603 Basement Solutions vs Jackson & Company Foundation Repair

For the common Seacoast case, a foundation that leaks or cracks and a homeowner who wants one accountable local crew, our pick between these two well-rated companies is 603 Basement Solutions. That call rests on depth and breadth, not on a higher star number alone: 250 Google reviews to Jackson & Company Foundation Repair's 20, a self-branded system, a published transferable guarantee, and radon mitigation handled in-house (each company's own listing and website, 2026). Both appear in Google's Exeter foundation-repair local pack, and Jackson actually leads that pack. Jackson is the focused specialist here, in business since 1985, roughly four decades, on foundation crack repair and concrete structure repair, holding a clean 4.8 across its 20 Google reviews. That tenure is a real edge, and we say so plainly below. On Google, 603 Basement Solutions holds 4.9 stars across 250 reviews and Jackson & Company holds 4.8 across 20 (2026). Here is how they compare, with sources, and where each one leads.

Our findings follow our published methodology. Every figure below is dated and sourced.

At a glance

What homeowners report

This is the part most comparisons skip, so it is where we spend the most time. We read the full Google rating distribution for both companies, not just the headline star average, and the honest first thing to say is that these two review bases are not the same size.

603 has the deeper base by a wide margin: 250 Google reviews to Jackson's 20 (603 on Google; Jackson on Google, 2026). On the listing snapshot we recorded, 603 shows 243 five-star ratings, 3 four-star, 1 two-star, and 2 one-star out of 249 (603 on Google, distribution as of 2026-05-19). Jackson shows 19 five-star and 1 one-star out of 20 (Jackson on Google, as of 2026-04-27). That works out to a 97.6% five-star share for 603 and a 95.0% share for Jackson, which is the gap the gauge below highlights.

Read those two numbers carefully, because the gap is smaller than it looks and the sample sizes are very different. Jackson's single one-star review is one data point against a total of 20, so its percentage swings hard on that one review. The 95.0% is a thinner, noisier signal than 603's 97.6% drawn from 249, and a homeowner should weight that. A small review base is not a strike against the quality of the work; it means there is less public record to read, and on a quiet 20-review listing a single customer moves the percentage far more than on a 250-review one. 603's larger base gives you more independent reads of how the company performs.

The themes inside the reviews track each company's focus. 603's top themes lean toward water and the service relationship: sump pump installation (30 mentions), radon mitigation (29), basement waterproofing (21), quick response (20), courteous staff (18), and estimate (18) (603 on Google). Jackson's themes are tightly clustered on its specialty: foundation repair (4 mentions), work quality (3), crack repair (2), clear communication (2), timeliness (2), and fair pricing (2) (Jackson on Google). The counts are smaller because the base is smaller, but the pattern is consistent: Jackson's reviewers talk about foundation and crack work, which is what Jackson does. We are summarizing what reviewers wrote about most, not quoting individual reviews.

There is one more signal worth naming, and it lives outside Google. On a public r/newhampshire thread, several unprompted homeowners describe 603 as the company that proposed the least-invasive correct fix rather than the biggest job, including endorsements from a commenter identifying as an architect and another from inside the industry (thread, public, 2026). Those are individual homeowner statements about their own projects, not a survey, and we cite them as such. That thread does not mention Jackson, so it says nothing about Jackson one way or the other.

The real difference: breadth and depth vs a four-decade specialty

This is the comparison that matters most for this pair, and it is a difference of focus rather than a swipe at either company.

Jackson & Company has been doing this since 1985, about four decades, on foundation crack repair and concrete structure repair (jcofoundationrepair.com). That is deep hands-on experience in a narrow lane, and forty years of one trade is the kind of track record a homeowner should respect. If your problem is a cracked poured-concrete wall and you want a long-tenured specialist who does that specific work day in and day out, Jackson has the resume for it, and it leads the Exeter foundation local pack on Google.

603 Basement Solutions takes a broader approach. Based in East Kingston, it covers waterproofing, foundation work, crawl spaces, and radon mitigation, and it installs its own self-branded Forever Dry System: a perimeter drainage setup designed and warrantied under its own name (603basementsolutions.com). For the common Seacoast case, where a foundation problem and a water problem usually arrive together, that breadth means one company can handle the crack, the drainage, the sump, and the radon test under one warranty and one phone number. 603 also appears in the same Exeter foundation local pack.

