Posted on Google Linda WeissTrustindex verifies that the original source of the review is Google. We feel very fortunate to have found this company. I met with Mike regarding leaks in the basement. He assessed the entire house, gave me options and clearly explained the process. Everyone from Mike, to the secretary in the office to the workers were absolutely amazing. They did the work as promised, gave us a reasonable price, and left the place immaculate. We could not be happier with the results! This is a great family owned business. You can’t go wrong!Posted on Google rose smithTrustindex verifies that the original source of the review is Google. The work was done with the utmost professionalism and competence. The service representative was very thorough in examining the dehumidifier, air purifier and sump pump and provided any service needed including draining the pump.Posted on Google Craig TodaroTrustindex verifies that the original source of the review is Google. Mark took it upon himself to come to my home and examine my issue himself. He is knowledgeable not only in basement waterproofing, but also in land grading, excavating and several other adjacent topics. While it was concluded my issue was not foundation oriented, he did not hesitate to propose several other creative ideas to help address my issue. He has a great disposition, and I would not hesitate to recommend his services to others.Posted on Google Linda RussoTrustindex verifies that the original source of the review is Google. I bought my house 24 years ago, and for 24 years I lived with water coming in to my finished basement. A few years back I hired another company to put in a French Drain System which never worked. As the storms got worse the water in my basement increased. Because of my previous experience I was hesitant to hire another company until I read about ACM and met Mark who was highly recommended by my Home Service Company. Mark spent about 2 hours explaining the process, and what was needed. In February 2025 ACM put a extensive French Drain System which included taking down the sheet rock walls, demoing tile and placing a membrane along the whole perimeter of the drain system. All of this work was completed in 3 days exactly what Mark said. The guys were professional, polite, and best of all they were careful to save my Radiant Heating System which was under the tile. Since the French Drain System was placed I have not had 1 drop of water coming into my basement. I am very grateful to Mark's ACM Company, and was able to refinish my basement without fear of water damage. I highly recommend ACM Basement Water Proofing to all who are having water problems with their basement.Posted on Google Maria LacosteTrustindex verifies that the original source of the review is Google. ACM Basement Waterproofing did an excellent job in my basement, no more water intrusion. The job was handled professionally and on time. I am happy to recommend them.Posted on Google William RothsteinTrustindex verifies that the original source of the review is Google. I chose ACM because of their "Best of Long Island" award, and I'm glad I did. Mark's crew (led by Joe) installed an interior French drain and a sump pump in our basement. Six months later, we've had no problems with water. These guys know what they're doing.Posted on Google Links2282Trustindex verifies that the original source of the review is Google. My wife and I would like to say thank you to Mark and his team for their excellent work installing a French Drain in our finished basement. For years we had to worry about flooding if we got a large amount of rain in a short time. The entire staff was totally professional. knowledgeable, competent and efficient. They were clean and caring and after each day they protected the whole worksite. Without a doubt, we would recommend them for all your basement waterproofing needs.Posted on Google Peter WebbTrustindex verifies that the original source of the review is Google. I called acm after finding water in the basement. Mark answered the call and quickly helped diagnose the issue. He guided me to check baseboard and sure enough a broken valve was causing this leak. It's good to find someone to help a homeowner without rushing to take their money. It's good to find a honest business man
Basement Water Solutions
That fuzzy growth on your floor joists isn’t just unsightly—it’s a warning. When mold or mildew appears in your crawl space, you’re not dealing with a cleaning problem. You’re dealing with a water and humidity problem.
Long Island’s coastal humidity and high water table create perfect conditions for crawl space mold growth. From Great Neck to Montauk, we see the same pattern: moisture enters the crawl space, humidity builds, and mold takes hold. The spores are everywhere—they just need moisture to thrive.
At ACM Basement Waterproofing, we fix the underlying moisture and drainage issues that allow mold to grow in the first place. Because here’s the truth: you can scrub away mold today, but without proper crawl space waterproofing, it’ll be back next month. We are the crawl space waterproofing experts near you to address your crawl space mold and mildew.
We make it simple, affordable, and stress-free — with guaranteed results.
Mold in your Long Island crawl space isn’t random—it’s predictable.
Several factors create the perfect storm for growth:
Groundwater seepage pushes through foundation walls and floors, especially during Long Island’s wet seasons. That concrete isn’t waterproof—moisture passes right through.
Poor drainage means water pools around your foundation instead of flowing away. Every rain adds more moisture to your crawl space environment.
High humidity from Suffolk County summers creates condensation on cool crawl space surfaces. That “sweating” provides enough moisture for mold colonies.
Plumbing leaks go unnoticed for months in crawl spaces. A small drip creates major mold problems over time.
Inadequate air movement traps moisture. Stagnant air in your crawl space keeps humidity levels perfect for mold growth.
Surface cleaning won’t solve these issues. Professional crawl space waterproofing addresses the source, not the symptom. We eliminate the conditions that mold needs to survive with our Long Island crawl space waterproofing near you.
Crawl space mold doesn’t stay in the crawl space—it affects your entire home through the “stack effect.” As warm air rises and exits through the home of your Long Island home to your roof, it pulls air up from below, carrying mold spores, moisture, and musty odors into your living space.
Structural damage accumulates silently: Wood rot weakens floor joists—we’ve seen them crumble when touched. Insulation becomes waterlogged and useless, falling in sheets from between joists. Metal components rust, including joist hangers and HVAC equipment. Your foundation itself can weaken as moisture degrades concrete over time.
