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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
3 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 Green Home Solutions of North Central MA
Green Home Solutions of North Central MA
4.8(
13
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Sullivan, NH and surrounding areas

Approved

In business since 2021

Warranties offered

Credit card accepted

"Kenson was able to come in and do the work quietly as I was working from home. He explained all the steps and the possible remediation. Paying by cc did have a heavy charge, but otherwise everything was awesome."
Attic Mold Remediation - Fitchburg, MA
Mold Contamination in Attic
Living Room- Mold remediation - Lowell MA
Living Room Mold Remediation - Lowell, MA
Attic Mold Remediation - Derry, NH

+11

Response time12 hrs
Response rate90%
42 neighbors recently requested a quote
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

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

Some basement waterproofing methods can actually cause your water or moisture problems to get worse, which is why it’s so important to call in a professional who knows how to solve your underlying issue and use the appropriate waterproofing methods. An example of this would be applying latex waterproofing paint to the insides of your basement walls without fixing the water issue outside. Doing so can trap moisture in the basement walls, which can promote mold growth, peeling paint, and even damaged concrete. However, when done by a professional, the only downside to basement waterproofing is the up-front cost.

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.

As the first layer of water protection for your roof deck and the building materials below, underlayment is designed to prevent water damage, so it’s okay if it gets wet. However, you shouldn’t rely solely on underlayment for protection. If rain interrupts your roof project and you have all of the underlayment down, you’ll likely be fine, but you should install shingles over that layer as soon as possible, as long-term exposure can lead to water damage.

Crawl space encapsulation typically lasts between 10 to 20 years. If you experience a catastrophic event, like a flood, or poorly encapsulate your space with low-quality materials, it may only last a decade. Otherwise, as long as you properly maintain your crawl space, a high-quality encapsulation can last more than 20 years.

When considering finishing your basement, take into account a few pros and cons:

Pros

  • Can increase the value of your home

  • Separate space from the rest of the house 

  • Customize and personalize the basement to suit your needs and style

  • Increase the amount of living space in your home

Cons

  • May not regain enough value to cover the cost of finishing

  • Lack of natural light if it’s below ground level

  • Moisture or flooding can cause costly damage

  • Installing plumbing and electrical can be messy and costly

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.