91/100CR Score
Ranked #1 because of its Google rating and availability: 4.8★ from 634 Google reviews, open 24/7.
- 4.8★ from 634 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 129 Lytton Blvd, Toronto, ON M4R 1L5
Best Foundation Repair Companies in Ajax, ON (2026)
298 foundation repair companies ranked by CR ScoreUpdated 0 paid placements in this rankingHow we rank →
The short answer
- 1
Best overall in Ajax: RCC Waterproofing Toronto, CR Score 91/100; 4.8★ from 634 Google reviews; open 24/7.
- 3
Best for emergencies (open 24/7): ACCL Basement Wateproofing, posts 24/7 hours; ranked #3 of 298.
- 2
Most-reviewed: Groundworks, 1,412 Google reviews at 4.9★, the most of 298 ranked; ranked #2.
Rankings can't be bought. Contractors can't pay to change their rank or score. How we rank
298 Ajax foundation repair companies are ranked here by CR Score, from 8 published factors. 119 are open 24/7, 246 open Saturdays and 184 open Sundays, based on posted hours. The median Google rating is 5.0★ across 298 rated businesses.
Top 10 foundation repair companies in Ajax at a glance
| Rank | Business | CR Score | Google rating | Based in | Hours | Best for |
|---|---|---|---|---|---|---|
| 1 | RCC Waterproofing Toronto | 91 | 4.8★ (634) | Toronto, 34 km away | 24/7 | Overall |
| 2 | Groundworks | 91 | 4.9★ (1,412) | East Gwillimbury, 24 km away | Sat · Sun · Evenings | Most reviews |
| 3 | ACCL Basement Wateproofing | 89 | 5.0★ (29) | Ajax | 24/7 | Emergencies |
| 4 | Aquatech Basement Waterproofing Toronto | 88 | 5.0★ (655) | Toronto, 40 km away | Sat · Sun · Evenings | — |
| 5 | RCC Waterproofing Vaughan | 88 | 4.9★ (180) | Concord, 45 km away | 24/7 | — |
| 6 | Aquatech Waterproofing | 87 | 5.0★ (78) | Vaughan, 43 km away | 24/7 | — |
| 7 | Lympia Contracting Inc | 87 | 5.0★ (30) | Richmond Hill, 25 km away | 24/7 | — |
| 8 | RCC Waterproofing Markham | 87 | 5.0★ (32) | Markham, 27 km away | 24/7 | — |
| 9 | RCC Waterproofing North York | 87 | 4.9★ (77) | Toronto, 41 km away | 24/7 | — |
| 10 | Jetflo Drain & Waterproofing | 87 | 4.9★ (70) | Ajax | 24/7 | — |
The 298 best foundation repair companies in Ajax, 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.
#2 Groundworks
Based in East Gwillimbury, 24 km away
91/100CR ScoreRanked #2 because of its Google rating and trade focus: 4.9★ from 1,412 Google reviews, listed on Google as “Waterproofing service”.
- 4.9★ from 1,412 Google reviews
- Hours
- Mon–Fri 7 AM–11 PM · Sat 8 AM–11 PM · Sun 10 AM–11 PM
- Address
- 12029 McCowan Rd, Whitchurch-Stouffville, ON L4A 7X5
Based in Ajax
89/100CR ScoreRanked #3 because of its Google rating and availability: 5.0★ from 29 Google reviews, open 24/7.
- 5.0★ from 29 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
Based in Toronto, 40 km away
88/100CR ScoreRanked #4 because of its Google rating and trade focus: 5.0★ from 655 Google reviews, listed on Google as “Waterproofing service”.
- 5.0★ from 655 Google reviews
- Hours
- Mon–Sun 7 AM–12 AM
- Address
- 20 Hyde Ave, Toronto, ON M6M 1J3
Based in Concord, 45 km away
88/100CR ScoreRanked #5 because of its Google rating and availability: 4.9★ from 180 Google reviews, open 24/7.
- 4.9★ from 180 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 7140 Islington Ave, Woodbridge, ON L4L 1V9
Based in Vaughan, 43 km away
87/100CR ScoreRanked #6 because of its Google rating and availability: 5.0★ from 78 Google reviews, open 24/7.
