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Best basement waterproofing pros near Cos Cob, CT

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TRUSTED BY COS COB, CT HOMEOWNERS

  • Average homeowner rating star icon4.7
    Average homeowner rating
  • Verified reviews icon46
    Verified basement waterproofing services reviews

Top-Rated Basement waterproofing pros in Cos Cob - Updated Nov 2026

Avatar for American Dry Basement Systems, LLC
American Dry Basement Systems, LLC
4.9(
118
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Cos Cob, CT and surrounding areas

Approved

In business since 1997

Free estimates

Credit card accepted

"I had my basement waterproofed almost 3 years ago by them and I had no issues since then with the basement flooding regardless of how much it rains. I highly recommend using American Dry Basement!"
Drainage Trench
Jackhammer
Mixing SuperCrete
Compress Wash Stones
Spreading SuperCrete

+7

Response time11 hrs
3 neighbors recently requested a quote
Recommended by66%of homeowners
Avatar for Dirty Deeds Basement Waterproofing
Dirty Deeds Basement Waterproofing
5.0(
4
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Cos Cob, CT and surrounding areas

Approved

In business since 2012

Free estimates

Emergency services offered

"Dean and his crew were professional, reliable, extremely neat/clean and went above and beyond, often, to make the sure work was completed to my satisfaction. They did small things not even required to make sure the entire basement area was much more than even expected. The basement has never been so dry in the 40 years I have lived here. I would hire them again in a heartbeat."
Additional Photos
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+24

Response time7 hrs
7 neighbors recently requested a quote
Recommended by100%of homeowners
Avatar for Groundworks
Groundworks
4.9(
13
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Cos Cob, CT and surrounding areas

Approved (Corporate)

Super Service Award Winner

In business since 2025

Free estimates

Warranties offered

Groundworks is the North America's leading and fastest-growing foundation repair and water management solutions provider. Groundworks is a vertically integrated company with its own manufacturing operations and a world-class software solution, allowing us to serve our customers more effectively. From the first phone call to the annual maintenance offered, our customers have peace of mind knowing we're there with one mission to repair, protect and improve their home. For state licenses visit Groundworks.com/licensing

Foundation
Foundation
Foundation
Concrete
Concrete

+16

391 neighbors recently requested a quote
Avatar for AG Property Maintenance, LLC
AG Property Maintenance, LLC
4.6(
12
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Cos Cob, CT and surrounding areas

Approved

In business since 2012

Free estimates

Offers commercial services

"Pedro and team solved an ongoing pond drainage issue that was able to be resolved. Many companies came and charged us money for half a job and this was not the case with AG. They were professional, proficient and quickly got to the source of the problem in one day. Prices were fair and they did not have to come back as they had all the supplies they needed to start and finish the job which is very rare for a major culvert issue like this one."
Brookfield ct
Brookfield ct
Brookfield ct
Brookfield ct
Brookfield ct

+4

Response time2 days
4 neighbors recently requested a quote
Recommended by100%of homeowners
Avatar for AA Outdoor Services, LLC
AA Outdoor Services, LLC
3.9(
33
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Cos Cob, CT and surrounding areas

Approved

In business since 1990

Free estimates

Small jobs welcome

"Vincent did an absolutely beautiful job on my cement and asphalt driveway. Their craftsmanship was top-notch. They finished the job quickly, and left the work area clean when they were not there. They stayed in touch throughout the process, and they take tremendous pride in their work. I have worked with hundreds of contractors over the years and these folks are among the very best and most reliable. Cannot say enough good things, also the prices were competitive, and they delivered a better quality of work than I would expect for a similar price."
Driveway in New Haven (West Haven)
Rear entrance and parking area (West Haven)
Rear entrance and parking area (West Haven)
Step repair (West Haven)
Step repair (West Haven)

+61

Response time9 hrs
Recommended by100%of homeowners
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Basement Waterproofing FAQs, answered by experts

Access to commercial-grade products and equipment, ensuring thorough coverage and long-lasting protection.

Generally, moisture barrier padding costs $0.75 to $1.50 per square foot, varying by brand and mix. That’s a lot more than standard padding, which runs $0.25 to $0.90 per square foot. The price difference between these two options might seem steep, but think of it as insurance against future carpet replacement costs and subfloor damage. If you have pets or kids, that extra investment in high-risk areas like your living room often pays off.

No, you don’t want your crawl space to be wet because water and even moisture in the air under your home can attract insects and rodents, decrease your indoor air quality, increase your energy bills, promote mold growth, and even lead to structural damage. If you notice any signs of water or humidity in your crawl space, you should get the issues addressed immediately by contacting a professional. They can remove moisture and will know how to waterproof your basement to prevent ongoing problems.

The best way to ensure the ground next to your home’s foundation drains properly is to divert water away from it as much as possible. While a flood wall can stop water from entering the house, gutters and spouts can help direct rainwater and melting snow away from the foundation. Keep your gutters as clear as possible from dead leaves and other yard debris so they can effectively divert water from your house. Add extenders to the spouts so the water runs out and away from your home, not into the surrounding soil.

One handy thing about whole-house dehumidifiers is, once installed, you don’t have to worry about placement or changing the dehumidifier’s position. But if you are using a portable dehumidifier, we suggest keeping it away from walls, vents, and furniture. It needs a central, unobstructed spot with access to lots of air to do its job.

The Cos Cob, CT homeowners’ guide to basement waterproofing services

From average costs to expert advice, get all the answers you need to get your job done.