Long Island’s Best Basement Waterproofing Company
- Honest, No-Pressure Pricing & No-Obligation Estimates
- Decades of Experience, Thousands of Homes Protected
- Locally Run, Family-Owned, Fully Licensed & Insured
Get 50% Off Materials!
50% Off Materials!
Until September 30th, 2026, take advantage of our End of Summer Sale and receive 50% off materials for new projects over $10,000. Don't let moisture or foundation problems get worse. Whether you're dealing with a leaking basement, a damp crawl space, or foundation damage, ACM Basement Waterproofing delivers proven solutions backed by decades of experience. Schedule your free Long Island home inspection today and ask about financing options.
Waterproofing Basements In Long Island for 30 Years!
ACM Basement Waterproofing is a family-owned and operated business providing expert basement waterproofing, foundation repair, and crawl space waterproofing throughout our Long Island service area.
We help you make the best decision that’s right for your basement water problems and your budget.
Call us at 631-581-0600 to schedule a free inspection and quote. We look forward to meeting you and to solving your basement, foundation, and crawl space problems.
Our Basement Waterproofing & Foundation Repair Services Across All Of Long Island
Basement
Waterproofing
Your basement is part of your Long Island home, but water or moisture can make it a battleground. A wet basement can result in mold, rot, insects, rodents, and property damage. But ACM’s Long Island basement waterproofing system protects your basement. We use non-intrusive, effective interior french drains, sump pumps, and discharge lines to keep your basement safe and dry. If you have basement water problems, call Long Island’s basement waterproofing company – ACM.
Crawl Space
Waterproofing
Not every Long Island homeowner has a basement. Instead, you could have a crawl space. Unfortunately, crawl spaces fall prey to the same issues as basements – water, mold, insects, and rot. But, unlike a basement, crawl spaces often go unseen, but that doesn’t mean they should be ignored. The humid, mold-spore-filled, poor air from your crawl space is sucked up into the rest of your home, where it can cause health issues. A Long Island crawl space waterproofing system can make all the difference by protecting both your crawl space and your upstairs.
Foundation
Repair
When you walk down into the basement of your Long Island home, do you notice cracks along your basement walls? If you look closer, is the foundation wall bowing inward? If so, you need ACM, Long Island’s foundation repair company. Using proven, effective foundation repair methods, we can repair bowing foundation walls before the issue grows more severe and more expensive. Reach out to us today to schedule your Long Island foundation repair quote. Let us help secure your foundation.
Sump Pump
Installation
A sump pump is the engine that keeps your basement or crawl space protected when water begins to collect. ACM installs premium Blue Angel by Wayne sump pump systems, trusted for their dependable performance and long-term reliability. Whether you’re replacing an aging pump or installing a new waterproofing system, our team provides fast, professional installation and optional battery backup protection. Trust Long Island’s experienced sump pump installation specialists to protect your home for years to come.
French Drain
Installation
Excess groundwater around your foundation doesn’t have to become a costly problem. ACM installs custom interior French drain systems throughout Long Island to intercept water before it can damage your home. Using premium materials, expert craftsmanship, and proven drainage designs, our systems provide permanent protection backed by a lifetime warranty. With fast installation and decades of experience, ACM is Long Island’s trusted choice for professional French drain installation.
Foundation
Crack Repair
Cracks in your foundation or basement walls are often an early warning sign of foundation movement or structural stress. Left untreated, they can continue to grow and lead to more extensive repairs. ACM provides expert foundation and basement crack repair throughout Long Island using proven techniques, premium materials, and decades of experience. We deliver permanent repair solutions that restore your home’s strength, stability, and long-term structural integrity.
Thousands of Long Island Basements & Crawl Spaces Waterproofed
For over twenty years, ACM Basement Waterproofing has provided expert basement waterproofing, crawl space waterproofing, and foundation repair services to thousands of homeowners and business owners throughout Long Island.
