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
Crawl space water issues plague many Long Island homeowners, leading to structural damage, mold growth, and decreased home value. Understanding the common causes of crawl space moisture helps you protect your Long Island home and maintain a healthy living environment. Here’s what every Long Island homeowner needs to know about the sources of crawl space water problems.
We make it simple, affordable, and stress-free — with guaranteed results.
Crawl space water rarely comes from a single source. In most Long Island homes, it is a combination of factors working together, from the soil and water table beneath your foundation to the gutters and grading around it. Knowing what is actually letting water in is the key to stopping it for good. Here are the most common causes ACM finds in crawl spaces across Nassau and Suffolk County.
When soil around your foundation becomes saturated with water, it creates intense pressure against your crawl space walls. This hydrostatic pressure forces water through even the smallest openings in your crawl space floors and walls. Long Island’s rainfall and dense soil composition make homes particularly vulnerable to this destructive force, leading to serious crawl space water issues if left unchecked.
Natural groundwater movement beneath your Long Island home can lead to persistent moisture problems in your crawl space. This continuous moisture intrusion often creates a chronically damp environment in unprotected crawl spaces, perfect for mold growth and pest infestation.
Many areas of Long Island experience naturally high water tables, particularly along the coast and in low-lying areas. As the water table rises, water in the soil presses against your crawl space floors and eventually makes its way into your crawl space, creating dampness issues.
Improper landscape grading around your home directs water toward your foundation instead of away from it. Even a slight slope toward your house can channel significant amounts of rainwater and snowmelt into your crawl space. This common issue on Long Island properties often results from natural soil settling or improper initial construction grading. To keep water away from your crawl space, you need to have your yard regraded.
Damaged or incorrectly installed gutter systems fail to properly channel water away from your Long Island home’s foundation. When gutters become clogged with leaves, ice, or debris – a common problem during Long Island’s seasonal changes – water overflows directly beside your foundation; this overflowing water saturates the soil around your crawl space, leading to water infiltration in the crawl space.
Cracks in your crawl space walls provide direct pathways for water to enter your crawl space. These cracks can develop from settling, soil pressure, or natural aging of foundation materials. Long Island’s freeze-thaw cycles and shifting soil conditions contribute to crack formation, making crawl space repair essential for preventing water intrusion.
Deteriorated or improperly installed crawl space windows often become entry points for water. Old windows can collect water during heavy rains, while damaged seals or frames allow moisture to seep into your crawl space. Long Island’s exposure to coastal storms makes these vulnerabilities particularly problematic.
Long Island’s vulnerability to severe weather events, including nor’easters and tropical storms, puts homes at risk of crawl space flooding. During these events, overwhelming amounts of water can quickly inundate crawl spaces through various entry points. Even homes not in designated flood zones can experience significant crawl space water during extreme weather conditions.
A wet crawl space does not stay contained to the crawl space. Standing moisture rots wooden joists and beams, which leads to sagging, sloping floors in the rooms above. Damp, dark conditions invite mold and mildew, and because a large share of the air you breathe upstairs starts in the crawl space, those spores and musty odors travel into your living areas.
Excess moisture also draws pests like termites, carpenter ants, and rodents that are happy to nest in a damp space. Over time, the structural damage adds up, your energy bills climb as humid air strains your HVAC system, and your home’s resale value drops. What starts as a little dampness becomes an expensive repair. The good news is that every cause on this page has a proven fix.
Once we identify what is letting water into your crawl space, ACM matches the right solution to the cause:
Most crawl spaces need a combination of these, and ACM builds a plan around what your home actually requires.
Don’t let crawl space water issues compromise your Long Island home’s structure and your family’s health. Understanding these common causes is the first step toward effective prevention and mitigation. Contact our experienced crawl space waterproofing team for a thorough crawl space inspection and customized solutions to keep your Long Island home dry and healthy.
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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