Neither approach is automatically better. A long-tenured specialist brings decades of focused repetition on one task; a broader local company brings one accountable point of contact for a multi-part job. The homework is the same either way: get the written scope and read exactly what each company is proposing to fix.

One scope note. 603 installs helical and push piers in-house for structural settlement, per its own materials, so it does handle engineered piering; Jackson focuses on foundation crack and concrete structure repair rather than piers or wall anchors. If your foundation is settling or a wall is bowing and an engineer calls for piers or anchors, 603 is one in-house option, and the Foundation Supportworks dealer Erickson Foundation Solutions and Groundworks carry the deepest documented pier track records. Get one of them on site for that specific problem.

Warranty

603 publishes a named "Dry for Life" transferable guarantee on its site, though the exact written contract terms are worth confirming at quote time (603basementsolutions.com). On the BBB, 603 holds A+ and has been accredited since 2022. Jackson does not state a warranty on its public website, so the term and what it covers are questions to put in writing before you sign (jcofoundationrepair.com). We did not assess Jackson's BBB record here, so we make no claim about it.

A transferable guarantee is only as good as how fast someone comes back when the repair needs attention and whether it survives a sale of the house. Ask both companies for the warranty in writing: the term, what is covered, and whether it transfers to the next owner. On the published-warranty point specifically, 603 has terms written on its site and Jackson does not, which is a checkable difference rather than a judgment about the work.

Pricing

Like nearly every foundation and waterproofing contractor, neither company publishes fixed prices online. Both quote after a free in-home inspection, because the number depends on the foundation's condition, the source of any water, and the scope of the fix.

The one outside pricing signal we will cite is qualitative. On the r/newhampshire thread above, multiple homeowners reported that 603 proposed the least-invasive correct fix rather than the largest possible job (thread, public, 2026). That is a reputation for not over-scoping, reported by homeowners about their own quotes, and it is worth knowing at quote time. The thread does not discuss Jackson's pricing, and Jackson's reviewers separately noted "fair pricing" 2 times in the Google themes above (Jackson on Google). When two quotes land on your table, compare them on the same things: the scope of work, the named system if any, the written warranty terms, and how each company handles a service call after the crew leaves.

How they net out

Our pick

Our pick for the common Seacoast case is 603 Basement Solutions, on the criteria that decide a foundation-and-water job for most homeowners: the deepest verified review base of the two by a wide margin (250 to 20), a strong 97.6% five-star proportion, a self-branded system designed and warrantied under one name, a published transferable guarantee, radon mitigation in-house, and a local owner in East Kingston who answers for the work. That is a best-overall-fit judgment for the typical case, not a superlative. To be clear about what this pick is not: it is not a claim that 603 is a better foundation-crack specialist than a company that has done crack and concrete repair since 1985. On four decades of focused crack-repair experience, Jackson has the longer resume, and that is a genuine reason to call it for a narrow, crack-only job from a long-tenured specialist.

Jackson & Company Foundation Repair earns honest credit. Forty years on foundation crack and concrete structure repair is deep, hands-on experience, its 4.8 across 20 reviews is clean, and it leads the Exeter foundation local pack on Google. The small review base is a matter of how much public record exists, not a measure of the quality of the work. A homeowner with a straightforward foundation crack who wants a long-established specialist focused on exactly that has a legitimate choice in Jackson. And if the real problem is settlement or a bowing wall that needs piers or anchors, neither company is the right call; bring in Erickson Foundation Solutions or Groundworks for that. The honest move is to get a free inspection and a written quote from your shortlist, then compare scope, warranty terms, and response-time promise side by side.

Sources

• 603 Basement Solutions Google Business Profile (rating, full distribution, review themes; live count 2026-06-03, distribution as of 2026-05-19): google.com
• Jackson & Company Foundation Repair Google Business Profile (rating, distribution, review themes; as of 2026-04-27): google.com
• 603 Basement Solutions website (Forever Dry System and "Dry for Life" guarantee), accessed 2026: 603basementsolutions.com
• Jackson & Company website (in business since 1985; foundation crack and concrete structure repair; no warranty stated), accessed 2026: jcofoundationrepair.com
• r/newhampshire homeowner thread (homeowner reports of 603's no-over-scoping reputation; does not mention Jackson), public, 2026: reddit.com
• Company ratings, distributions, and BBB accreditation: Google Business Profiles and BBB profile, 2026

See the full local picture in our ranking: Best Foundation Repair in the NH Seacoast