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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
6 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 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

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

Roughing in and connecting utilities are the hardest parts of finishing a basement, and they’re the parts we typically don’t recommend doing as a DIY project. Unfortunately, your finishing timeline can be extended by weeks while you wait for contractors and inspectors to install electrical wiring, plumbing lines, and heating/cooling equipment and carry out inspections.

Water damage to concrete is often gradual and can take months, if not years, for a concrete structure to be fully destroyed. The process often starts with cracks on the surface, followed by sinking slabs and eventually crumbling cement. Therefore, it is important to repair minor damages early to prevent the situation from worsening.

Plan on cleaning your crawl space at least once a year, though twice a year is ideal. During the cleaning, remove any debris or dust and check for potential issues like pest infestations or water damage. The sooner you catch these issues, the easier (and cheaper) it will be to fix them.

No, everything doesn’t get wet if the bathroom is well-designed and the fixtures are properly installed. It’s important that the floor of a wet room drains correctly, and proper waterproofing and slip-resistant flooring are used to avoid creating slipping hazards. Since the shower isn’t housed in an enclosed space, you’ll need to make sure the towel rack and toilet paper holder are placed in areas where they won’t get wet.

Crawl spaces are the more desirable option overall because they provide additional space for storage and utilities, but they are more expensive to install and maintain. Slab foundations are considered a better option in warmer climates where the depth of the frost line isn’t an issue because they’re more affordable, but crawl spaces are better in areas where the frost line is deep or where flooding can be an issue.

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.