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
If you’ve noticed puddles in your Long Island basement after rain or water pooling along the walls, you’re not alone. Standing water in basements is one of the most common issues we see in homes across Nassau and Suffolk Counties.
It usually starts small. A damp patch on the concrete that never quite dries. A shallow puddle near the foundation wall. Water that appears after a storm and seems to go away on its own.
A lot of Long Island homeowners brush it off as “just how basements are” or put it on the back burner. But here’s the reality: standing water almost always signals an ongoing drainage issue or groundwater pressure problem that won’t resolve itself. Left alone, it typically gets worse.
At ACM Basement Waterproofing, we’ve spent years helping homeowners throughout Long Island figure out exactly where their basement water is coming from and fix it for good.
We make it simple, affordable, and stress-free — with guaranteed results.
These two problems are related, but they’re not the same thing.
Standing water tends to show up as recurring puddles or persistently damp spots on your basement floor. You might notice water pooling in the basement hours or even days after it rains. It comes and goes depending on groundwater levels and seasonal conditions.
Long Island basement flooding is a different story. When we talk about basement flooding, we mean inches of water rushing in during heavy storms or rapid snowmelt. If your basement fills up quickly when the weather turns, that’s flooding.
If sudden, heavy water intrusion sounds more like your situation, take a look at our page on basement flooding in Long Island for more on that specific issue.
This page is focused on standing water and the chronic conditions behind it.
There are a few reasons why basement water problems are so common on Long Island. It comes down to local geology, groundwater behavior, and the age of many homes in the area.
The high water table is a major factor. In much of Long Island, groundwater sits just a few feet below the surface. After rain or snowmelt, that water rises and pushes against your basement floor and foundation walls. You don’t need visible cracks for water to find its way in. It can seep through joints, porous concrete, and tiny openings you’d never notice.
Soil composition matters too. Sandy soil lets water travel sideways toward the foundation, while clay pockets trap moisture against basement walls. Many Long Island neighborhoods have a mix of both, which makes groundwater movement around your home unpredictable.
Older homes face additional challenges. Drainage systems installed 30 or 40 years ago can clog, crack, or simply stop working. Sump pumps installed in your Long Island home may be undersized for today’s storms or running on borrowed time. Small foundation cracks that aren’t visible from inside can still let water through when the pressure builds.
These conditions make standing water a recurring headache in both Nassau County and Suffolk County, especially in low-lying areas, near the coast, and along the South Shore and North Shore.
Sometimes it’s obvious. Other times, the signs are easy to miss until the problem has been going on for a while.
Here’s what to look for:
If any of this sounds familiar, it’s worth investigating before things escalate.
It’s tempting to shrug off a small puddle in the basement of your Long Island home. But groundwater pressure doesn’t take a break, and the damage adds up over time.
Repeated moisture weakens concrete and masonry. It can compromise your foundation and ruin any finished space you’ve invested in.
Standing water also creates the perfect environment for mold growth. Mold can take hold before you ever see visible damage, and once it does, it affects indoor air quality throughout your home. We cover this in more detail on our basement mold and mildew page.
There are safety concerns too. Water near electrical panels, outlets, or appliances creates real hazards. And if you’re thinking about selling your Long Island home someday, know that chronic basement water issues have to be disclosed. They can drag down your home’s value and scare off buyers. Fixing the problem now is almost always cheaper than dealing with long-term damage later.
Before calling a professional, most homeowners try a few DIY solutions. We get it. But while these might remove water in the moment, they don’t address what’s actually causing the problem.
Approaches that don’t hold up over time:
These treat the symptom, not the source. As long as groundwater pressure exists, the water will keep coming back.
Real solutions focus on one thing: intercepting groundwater and directing it away from your foundation before it ever reaches your basement floor.
For most homes on Long Island, this means installing an interior Long Island basement waterproofing and drainage system along the basement’s perimeter. These systems capture water right where it enters and channel it toward a sump pump for removal.
French drain systems are designed to relieve hydrostatic pressure and stop water from pooling on your floor.
Sump pumps do the heavy lifting, moving collected water out and away from your foundation. In areas prone to storms and power outages, battery backup systems provide an extra layer of protection when you need it most. Depending on your situation, we may also recommend targeted foundation crack repairs or improvements to how water discharges away from your home.
Question: Why do I have standing water in my Long Island basement when there are no visible leaks?
This is actually pretty common. Standing water often comes from groundwater pushing up through the basement floor or seeping in at the joint where the floor meets the foundation wall. On Long Island, the water table sits high enough in many areas that pressure builds under the slab after rain or snowmelt. Concrete is porous by nature, so water can move through it even without obvious cracks.
Question: Is standing water in my Long Island basement really that serious?
It can be, yes. Even small amounts of water cause problems if they keep returning. Over time, ongoing moisture weakens concrete, damages finishes, and creates conditions where mold thrives. Water near your floor can also create electrical and safety hazards. Dealing with it early is almost always easier and less expensive than waiting until the damage becomes obvious.
Question: How do I fix standing water in my Long Island basement for good?
Removing the water itself is just step one. To solve the problem permanently, you need to address where the water is coming from. For most Long Island homes, that means relieving groundwater pressure and redirecting water away from the foundation with a proper drainage system and a correctly sized sump pump. A professional inspection helps determine the right approach based on your home’s layout, soil conditions, and drainage patterns.
Question: Does standing water always mean I need full basement waterproofing?
Not necessarily. But if standing water keeps coming back, it’s a strong indicator that some level of waterproofing or drainage work is needed. A one-time incident might be related to something temporary, but water that returns after rain or cleanup usually points to a deeper issue. An inspection can help determine whether you need a comprehensive waterproofing system or a more targeted repair.
You should consider a professional inspection if:
Catching the problem early can prevent more serious damage later.
ACM Basement Waterproofing serves homeowners throughout Long Island, including Nassau and Suffolk Counties. We understand local soil conditions, groundwater behavior, and the challenges unique to coastal homes.
If you are dealing with standing water in your basement, we offer free inspections and honest recommendations tailored to your home.
Contact ACM Basement Waterproofing today to schedule your inspection and take the first step toward a dry, protected basement.
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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