91/100CR Score
Ranked #1 because of its Google rating and availability: 5.0★ from 128 Google reviews, open 24/7.
- 5.0★ from 128 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 290 Amity Rd, Bethany, CT 06524
Best Foundation Repair Companies in Derby, CT (2026)
171 foundation repair companies ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
The short answer
- 1
Best overall in Derby: A & A Basement Waterproofing, CR Score 91/100; 5.0★ from 128 Google reviews; open 24/7.
- 2
Best for emergencies (open 24/7): United Waterproofing, posts 24/7 hours; ranked #2 of 171.
- 6
Most-reviewed: Connecticut Basement Systems, 1,655 Google reviews at 4.8★, the most of 171 ranked; ranked #6.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
171 Derby foundation repair companies are ranked here by CR Score, from 8 published factors. 34 are open 24/7, 124 open Saturdays and 71 open Sundays, based on posted hours. The median Google rating is 4.9★ across 171 rated businesses.
Top 10 foundation repair companies in Derby at a glance
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | A & A Basement Waterproofing | 91 | 5.0★ (128) | Cheshire Village, 8 mi away | 24/7 | Overall |
| 2 | United Waterproofing | 88 | 4.9★ (86) | Ridgefield, 21 mi away | 24/7 | Emergencies |
| 3 | A DeLuca Basement Waterproofing | 86 | 4.8★ (16) | Branford, 10 mi away | 24/7 | — |
| 4 | Basement Boss | 84 | 4.9★ (34) | Bethel, 13 mi away | 24/7 | — |
| 5 | Empire Construction Waterproofing, LLC | 84 | 5.0★ (20) | Oxford, 6 mi away | Sat · Sun | — |
| 6 | Connecticut Basement Systems | 84 | 4.8★ (1,655) | Seymour, 5 mi away | — | Most reviews |
| 7 | The Builders & Cleaners | 84 | 4.9★ (120) | West Haven, 7 mi away | 24/7 | — |
| 8 | Pappy's Ultimate Construction, Drainage & Waterproofing | 83 | 5.0★ (102) | Centereach, 30 mi away | 24/7 | — |
| 9 | Full Basement Waterproofing Westchester | 82 | 5.0★ (26) | Briarcliff Manor, 40 mi away | 24/7 | — |
| 10 | Whole Basement Waterproofing Hartford CT | 82 | 5.0★ (15) | Hartford, 36 mi away | 24/7 | — |
The 171 best foundation repair companies in Derby, ranked
Ordered by CR Score, a 0–100 score from 8 published factors. Paid placement never changes the order.
Scores below: based on 6 of 8 factors; credentials and recency not yet collected. Hatched segments mark factors we don't have yet.
Based in Ridgefield, 21 mi away
88/100CR ScoreRanked #2 because of its Google rating and availability: 4.9★ from 86 Google reviews, open 24/7.
- 4.9★ from 86 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 18 Highview Rd, Ridgefield, CT 06877
Based in Branford, 10 mi away
86/100CR ScoreRanked #3 because of its Google rating and availability: 4.8★ from 16 Google reviews, open 24/7.
- 4.8★ from 16 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
Based in Bethel, 13 mi away
84/100CR ScoreRanked #4 because of its Google rating and trade focus: 4.9★ from 34 Google reviews, listed on Google as “Waterproofing service”.
- 4.9★ from 34 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
Based in Oxford, 6 mi away
84/100CR ScoreRanked #5 because of its Google rating and trade focus: 5.0★ from 20 Google reviews, listed on Google as “Waterproofing service”.
- 5.0★ from 20 Google reviews
- Hours
- Mon–Sun 9 AM–5 PM
- Address
- 11 Knorr Rd, Oxford, CT 06478
Based in Seymour, 5 mi away
84/100CR ScoreRanked #6 because of its Google rating and review volume: 4.8★ from 1,655 Google reviews, the most Google reviews on this list (1,655).
