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Best basement waterproofing pros near Sunapee, NH

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Top-Rated Basement waterproofing pros in Sunapee - 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 Sunapee, 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 Groundworks
Groundworks
4.6(
26
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Sunapee, 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
182 neighbors recently requested a quote
Recommended by56%of homeowners
Avatar for Quantum Contracting, LLC
Quantum Contracting, LLC
4.3(
38
)
Basement Drainage Channels - Install

Serving Sunapee, NH and surrounding areas

Approved

In business since 2015

Free estimates

Credit card accepted

"Quantum Contracting is great! Tyler and Austin are very professional and hard workers. Very efficient and my porch looks fantastic. I would hire them again in a flash and they are very honest and fair and really know what they are doing."
Small Garden
Complete Landscape Renovation
Grade Work
Brick Pathway
Small Retaining Wall

+23

Response time2 days
Response rate89%
10 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 Sunapee, 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 Sunapee, 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
Avatar for Green Mountain Basement Solutions LLC
Green Mountain Basement Solutions LLC
4.0(
30
)
Basement Drainage Channels - InstallBasement Drainage Channels - RepairFoundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Sunapee, NH and surrounding areas

In business since 2007

Free estimates

Emergency services offered

"The work itself, the actual basement waterproofing appears to be working but our flood season hasn't come yet so, I'm reserving judgement. But, the way the work was done was a problem and the initial way that they got with the problem wasn't satisfactory. Eventually, months after work I did get some resolution but is wasn't a smooth transaction. We moved some of the finished portions of the basement to do their work and the way that that was handled was very sloppy and rushed, and very expensive to repair. And then, when the initial point of having somebody come and look at all my questions, it was not the owner, it was his foreman and it was not dealt within a professional manner. After 2 contacts, tried to explain what the problems were and has offered that they have an annual service to make sure that everything is working and there's a fee for that, though he offered 2 years of that with no cost, so that was a nice gesture. He tried to make up for the problems but like I said, there were problems."
Recommended by75%of homeowners
Showing 1-10 of 42
Basement Waterproofing FAQs, answered by experts

You can seal a concrete slab by cleaning the surface, filling in any cracks, etching the surface, applying a sealer, and letting it dry. Concrete slabs don't typically need sealing, but you can use a topical concrete sealer if you notice signs of water damage. If you haven't already fixed the cause of the leak, then you'll want to repair the plumbing before you seal a concrete slab.

Encapsulation can take the place of crawl space vents since it protects the area from moisture and air all year round. Determining whether you should open or close crawl space vents can be complicated since it often depends on the weather and humidity. Skip this step by investing in crawl space encapsulation whenever possible.

If you set up a dehumidifier, it will usually dry out your wet crawl space within 12 to 24 hours. Once the space is dry, it’s a good idea to take preventative measures to keep it dry. These include installing a French drain or other exterior foundation drainage system, installing a sump pump in the crawl space, and installing a vapor barrier in addition to leaving the dehumidifier running.

Many prevention methods can be used individually or in combination to waterproof your basement. Some of the most common waterproofing methods include:

  • Using dehumidifiers 

  • Silicate concrete sealers

  • Vapor barriers 

  • Baseboard channels 

  • Drain tile systems

  • Waterproofing paint

  • Drainage systems

  • Epoxy injection

  • Interior French drains

  • Exterior excavation and waterproofing

  • Cement waterproofing

  • Weep tiles

  • Liquid membrane

  • Sheet membrane 

  • Yard grading

  • Gutters and downspouts

The most expensive foundation repair method is to install helical piers. Helical piers are a type of steel pier used to support sinking foundations in areas with poor soil conditions or deep bedrock. This foundation repair method can cost up to $3,000 per pier, including labor, because of its material and labor-intensive installation process. Total foundation repair costs can easily reach over $20,000 using this method.

The Sunapee, NH homeowners’ guide to basement waterproofing services

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