

06

Foundation Crack Repair

Structural crack repair that seals the entry point and stops the same crack from leaking again next season.

How It Works

From first call to a dry basement

A straightforward process, the same one we've used for over 25 years.

1

Free Inspection

We walk the property, inside and out, to find where water is actually entering.

2

Straight Estimate

You get a clear, written estimate for the actual fix, no inflated scope.

3

Clean Installation

Our crew handles the job start to finish and protects your property while we work.

4

Dry, Guaranteed

We walk the finished work with you before we consider the job done.

Excavation and drainage work on a Long Island property
Why Long Island Homeowners Call Us

Work that's been holding up since 1999

  • 1

    Local, not a franchise

    We've worked on Long Island soil, Long Island foundations and Long Island weather for over two decades. That's the whole business.

  • 2

    We diagnose before we dig

    Every estimate starts with finding the actual water path, so you're not paying to fix the wrong thing.

  • 3

    One crew, start to finish

    The people who quote the job are the people who show up and do it. No subcontractor handoffs.

  • 4

    Straight answers, free estimates

    No pressure, no upsell script. Just what your foundation needs and what it costs.

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Years in Business
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Free Estimates, Always
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Core Services Offered
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Counties Served
Service Area

Proudly serving all of Long Island

From Nassau County through Suffolk County, we've worked basements and foundations across the Island for over 25 years.

  • Nassau County
  • Suffolk County
  • North Shore
  • South Shore
  • The Hamptons
  • Nassau & Suffolk suburbs
Foundation and construction crew at work
Reviews

What Long Island homeowners are saying

★★★★★

Our basement flooded every spring for years. They installed an interior drainage system and it's been bone dry since. Wish we called them sooner.

Maria T.
Babylon, NY
★★★★★

Fast, honest quote and the crew actually showed up when they said they would. Fixed a foundation crack that two other companies tried to talk us out of.

Robert D.
Huntington, NY
★★★★★

They added an egress window and exterior drywell in one visit. Clean work, cleaned up after themselves, no surprises on the bill.

Jennifer K.
Smithtown, NY
FAQ

Common questions before you call

Is the estimate really free?+

Yes. Every inspection and estimate is free with no obligation to move forward.

How long has this company been in business?+

Long Island Waterproofing has been serving Nassau and Suffolk homeowners since 1999.

Do you work on both interior and exterior systems?+

Yes. We install and repair interior and exterior drainage, foundation waterproofing, drywells and more.

How fast can someone come out?+

Call us at (516) 312-3285 and we'll get you on the schedule, usually within a few days.

Get a straight answer on your basement, free

Tell us what's happening and we'll tell you what it takes to fix it. No pressure, no obligation.

Call (516) 312-3285 Request Estimate Online
Contact

Let's take a look at your basement

Call, email, or send the details below and we'll get back to you to schedule a free, no obligation estimate.

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Office

4820 Sunrise Highway, Suite 12, Bay Shore, NY 11706

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Hours

Monday to Saturday, 7:00 AM to 6:00 PM

Request a Free Estimate

Fill this out and we'll follow up to schedule a visit.

We respond within one business day.

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