We are one of only three companies in New York that have received the Basement Health Association’s prestigious star award. When you choose ACM, you are choosing reliable, top-notch solutions.
Recognized, Reviewed & Awarded Waterproofing Services Near You For Long Island Homeowners
Basement Waterproofing & Foundation Repair In Suffolk & Nassau County
Waterproofing Long Island homes is inappropriate for DIYers and novice waterproofing companies because there is no one-size-fits-all solution. The soil composition, ground layout, and building structures of Long Island are unique. To solve the issue, you need custom solutions from an expert waterproofer serving Suffolk a Nassau County. You Need ACM Basement Waterproofing.
Some of the Long Island Cities We Serve
Some of the Long Island Cities We Serve
Long Island Waterproofing - In the Know
Do you need basement waterproofing? Our DIY home inspection checklist shows you the warning signs of an unhealthy basement.
Our Crawl Space, Basement Waterproofing, & Foundation Repair Jobs in Long Island
From foundation repair in Freeport to basement waterproofing in Garden City, we’ve protected thousands of Long Island homes for decades. Every basement we’ve dried, every crawl space we’ve protected, and every foundation we’ve repaired tells a story—families in Nassau and Suffolk counties who no longer worry when storms hit.
These aren’t just jobs to us. They’re your neighbors’ homes, from modest Levittown ranches to North Shore estates, each requiring the right solution for their specific water problems. Take a look at how we’ve helped Long Island homeowners transform wet, vulnerable spaces into dry, protected foundations that last.
- All
- Mono
- Di
- Tri
- Tetra
- Penta
- Hexa
Long Island Chooses Us
I bought my house 24 years ago, and for 24 years I lived with water coming in to my finished basement… Since the French Drain System was placed I have not had 1 drop of water coming into my basement.
-Linda R.
Kristina RD
We used to have constant flooding in the basement during heavy rainfalls. Mark came in and they installed a french drain and sump pump that has solved our flooding problem. We have not had a water problem in over a year. Super friendly and great work! Thank you!
Terence E.
I can’t recommend higher the great work done by Mark and his team. Mark is honest and reliable. He didn’t try to convince or sell me things that I didn’t need. He knows all there is to know about keeping your basement dry. His crew was great. They did a wonderful job, and left the house spotless.
Allen B.
ACM did a great job installing a french drain system in my basement a few weeks ago. Now that we’ve had a few heavy rains I can report that my basement is completely dry. Mark and his crew were terrific.
Really a well oiled machine. They knew exactly what they were doing and were very helpful and extremely nice. In short a very clean professional job by a great crew at a fair price.
Jody M.
Mark is a great person to deal with. He is very responsive and has a lot of experience. He is honest and really cares about what he does.
He has done several projects on my home including servicing my sump pumps and fixing problem with water coming in my basement entrance. I highly recommend using ACM.
Mary D.
ACM did a marvelous job! My basement flooded every rainstorm. Now..as they told me : not a drop! Great relief..
Athena G.
The work that ACM did in my basement is incredible! I loved that they are a family small business and was happy to support them. The entire experience was amazing from the initial consultation with Mike to job completion. The crew was extremely respectful, and very diligent in their work. They were very clean and organized and even swept the floor when they left each night. Highly recommend this group of professionals!
Fallon D.
ACM was amazing!! The owner was so knowledgeable . He is so hands-on throughout all aspects of the construction we had in our basement. He even came back to check everything several weeks later (on his own) because he wanted to make sure everything was running smoothly (which it absolutely was). He cares about his work and his customers. They really did an incredible job covering everything in the basement prior to the construction and cleaning up after. I was extremely happy with everything. Basement is thankfully dry now thanks to ACM.
Learn More About Basement Waterproofing & Foundation Repair in Long Island
Have questions? How did water get into your basement, what issues can mold in your crawl space cause, are stair step cracks in my foundation wall a serious problem? Read through our Knowledge Center for answers.
How Do You Waterproof a Basement
How Did Water Get Into My Basement?