- 4.8★ from 1,655 Google reviews
- Hours
- Mon–Fri 8 AM–5 PM · Sat–Sun closed
- Address
- 33 Progress Ave, Seymour, CT 06483
Based in West Haven, 7 mi away
84/100CR ScoreRanked #7 because of its Google rating and availability: 4.9★ from 120 Google reviews, open 24/7.
- 4.9★ from 120 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 445 Front Ave Suite 191, West Haven, CT 06516
Based in Centereach, 30 mi away
83/100CR ScoreRanked #8 because of its Google rating and availability: 5.0★ from 102 Google reviews, open 24/7.
- 5.0★ from 102 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 555 Lake Ave, St James, NY 11780
Based in Briarcliff Manor, 40 mi away
82/100CR ScoreRanked #9 because of its Google rating and availability: 5.0★ from 26 Google reviews, open 24/7.
- 5.0★ from 26 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 115 Wall St, Valhalla, NY 10595
Based in Hartford, 36 mi away
82/100CR ScoreRanked #10 because of its Google rating and availability: 5.0★ from 15 Google reviews, open 24/7.
- 5.0★ from 15 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 399 Ledyard St, Hartford, CT 06114
Based in West Hills, 36 mi away
82/100CR ScoreRanked #11 because of its Google rating and trade focus: 5.0★ from 74 Google reviews, listed on Google as “Waterproofing service”.
- 5.0★ from 74 Google reviews
- Hours
- Mon–Fri 6:30 AM–5 PM · Sat–Sun 7 AM–5 PM
#12 Sp Roofing LLC
Based in Stratford, 9 mi away
82/100CR ScoreRanked #12 because of its Google rating and availability: 4.8★ from 69 Google reviews, open 24/7.
- 4.8★ from 69 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 26 Clover St, Stratford, CT 06614
Based in Danbury, 20 mi away
82/100CR ScoreRanked #13 because of its Google rating and availability: 5.0★ from 91 Google reviews, open 24/7.
- 5.0★ from 91 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 51 Sugar Hollow Rd UNIT 101, Danbury, CT 06810
#14 Groundworks
Based in North Haven, 12 mi away
82/100CR ScoreRanked #14 because of its Google rating and review volume: 4.9★ from 390 Google reviews, 390 Google reviews.
- 4.9★ from 390 Google reviews
- Hours
- Mon–Fri 7 AM–11 PM · Sat 8 AM–11 PM · Sun 10 AM–11 PM
- Address
- 101 Powdered Metal Dr, North Haven, CT 06473
Based in Rye, 39 mi away
81/100CR ScoreRanked #15 because of its Google rating and availability: 4.6★ from 29 Google reviews, open 24/7.
- 4.6★ from 29 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 222 Purchase St Suite 231, Rye, NY 10580
Based in Port Jefferson, 25 mi away
81/100CR ScoreRanked #16 because of its Google rating and availability: 5.0★ from 3 Google reviews, open 24/7.
- 5.0★ from 3 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 5 Bell Cir, Port Jefferson, NY 11777
Based in Stamford, 29 mi away
81/100CR ScoreRanked #17 because of its Google rating and availability: 5.0★ from 4 Google reviews, open 24/7.
- 5.0★ from 4 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 198 Seaton Rd APT 4, Stamford, CT 06902
Based in Hamden, 10 mi away
80/100CR ScoreRanked #18 because of its Google rating and trade focus: 5.0★ from 3 Google reviews, listed on Google as “Waterproofing service”.
- 5.0★ from 3 Google reviews
- Hours
- Mon–Sun 7 AM–7 PM
- Address
- 80 Overlook Dr, Hamden, CT 06514
#19 We Fix Cracks
Based in Stamford, 28 mi away
80/100CR ScoreRanked #19 because of its Google rating and trade focus: 4.8★ from 18 Google reviews, listed on Google as “Waterproofing service”.
- 4.8★ from 18 Google reviews
- Hours
- Mon–Sun 8 AM–6 PM
- Address
- 47 Larkin St #2a, Stamford, CT 06907
Based in Waterbury, 18 mi away
80/100CR ScoreRanked #20 because of its Google rating and trade focus: 5.0★ from 37 Google reviews, listed on Google as “Waterproofing service”.
