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Basement Water Solutions

The Best Crawl Space Waterproofing in Long Island

Suffolk & Nassau County Crawl Space Experts

If you have water in your crawl space, it can create all types of problems – mold, rot, and structural damage. But ACM can help. We install reliable crawl space waterproofing systems in Long Island that keep your crawl space safe and dry.

We have waterproofed crawl spaces throughout Long Island for decades, helping thousands of homeowners protect their homes. So call us today to schedule your free crawl space waterproofing inspection and quote.

Protect Your Home Today

We make it simple, affordable, and stress-free — with guaranteed results.

What Is Crawl Space Waterproofing??

Crawl space waterproofing is the process of keeping water out of the space beneath your home — and away from your foundation. On Long Island, where high groundwater and heavy storms are common, waterproofing is an essential step to protect your crawl space from moisture damage.

At ACM, we install perimeter French drain systems designed to collect and channel water toward a crawl space sump pump, which actively moves water away from your home through a discharge line. This combination prevents standing water, stops moisture from seeping into your floor system, and helps keep your entire home dry and stable. For added peace of mind, we also offer battery backup pumps to ensure your system keeps working during power outages.

How Did Water Get Into Your Crawl Space?

Water can get into your crawl space in a few different ways. Melted snow in the spring or heavy rains can lead to water pooling in your yard and trickling into the crawl space. Damaged gutters or missing downspouts will allow water to fall next to your foundation and into your crawl space.

If the soil around your home is waterlogged from heavy storms or you live near the shoreline, water can even seep up through the ground into your crawl space through the dirt floor or even through concrete.

Why Crawl Spaces Flood on Long Island

Long Island’s geography presents unique challenges for crawl spaces. Many homes are built in low-lying areas with high water tables, especially near the coast or in older neighborhoods. During heavy rains or rapid snowmelt, water can pool around the foundation and seep into your crawl space.

Clay-heavy or poorly draining soil makes the problem worse, as water has nowhere to go. Without a reliable waterproofing system, this moisture builds up over time, leading to mold, rot, and structural damage. That’s why Long Island homeowners trust local waterproofing specialists like ACM — we understand the terrain and design systems that actually work in our environment.

Why Crawl Space Water is Such a Problem

Mold Growth

Mold grows in dark, damp, humid places, and mold will grow if you have a wet crawl space. As mold grows, it releases spores into the air. The spores will travel up into the rest of your home, and if inhaled by you and your family, the spores can irritate and even cause allergies.

Rot & Structural Damage

As water enters your crawl space, the wood will absorb the moisture. With high enough moisture, wood will begin to rot. The rotting wood is the support beams and wood joists of your home! A wet crawl space can lead to significant structural damage.

Lower Home Value

A wet crawl space with mold and rot damage can ruin your home’s value. No one wants to buy a home with mold and rot.

We Protect Your Home With Reliable Crawl Space Waterproofing

Crawl space waterproofing can keep mold and rot out of your crawl space, protecting your Long Island home and your family’s health.

Clean the Crawl Space

First, the crawl space needs to be cleaned and any existing water removed. If there is mold, a mold remediation company can remove it. After that, the crawl space is ready to be waterproofed.

Perimeter French Drains

We dig a trench along the perimeter of the crawl space, graded down to a sump pit. Then, we place french drain in the trench, and cover the french drain with stone. Once installed, the french drain captures any water entering the crawl space.

Crawl Space Sump Pumps

In the sump pit, we add a sump pump that collects all of the water captured by the french drain and pumps the water up and out of the crawl space. We also recommend a battery backup sump pump, ensuring the space stays dry even during a power outage when the main pump is offline.

Exterior Drainage

The water pumped out of your crawl space must be safely dispelled away from your home. We add an underground discharge line so the water is expelled at least 15 feet from your foundation.

The completed system works day and night to keep water and all the problems it brings out of your crawl space

How Crawl Space Waterproofing Protects Your Whole Home

Waterproofing your crawl space isn’t just about what’s under your feet — it protects the entire structure and health of your home. When moisture is left unchecked, it can weaken your foundation, compromise air quality, and increase energy costs.

A dry, properly drained crawl space helps:

Maintain your home’s structural integrity
Improve indoor air quality by stopping mold and mildew at the source
Lower energy bills by reducing humidity and making insulation more effective
Prevent costly repairs down the road

Long Island weather isn’t always predictable — but your crawl space can be. Let ACM help you protect your home from the ground up.

Let Us Protect Your Crawl Space

There is no upside to waiting to waterproof your crawl space, only downsides. Taking care of crawl space water now can save you from expensive repairs later. You need a crawl space waterproofer in Long Island you can trust. So give us a call today to schedule your free inspection and waterproofing quote.

Protect Your Home Today

We make it simple, affordable, and stress-free — with guaranteed results.