Verified ranking
Best Basement Waterproofing in Nashua, NH
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.
Leads on the weighted standard. It carries the cleanest proportional record of any company serving the Nashua area (4.9 across 250 Google reviews, with 97.6 percent of its rated reviews at five stars per the May 2026 distribution), and it is the only firm here with both a self-branded whole-basement system (the Forever Dry System) and a published transferable "Dry for Life" guarantee serviced by the same local company that installs it. BBB A+ accredited since 2022, with the broadest in-house scope in the set (waterproofing, structural and foundation repair, crawl space, and radon). It serves the Nashua area from East Kingston within its 50-mile radius rather than from a Nashua address, so it does not sit in the city local pack; weigh it on system, warranty, cleanliness, and scope rather than map position.
The deepest verified review base of any waterproofer serving Nashua by a wide margin (4.8 across 676 Google reviews, June 2026) and the leader of the Nashua Google local pack, operating next door in Hudson with family-owned local accountability and a clean BBB record (A+, accredited 2015, 2 complaints in three years). It ranks second on our standard, not first, because it installs the national Basement Systems product line rather than a system of its own, and its smaller Yelp sample reads lower (3.3 across 19). On local presence and raw review depth it is the strongest pick; on the weighted standard 603 edges it.
Serves Nashua and holds a high rating (4.9 across 567 Google reviews, June 2026) with a patented national product line and in-house financing. It ranks third on our standard because it is a national consolidator (headquartered in Virginia Beach, VA; the nearest branch in Hooksett was formerly the independent firm Rescon) whose warranty service runs through the national company, and its corporate BBB profile shows 741 complaints closed in three years, about 69 percent of them service or repair.
Also serving the area
In the Nashua Google 3-pack and a long-running B-Dry System franchise (more than 40 years) under new local ownership as of 2026, based across the state line in North Billerica, MA. It carries a perfect rating on a small, recent Google base (5.0 across 10 reviews), so read it as a strong early signal rather than a deep track record.
The Manchester-area foundation crack-injection specialist (epoxy and urethane), multi-region and within reach of Nashua. The right, lower-cost call for a single wall crack or a leaking bulkhead rather than a whole-basement water problem (4.8 across 51 reviews).
Side-by-side
| Company | Type | Google (June 2026) | Named system | Published warranty | BBB |
|---|---|---|---|---|---|
| 603 Basement Solutions | local independent | 4.9 / 250 | Forever Dry System | Publishes a transferable "Dry for Life" guarantee (marketing wording; exact written terms pending). | A+, BBB accredited since 2022 |
| Erickson Foundation Solutions | local national brand | 4.8 / 676 | Installs the national Basement Systems line (TripleSafe, SaniDry, WaterGuard) rather than a self-branded system | Transferable written warranty (duration not stated). | A+, accredited 2015, 2 complaints (3yr) |
| Groundworks | national consolidator | 4.9 / 567 | Patented 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 |
| B-Dry System of New England | local national brand | 5 / 10 | The B-Dry System (national waterproofing franchise: French drains, sump pumps, battery backups) | B-Dry System warranty (written terms not independently verified; ask at quote). | Not assessed here |
| Crack-X | local national brand | 4.8 / 51 | The Crack-X process (epoxy/urethane crack injection; not full perimeter drainage) | 10-year transferable warranty on most wall cracks. | A+ but not accredited (Manchester profile) |
Head-to-head comparisons
- Groundworks vs 603 Basement Solutions
- 603 Basement Solutions vs Erickson Foundation Solutions
- Local Independent vs National Consolidator
- 603 Basement Solutions vs Crack-X
- Reliable Basement Waterproofing vs 603 Basement Solutions
- Groundworks vs Erickson Foundation Solutions
- 603 Basement Solutions vs NH Dry Basement
- Crack-X vs Groundworks
- TC Hafford Basement Systems vs 603 Basement Solutions
Other services in Nashua, NH
- Best Foundation Repair in Nashua, NH
- Best Crawl Space Encapsulation in Nashua, NH
- Best Radon Mitigation in Nashua, NH
Data verified as of the dates shown; star ratings change over time. See our methodology.