- 5.0★ from 37 Google reviews
- Hours
- Mon–Sat 9 AM–6 PM · Sun closed
- Address
- 24 Sharon Rd, Waterbury, CT 06705
Based in Lake Carmel, 27 mi away
79/100CR ScoreRanked #21 because of its Google rating and trade focus: 4.6★ from 17 Google reviews, listed on Google as “Foundation”.
- 4.6★ from 17 Google reviews
- Hours
- Mon–Sun 7 AM–6 PM
- Address
- 2144 NY-22, Brewster, NY 10509
Based in Huntington, 35 mi away
79/100CR ScoreRanked #22 because of its Google rating and availability: 5.0★ from 3 Google reviews, open 24/7.
- 5.0★ from 3 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 5 Copperdale Ln, Huntington, NY 11743
Based in Medford, 35 mi away
79/100CR ScoreRanked #23 because of its Google rating and availability: 4.9★ from 126 Google reviews, open 24/7.
- 4.9★ from 126 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 903 Old Medford Ave, Medford, NY 11763
Based in Forest Hills, 30 mi away
79/100CR ScoreRanked #24 because of its Google rating and trade focus: 5.0★ from 13 Google reviews, listed on Google as “Waterproofing service”.
- 5.0★ from 13 Google reviews
- Hours
- Mon–Fri 7 AM–8 PM · Sat 7 AM–6 PM · Sun 7 AM–8 PM
Based in Bethel, 21 mi away
79/100CR ScoreRanked #25 because of its Google rating and trade focus: 5.0★ from 30 Google reviews, listed on Google as “Waterproofing service”.
- 5.0★ from 30 Google reviews
- Hours
- Mon–Fri 7 AM–7 PM · Sat 7 AM–3:30 PM · Sun closed
Foundation repair companies ranked #26 to #50
#1 to #25 are shown in full above. Here are #26 to #50, in CR Score order; each links to its profile. We publish the top 50 of 171 ranked foundation repair companies here; the rest are on their profiles.
Also serving Derby
20 more foundation repair companies within 40 mi that we can't rank yet: too few reviews, or a trade we couldn't confirm. Listed A to Z.
| Business | Google rating | Distance |
|---|---|---|
| ACP HOME IMPROVEMENTLLC | 5.0★ (1) | In Derby |
| AM Basement Solutions | 5.0★ (2) | 21 mi |
| American Dry Basement Systems | 5.0★ (2) | 33 mi |
| American Dry Basement Systems | 5.0★ (1) | 10 mi |
| American Dry Basement Systems LLC | 5.0★ (2) | 19 mi |
| C-Rod Foundations LLC | 5.0★ (2) | 20 mi |
| Doss Foundations | 5.0★ (1) | 6 mi |
| Eagle Basement Waterproofing | 5.0★ (2) | 27 mi |
| Ever Build Masonry and Waterproofing | 5.0★ (2) | 31 mi |
| JABRY'S ROOFING | 5.0★ (2) | 35 mi |
| LJM Foundations & Masonry, LLC | 5.0★ (2) | 21 mi |
| Maintenance Experts of Long Island | 3.0★ (2) | 35 mi |
| Marini and Son Masonry LLC | In Derby | |
| New Haven Roofing LLC | 5.0★ (1) | In Derby |
| Norwalk Marine Contractors Inc | 5.0★ (1) | 11 mi |
| Quality Masonry And Foundation Repair | 5.0★ (2) | 11 mi |
| Rain King Waterproofing | 3.5★ (2) | 33 mi |
| Rain King Waterproofing, Inc. | 5.0★ (2) | 18 mi |
| Sweet Mold Removal Restoration | 5.0★ (2) | 30 mi |
| ValueDry Basement Waterproofing & Remodeling | 4.0★ (2) | 11 mi |
How much do foundation repair companies cost in Derby?