Indoor air quality suffers immediately: That musty smell permeating your first floor? That’s mold. Family members experience increased allergies, respiratory issues, and headaches. The humidity from your crawl space makes your whole house harder to cool in summer and heat in winter, driving up energy costs. That’s not just uncomfortable—it’s unhealthy.
You don’t need to crawl under your house to spot problems. These signs indicate crawl space mold issues:
Visible evidence: Green, black, or white fuzzy growth on wood joists. Discolored insulation hanging or falling down. Dark staining on foundation walls.
Sensory clues: Musty odor in your home, especially on the first floor. Stronger smell during humid weather or after rain. Allergies that improve when you leave home.
Structural symptoms: Floors that feel soft or bouncy when walked on. Doors and windows sticking more than usual. Gaps appearing between walls and floors.
Moisture indicators: Condensation on crawl space surfaces. Standing water or persistent damp spots. Efflorescence (white powder) on foundation walls.
If you notice any of these in your Long Island home, mold is already established. The longer you wait, the more expensive the solution becomes. Call an expert crawl space waterproofer near you like ACM Basement Waterproofing.
We don’t mask mold problems—we eliminate them. ACM’s crawl space waterproofing Long Island homeowners trust addresses the root cause: moisture.
Interior drainage systems capture water before it enters your crawl space. We install French drains where water actually flows, not just around the perimeter. This prevents pooling and reduces hydrostatic pressure.
Sump pump installation removes collected water automatically. We size pumps for Long Island’s rainfall, not minimum specifications. Your crawl space stays dry even during nor’easters.
Battery backup sump pumps keep working when power fails—exactly when you need them most. Storm knocks out power? Your crawl space stays protected.
Discharge line protection ensures water leaves and stays gone. We prevent freezing, blockages, and backflow that reintroduce moisture.
Crawl space support jacks restore structural integrity where water damage has occurred. We don’t just dry things out—we repair the damage moisture caused.
Each component works together, creating a crawl space environment where mold cannot survive. No moisture means no mold—it’s that simple.
Long Island’s geography makes crawl space moisture problems worse than almost anywhere else. We’re surrounded by water, built on sandy soil that doesn’t drain well, and subject to coastal storms that dump inches of rain in hours.
Suffolk County challenges: High water tables mean groundwater sits just below your crawl space. Sandy soil shifts and settles, creating foundation cracks. Coastal storms bring both rain and storm surge.
Nassau County issues: Dense clay soil holds water against foundations. Aging infrastructure means more groundwater intrusion. Higher population density limits drainage options.
Both counties in Long Island experience humidity levels above 70% for much of summer. Your crawl space becomes a terrarium—warm, wet, and perfect for mold growth.
Add Long Island’s temperature swings—freezing winters, humid summers—and you get constant condensation cycles. Without proper crawl space waterproofing, Long Island homes fight a losing battle against moisture.
Family-owned since 1991, ACM understands Long Island crawl spaces because we’ve been under thousands of them. From Levittown ranches to Gold Coast estates, we’ve solved every crawl space water problem in Long Island imaginable.
We’re not a Long Island mold remediation company near you that just wipes surfaces and leaves. We’re waterproofing professionals who eliminate the moisture that allows mold to grow. Licensed, insured, and trusted across Suffolk and Nassau counties, we fix the problem once—correctly.
Our approach differs from franchises and out-of-state companies. We know that Freeport flooding differs from Huntington humidity. We understand why Great Neck groundwater behaves differently than Riverhead’s. This local Long Island crawl space waterproofing expertise means solutions designed for your specific area, not generic fixes.
When you need crawl space waterproofing, Long Island homeowners choose ACM because we deliver permanent solutions, not temporary patches.
What causes mold in crawl spaces in Long Island?
Moisture is the primary cause. Whether from groundwater seepage, plumbing leaks, or high humidity, mold needs moisture to grow. Long Island’s climate provides plenty of all three. Proper waterproofing and drainage eliminate these moisture sources. You need a crawl space waterproofer near you.
Is crawl space mold dangerous in my Long Island home?
Yes. Mold releases spores and mycotoxins that trigger allergies, asthma, and respiratory issues. Structural damage from mold can compromise your home’s safety. The “stack effect” pulls contaminated air into living spaces, affecting your family’s health daily.
Can Long Island waterproofing prevent mold?
Absolutely. Mold cannot grow without moisture. Professional crawl space waterproofing eliminates water sources and controls humidity. No moisture means no mold—our systems maintain dry conditions year-round.
How do I know if my Long Island crawl space needs waterproofing?
Signs include musty odors, visible mold, standing water, high humidity, rusty metal components, or deteriorating wood. If you notice any moisture indicators or have had past water problems, your crawl space needs waterproofing.
Does insurance cover crawl space mold for my Long Island crawl space?
Unfortunately, often not. Insurance typically excludes gradual water damage and mold. They consider it a maintenance issue. That’s why prevention through waterproofing costs far less than mold remediation and structural repairs.
Don’t let mold take over your Long Island home – contact a crawl space waterproofing company near you. ACM provides free, thorough crawl space inspections throughout Nassau and Suffolk counties. We’ll identify moisture sources, assess current damage, and recommend the right waterproofing solution for your specific situation.
Our inspection reveals:
Stop treating symptoms. Fix the cause. Call ACM Basement Waterproofing today for your free crawl space waterproofing consultation. Protect your family’s health and your home’s value with permanent moisture solutions.
Your Long Island home deserves better than mold. Let’s solve your crawl space moisture problem once and for all.
We make it simple, affordable, and stress-free — with guaranteed results.
*50% Off Materials Discount applicable to new projects over $10,000
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