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Best basement waterproofing pros near Sullivan, NH

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Top-Rated Basement waterproofing pros in Sullivan - Updated Nov 2026

Avatar for Northern Basement Systems
Northern Basement Systems
4.6(
21
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Sullivan, NH and surrounding areas

Approved

In business since 2010

Free estimates

Warranties offered

"Paul Swann evaluated our foundation problem and referred us to an engineer who provided a detailed repair plan. Unfortunately, the nature and scope of the proposed repair plan was outside the parameters of what Northern Basement System's themselves could provide. We appreciated their honesty and have been looking for a contractor to take on the project."
Additional Photos
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+25

Response time1 day
7 neighbors recently requested a quote
Recommended by88%of homeowners
Avatar for LeBlanc Basement Waterpoofing, LLC
LeBlanc Basement Waterpoofing, LLC
5.0(
3
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Sullivan, NH and surrounding areas

Approved

In business since 2007

Free estimates

Emergency services offered

"I was impressed with his knowledge and professionalism. He installed a French drain system with a vapor barrier on the walls. He prepped the area to protect our belongings, made sure everything was cleaned up after the end of each day, and provided exceptional service and quality. I would highly recommend him!"
Ion sump pump
Airtight solid sump cover
Ashburnham, MA.
Ashburnham, MA.
Ashburnham, MA.

+28

Response time1 day
8 neighbors recently requested a quote
Recommended by100%of homeowners
Avatar for Groundworks
Groundworks
4.6(
26
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Sullivan, NH and surrounding areas

Approved (Corporate)

In business since 1996

Free estimates

Warranties offered

"Joe,James and Bobby did an excellent job replacing the sump pump And drains. My husband and I were so impressed with their abilities and how hard working they were. I would highly recommend Ground works Manchester to anyone who needs the same work done. Thanks to all the gentlemen for their professionalism and work ethic"
Foundation
Foundation
Foundation
Basement
Basement

+16

Response time12 hrs
197 neighbors recently requested a quote
Recommended by56%of homeowners
Avatar for Freedom Framing and More, LLC
Freedom Framing and More, LLC
4.3(
14
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Sullivan, NH and surrounding areas

Approved

In business since 2014

Free estimates

Warranties offered

"I had a great experience with Freedom Framing! Matthew was very easy to work with and did a great job for a great price! Matthew is not only a great carpenter he is a very good project manager, ensuring the supporting contractors needed to complete the work arrived on time and performed top quality work. I would strongly recommend him for any construction work needed. I will be calling Matthew for the next project on my list! Excellent job Matthew! Thank you very much!"
Before
During
Wrapping up
Finished
Prep

+34

Response time2 days
Response rate95%
Recommended by84%of homeowners
Avatar for Basement Solutions LLC
Basement Solutions LLC
New to Angi
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Sullivan, NH and surrounding areas

Approved

In business since 2025

Free estimates

Warranties offered

We pride our company on reliability, integrity and quality work. We are experts in our trade. We look forward to earning your business! We specialize in concrete crack repair and injections, basement waterproofing, sump pump installations, basement and egress window installations, crawlspace repair, moisture control, foundation repair and so much more.\nCall us today for a free estimate.

Egress
Egress
Egress
Sump Pump
Perimeter System

+4

13 neighbors recently requested a quote
Showing 1-10 of 47
Basement Waterproofing FAQs, answered by experts

Ductwork sweats due to a temperature difference between the air inside the ducts and the surrounding air, similar to how a cold drink develops condensation in the heat. This sweating is a sign that your HVAC system is not operating at peak efficiency. The best way to keep ductwork from sweating is to wrap it in proper insulation, which also improves your system's energy efficiency. Another option is to close off your crawl space and install a dehumidifier to dry the air and lower its dew point.

Yes, a crawl space can add value to your home. However, there is a higher chance of it adding value if it is an enclosed crawl space, as this reduces issues caused by excess moisture in the home. That being said, a basement does add more value than a crawl space.

Water that pools under pavers can erode the soil foundation and weaken the paver structure. In some situations, it can also cause mold and mildew growth. If that happens, you may need to start budgeting for the cost to build and install a patio to replace the damaged one.

There are a few downsides to a wet room, the most important of which is the risk of mold growth from the moisture and humidity. Standard bathrooms can have the same issue, but wet rooms are more likely to experience problems because water is less carefully contained. You also have less privacy since the entire bathroom is open, and the room must include waterproofing, which makes wet rooms more expensive to install than regular bathrooms.

Some disadvantages of crawl spaces are mostly regarding the air itself—moisture build-up and poor ventilation, which can cause problems both in the house and underneath it, even damaging the foundation itself. Crawl spaces are difficult to access and often invite unwanted pests during the hot summer months and the cold winter ones. These hard-to-seal spaces are also susceptible to water damage during periods of heavy rain or melting snow.

The Sullivan, NH homeowners’ guide to basement waterproofing services

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