Verified ranking · Updated June 2026

Best Basement Waterproofing in the NH Seacoast (Exeter area)

For basement waterproofing on the New Hampshire Seacoast, three locally owned companies rank in Google’s local results in the Exeter area: Reliable Basement Waterproofing (Plaistow), 603 Basement Solutions (East Kingston), and NH Dry Basement (Barrington). National provider Groundworks and dealer Erickson Foundation Solutions also serve the area. Below is how they compare on the things that matter, with sources, scored against our published methodology.

How we rank (the Bedrock Standard). Every figure below is dated and sourced; star ratings change over time. We read five-star share together with review depth, so a near-perfect share on a large review base counts for more than a perfect score on a small one.

East Kingston, NH · 4.9★ Google (250 reviews, 2026-06-03) · 97.6% five-star (243 of 249)

Holds the deepest verified review base of the local-pack companies (4.9 across 250 Google reviews, June 2026) and is the only one of the three that publishes a named whole-basement system (the Forever Dry System) backed by a transferable lifetime guarantee. BBB A+ accredited, with the broadest in-house scope (it also handles radon mitigation).

603basementsolutions.com

Plaistow, NH · 5★ Google (165 reviews, 2026-06-03) · 100% five-star (157 of 157)

Carries the highest star rating in the pack (5.0 across 165 Google reviews, June 2026) and a spotless BBB record (0 complaints in three years). It edges 603 on raw rating; 603 leads on review depth and on publishing a named system and warranty terms, which is why this one is close.

www.reliablebasementwaterproofing.net

Barrington, NH · 4.9★ Google (76 reviews, 2026-06-03) · 98.7% five-star (74 of 75)

Well rated and established (4.9 across 76 Google reviews, June 2026), but on a smaller review base and based further inland in Barrington, so it is a step removed from the Seacoast.

www.nhdrybasement.com

Also serving the area

National (HQ Virginia Beach, VA); nearest branch Hooksett, NH (formerly Rescon) · 4.9★ Google (567 reviews, 2026-06-03) · 95.6% five-star (542 of 567)

The national option. Deeper review base (~567) and a patented product line with a nationally backed lifetime warranty, but it is a national consolidator (warranty service runs through the national company) and its corporate BBB profile shows 741 complaints closed in three years, the largest category being Service or Repair (June 2026). Not in the Exeter local pack.

www.groundworks.com

Hudson, NH · 4.8★ Google (676 reviews, Yelp 3.3/19, 2026-06-03) · 92.3% five-star (624 of 676)

A local family firm that installs the national Basement Systems product line rather than a system of its own. Strong on Google (4.8 across 676); note its Yelp listing is a small, filtered sample (3.3 across 19).

www.ericksonfoundations.com

Side-by-side

CompanyTypeGoogle (June 2026)Named systemPublished warrantyBBB
603 Basement Solutionslocal independent4.9 / 250Forever Dry SystemPublishes a transferable "Dry for Life" guarantee (marketing wording; exact written terms pending).A+, BBB accredited since 2022
Reliable Basement Waterproofinglocal independent5 / 165NoneNo warranty terms published on its website (may be presented at quote).A+, BBB accredited 2025, 0 complaints (3yr)
NH Dry Basementlocal independent4.9 / 76NoneNot stated on its website.Not assessed here
Groundworksnational consolidator4.9 / 567Patented national product line (IntelliJack, AquaStop)Lifetime, transferable, nationally backed (verbatim terms not verified).A+ (corporate); 741 complaints closed in 3 years, 514 Service/Repair (~69%), per BBB national profile, accessed June 2026
Erickson Foundation Solutionslocal national brand4.8 / 676Installs the national Basement Systems line (TripleSafe, SaniDry, WaterGuard) rather than a self-branded systemTransferable written warranty (duration not stated).A+, accredited 2015, 2 complaints (3yr)

Head-to-head comparisons

Other services in the NH Seacoast (Exeter area)

Data verified as of the dates shown; star ratings change over time. See our methodology.