- 5.0★ from 78 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 15 Galloway Dr, Vaughan, ON L4L 7J4
Based in Richmond Hill, 25 km away
87/100CR ScoreRanked #7 because of its Google rating and availability: 5.0★ from 30 Google reviews, open 24/7.
- 5.0★ from 30 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
Based in Markham, 27 km away
87/100CR ScoreRanked #8 because of its Google rating and availability: 5.0★ from 32 Google reviews, open 24/7.
- 5.0★ from 32 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 15 Allstate Pkwy 6th Floor, Markham, ON L3R 5B4
Based in Toronto, 41 km away
87/100CR ScoreRanked #9 because of its Google rating and availability: 4.9★ from 77 Google reviews, open 24/7.
- 4.9★ from 77 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 4101 Steeles Ave W, Toronto, ON M3N 2H4
Based in Ajax
87/100CR ScoreRanked #10 because of its Google rating and availability: 4.9★ from 70 Google reviews, open 24/7.
- 4.9★ from 70 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
#11 ROOTERWORX
Based in Mississauga, 56 km away
87/100CR ScoreRanked #11 because of its Google rating and availability: 5.0★ from 121 Google reviews, open 24/7.
- 5.0★ from 121 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 34 Queen St W unit 4, Mississauga, ON L5H 1L4
Based in Toronto, 37 km away
87/100CR ScoreRanked #12 because of its Google rating and availability: 5.0★ from 51 Google reviews, open 24/7.
- 5.0★ from 51 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 545 King St W, Toronto, ON M5V 1M1
Based in Mississauga, 55 km away
87/100CR ScoreRanked #13 because of its Google rating and availability: 5.0★ from 109 Google reviews, open 24/7.
- 5.0★ from 109 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 155 Oakes Dr, Mississauga, ON L5G 3M2
Based in Toronto, 38 km away
87/100CR ScoreRanked #14 because of its Google rating and availability: 5.0★ from 51 Google reviews, open 24/7.
- 5.0★ from 51 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 1015 Bloor St W, Toronto, ON M6H 1M1
Based in Mississauga, 58 km away
86/100CR ScoreRanked #15 because of its Google rating and availability: 5.0★ from 123 Google reviews, open 24/7.
- 5.0★ from 123 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 1247 Cloverbrae Crescent, Mississauga, ON L5H 2Z6
Based in North York, 41 km away
86/100CR ScoreRanked #16 because of its Google rating and availability: 4.8★ from 97 Google reviews, open 24/7.
- 4.8★ from 97 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 168A Oakdale Rd Unit 7, North York, ON M3N 1V9
Based in Oshawa, 9 km away
86/100CR ScoreRanked #17 because of its Google rating and trade focus: 5.0★ from 49 Google reviews, listed on Google as “Waterproofing service”.
- 5.0★ from 49 Google reviews
- Hours
- Mon–Sun 7 AM–7 PM
Based in Oshawa, 16 km away
86/100CR ScoreRanked #18 because of its Google rating and availability: 4.8★ from 182 Google reviews, open 24/7.
- 4.8★ from 182 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 712 Wilson Rd S, Oshawa, ON L1H 6E7
Based in Toronto, 37 km away
86/100CR ScoreRanked #19 because of its Google rating and trade focus: 4.9★ from 274 Google reviews, listed on Google as “Waterproofing service”.
- 4.9★ from 274 Google reviews
- Hours
- Mon–Sun 8 AM–8 PM
- Address
- 371 Front St W Suite # 247, Toronto, ON M5V 3S8
Based in Mississauga, 56 km away
86/100CR ScoreRanked #20 because of its Google rating and availability: 4.9★ from 121 Google reviews, open 24/7.
- 4.9★ from 121 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 90 Burnhamthorpe Rd W #1400, Mississauga, ON L5B 0H9
Based in Toronto, 48 km away
86/100CR ScoreRanked #21 because of its Google rating and trade focus: 5.0★ from 271 Google reviews, listed on Google as “Waterproofing service”.
- 5.0★ from 271 Google reviews
- Hours
- Mon–Fri 8 AM–9 PM · Sat 8 AM–7 PM · Sun 8 AM–8 PM
- Address
- 4 Faversham Crescent, Toronto, ON M9C 3X4
Based in Etobicoke, 46 km away
86/100CR ScoreRanked #22 because of its Google rating and availability: 5.0★ from 50 Google reviews, open 24/7.
