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Crawl Space Repair

Long Island Chooses Us

    
 
 
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   Linda Weiss 
 
 
 
 Trustindex 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 smith 
 
 
 
 Trustindex 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 Todaro 
 
 
 
 Trustindex 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.
  
 
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   Linda Russo 
 
 
 
 Trustindex 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.
  
 
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   Maria Lacoste 
 
 
 
 Trustindex 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.
  
 
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   William Rothstein 
 
 
 
 Trustindex 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.
  
 
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   Links2282 
 
 
 
 Trustindex 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.
  
 
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   Peter Webb 
 
 
 
 Trustindex 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

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Basement Water Solutions

Proven Crawl Space Water and Repair Solutions in Long Island

We Solve Wet Crawl Space or Sagging Floor Problems Near You

You may notice the warning signs already: standing water under the house after it rains, a musty smell drifting up into your living space, or floors that feel soft and bouncy when you walk across them.

Maybe humidity is creeping into the rooms above, your energy bills are climbing, or you have started seeing mold along the joists. These are not problems that fix themselves. A damp crawl space only gets worse, and the longer it sits, the more it costs to repair.

ACM handles wet crawl space repair, moisture control, and full crawl space waterproofing for Nassau and Suffolk County homes, and we do it right the first time.

Protect Your Home Today

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

Signs You Need Crawl Space Waterproofing

Not sure if your crawl space is a problem yet? Here is what to look for:

Standing water, puddles, or damp soil under your home
A musty, earthy smell in the crawl space or the rooms above it
White, chalky residue (efflorescence) on foundation walls
Wood rot, soft spots, or visible mold on floor joists and beams
Sagging, sloping, or bouncy floors
Condensation on pipes, ductwork, or insulation
Sticking doors and windows on the first floor
Worsening allergies, asthma, or stale air inside the house
Higher heating and cooling bills than you used to pay

If any of these sound familiar, your crawl space is letting in moisture. The good news is that every one of these issues has a fix, and ACM can walk you through exactly what your home needs during a free inspection.

How We Fix Wet Crawl Space Issues

Crawl Space Waterproofing

Crawl space waterproofing is one of the most effective, efficient, and affordable ways to protect your Long Island home from moisture, mold, and structural damage. ACM specializes in complete crawl space waterproofing solutions, including drainage systems, sump pumps, and moisture control systems designed to keep your crawl space clean, dry, and protected year-round.

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Crawl Space Encapsulation

Wondering whether your crawl space needs encapsulation or waterproofing? If your crawl space has standing water or groundwater intrusion, waterproofing should always come first. Learn why controlling the water source is the key to a dry, healthy crawl space and why ACM Basement Waterproofing focuses on permanent waterproofing solutions for Long Island homes.

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Interior French Drains

Interior perimeter French drains in the crawl space are one of the most effective, efficient, and affordable solutions for keeping your crawl space dry in your Long Island home. The durable drains collect any entering water and funnel it to a crawl space sump pump. ACM specializes in advanced French drain installation to protect your crawl space.

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Crawl Space Sump Pumps

A sump pump is a vital component for crawl space waterproofing. ACM Crawl Space Waterproofing is Long Island’s trusted expert in professional sump pump installation for crawl spaces. The sump pump collects and pumps out any water captured in the french drain perimeter system. ACM only provides long-lasting, high-quality sump pump solutions.

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Battery Backup Pumps

A sump pump is essential for Long Island crawl space waterproofing, but it won’t function during a power outage, leaving your home vulnerable during heavy rains. ACM recommends installing a battery backup sump pump to ensure continuous protection. Your crawl space and home stays protected even when you don’t have power.

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Yard Grading & Leveling

Exterior factors can play a big role in crawl space water problems. Poor yard grading allows water to pool near your crawl space, seeping into your crawl space and causing damage. ACM provides expert yard grading and leveling services for your Long Island property. We create a 5% slope away from your foundation using proper soil types to ensure drainage while preserving your landscaping.

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Restoration Equipment Rental

Before your crawl space can be waterproofed, any standing water needs to be removed and the space needs to dry out so the waterproofing system can be installed correctly. If your crawl space already has water in it, we offer carpet fan rentals and dehumidifier rentals to help dry it out.

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Why Long Island Crawl Spaces Flood

Crawl spaces on Long Island face conditions that make water problems common. Much of the area sits on sandy soil with a high water table, so groundwater is never far from your foundation.

Heavy rain from Nor’easters and summer storms overwhelms yards that do not drain well, and a lot of older Long Island homes were built with vented crawl spaces that pull damp outside air right in. Add poor grading or aging foundation walls, and water finds its way in.

Knowing why it happens is the first step. ACM looks at the full picture, inside and out, and builds a waterproofing plan that fits your home and your property.

Crawl Space Waterproofing FAQs

How much does crawl space waterproofing cost on Long Island?
Cost depends on the size of your crawl space and what it needs, whether that is a French drain and sump pump, or a combination of solutions. Every home is different, which is why ACM gives you a free, no-pressure estimate before any work begins, so you know exactly what you are paying for.

Is crawl space waterproofing worth it?
Yes. A wet crawl space damages your floor joists, invites mold, raises your energy bills, and hurts your home’s air quality and resale value. Waterproofing costs far less than the structural repairs you face if you ignore it, and it protects the value of your home.

How long does crawl space waterproofing take?
Most crawl space projects are finished in one to three days, depending on the size of the space and its condition. ACM gives you a clear timeline upfront so there are no surprises.

Can a wet crawl space affect the rest of my house?
It can. Around half the air you breathe upstairs starts in the crawl space, so moisture, mold spores, and musty odors travel up into your living areas. A damp crawl space also leads to sagging floors, sticking doors, and wood rot that affects the whole structure.

Do you offer free crawl space inspections?
Yes. ACM provides free crawl space inspections and estimates throughout Nassau and Suffolk County. We will assess the space, explain what we find, and recommend the right solution with no obligation.

How do I know which solution my crawl space needs?
That is what the free inspection is for. Depending on what we find, your home may need interior drainage, a sump pump, better yard grading, or a combination. ACM walks you through the options and helps you choose what makes sense for your home and budget.

We Are Long Island’s Crawl Space Waterproofing and Repair Company

ACM proudly serves homeowners across Long Island, including Nassau County and Suffolk County. Wherever you are on the Island, we are ready to help you get a dry, healthy crawl space.

If your Long Island home is dealing with crawl space water issues, trust ACM – your go-to waterproofing contractor for long-lasting solutions. Call us today to schedule your free estimate and get permanent crawl space protection.

Protect Your Home Today

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