National price ranges in USD, not adjusted for Derby. Each row names its basis and the month we checked it.
| Job | Low | Typical | High | Basis | Checked |
|---|---|---|---|---|---|
| Foundation repair | $2,225 | $5,174 | $8,133 | Per project: typical range of customer-reported repairs. US national range | October 2026 |
How we ranked Derby foundation repair companies
We scored 171 Derby foundation repair companies on 8 factors, weighted as shown. A business is ranked when its trade is confirmed and it has 3 or more Google reviews or a claimed profile. Unknown factors are left out of the score, not counted as zero. Scores last refreshed October 22, 2026.
Paid placement never changes a rank or score. Featured businesses are paid, labelled, limited to 3 and shown above the ranking, outside it.
| Factor | Weight | Computed from | In Derby data |
|---|---|---|---|
| Reputation | 35% | Bayesian-adjusted Google star rating | Measured |
| Credentials | 15% | Active state license 0.6, bond 0.2, workers’ comp 0.2 | Not yet collected |
| Review volume | 10% | log10(reviews + 1) against the list maximum | Measured |
| Recency | 10% | Share of reviews from the last 12 months | Not yet collected |
| Availability | 10% | Weekly open hours, Saturday, Sunday, 24/7 or same-day | Measured |
| Trade focus | 10% | Google main category 1.0, business name 0.7, additional category 0.5 | Measured |
| Proximity | 5% | 1.0 when based in the city, falling to 0 at the trade’s radius | Measured |
| Completeness | 5% | Website, photos, description, hours, claimed profile (0.2 each) | Measured |
Foundation repair companies in Derby: frequently asked questions
Who is the best foundation repair company in Derby?
By CR Score, the highest-ranked foundation repair company in Derby, CT is A & A Basement Waterproofing with a CR Score of 91/100. It has 5.0★ from 128 Google reviews. It is open 24/7. United Waterproofing (#2) and A DeLuca Basement Waterproofing (#3) follow. We ranked 171 foundation repair companies on 8 factors, last updated October 22, 2026.
How many foundation repair companies are there in Derby?
ContractorsRanked ranks 171 foundation repair companies serving Derby, CT. Another 20 within 40 mi are listed but not ranked yet. Counts are as of October 2026.
Which foundation repair companies in Derby are open 24/7?
34 ranked foundation repair companies in Derby post 24/7 hours. The highest-ranked are A & A Basement Waterproofing (#1), United Waterproofing (#2) and A DeLuca Basement Waterproofing (#3). Hours come from each business's Google listing as of October 2026, so call to confirm.
Which foundation repair companies in Derby work on weekends?
124 of 171 ranked foundation repair companies post Saturday hours and 71 post Sunday hours. The highest-ranked open Saturdays are A & A Basement Waterproofing (#1), United Waterproofing (#2) and A DeLuca Basement Waterproofing (#3). Posted hours are office hours; crews may book weekend jobs separately.
How much does foundation repair cost in Derby?
Foundation repair typically costs $2,225 to $8,133, with $5,174 typical (Per project: typical range of customer-reported repairs. US national range). This is a national range, not adjusted for Derby. Prices were last checked October 2026. Get at least two written quotes before you hire.
What Google rating do Derby foundation repair companies have?
The median Google rating among 171 rated foundation repair companies in Derby is 4.9★, with a median of 18 reviews. Connecticut Basement Systems has the most, 1,655 reviews, and ranks #6. We adjust ratings for review count, so a few five-star reviews cannot top the list.
How does ContractorsRanked rank foundation repair companies?
Each foundation repair company gets a 0–100 CR Score from 8 published factors, led by reputation (35%), credentials (15%), review volume (10%) and recency (10%). Factors we cannot measure are left out, not scored as zero. Only businesses with a confirmed trade and 3 or more reviews, or a claimed profile, are ranked.
Do foundation repair companies outside Derby count in this ranking?
Yes, if they are within 40 mi of the Derby city center, our service radius for foundation repair companies. Each listing shows where the business is based and how far away it is. Proximity is 5% of the CR Score, so a nearby business gets a small edge.
Update log for Derby
- October 2026: CR Scores recalculated for 171 foundation repair companies serving Derby.
- October 2026: 1 duplicate listing merged.
More foundation repair companies and Derby pages
Foundation repair companies near Derby
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