- 5.0★ from 50 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 41 Advance Rd Suite 200, Etobicoke, ON M8Z 2S6
Based in Mississauga, 54 km away
86/100CR ScoreRanked #23 because of its Google rating and availability: 5.0★ from 70 Google reviews, open 24/7.
- 5.0★ from 70 Google reviews
- Open 24/7
- Hours
- Open 24 hours, 7 days
- Address
- 1251-A Kamato Rd, Mississauga, ON L4W 2M2
Based in Cobourg, 29 km away
86/100CR ScoreRanked #24 because of its Google rating and trade focus: 5.0★ from 102 Google reviews, listed on Google as “Foundation”.
- 5.0★ from 102 Google reviews
- Hours
- Mon–Fri 9 AM–9 PM · Sat–Sun 10 AM–4 PM
- Address
- Bowmanville, ON L1C 5C9
#25 City Wide Group
Based in East York, 28 km away
86/100CR ScoreRanked #25 because of its Google rating and trade focus: 4.8★ from 177 Google reviews, listed on Google as “Waterproofing service”.
- 4.8★ from 177 Google reviews
- Hours
- Mon–Sat 8 AM–8 PM · Sun 9 AM–3 PM
- Address
- 25 Hollinger Rd #3, East York, ON M4B 3N4
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 298 ranked foundation repair companies here; the rest are on their profiles.
Also serving Ajax
20 more foundation repair companies within 64 km that we can't rank yet: too few reviews, or a trade we couldn't confirm. Listed A to Z.
| Business | Google rating | Distance |
|---|---|---|
| Apex Builds | 4.4★ (27) | In Ajax |
| ASG Construction & Restoration | 4.3★ (6) | In Ajax |
| ATI Masonry | 5.0★ (4) | In Ajax |
| AZAD Landscaping & Interlocking | 4.4★ (36) | In Ajax |
| Clayson Construction | 5.0★ (3) | In Ajax |
| Concrete Warrior Inc. | 4.9★ (36) | In Ajax |
| Esra Landscaping & Reno | 5.0★ (13) | In Ajax |
| Everest Drain & Plumbing: Whitby's Local Plumber | 5.0★ (5) | In Ajax |
| House of Quayson | 5.0★ (14) | In Ajax |
| Jarvis Contracting Inc. | 5.0★ (24) | In Ajax |
| Laptiva | 4.4★ (12) | In Ajax |
| Limestone Construction and Excavating | 5.0★ (26) | In Ajax |
| MaKenady Construction Services Inc. General Contractor Ajax | 5.0★ (10) | In Ajax |
| My Basement Leaks | 4.8★ (4) | In Ajax |
| Ollivierre Contracting | 5.0★ (12) | In Ajax |
| Phillips Contracting & Renovation | 4.9★ (9) | In Ajax |
| Reliable Renos | 5.0★ (10) | In Ajax |
| Rock Stone Masonry | 4.9★ (54) | In Ajax |
| Samar Masonry Construction Pickering , Ajax & Whitby | 5.0★ (7) | In Ajax |
| Touch of Class Group Ltd. | 5.0★ (10) | In Ajax |
How much do foundation repair companies cost in Ajax?
US national ranges converted to CAD, not adjusted for Ajax. Each row names its basis and the month we checked it.
| Job | Low | Typical | High | Basis | Checked |
|---|---|---|---|---|---|
| Foundation repair | CA$3,130 | CA$7,270 | CA$11,430 | Per project: typical range of customer-reported repairs. US national range converted at 1.4054 CAD per USD (Bank of Canada, October 20, 2026) | October 2026 |
How we ranked Ajax foundation repair companies
We scored 298 Ajax 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 Ajax 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 Ajax: frequently asked questions
Who is the best foundation repair company in Ajax?
By CR Score, the highest-ranked foundation repair company in Ajax, ON is RCC Waterproofing Toronto with a CR Score of 91/100. It has 4.8★ from 634 Google reviews. It is open 24/7. Groundworks (#2) and ACCL Basement Wateproofing (#3) follow. We ranked 298 foundation repair companies on 8 factors, last updated October 22, 2026.
How many foundation repair companies are there in Ajax?
ContractorsRanked ranks 298 foundation repair companies serving Ajax, ON. 7 of them are based in Ajax; the rest serve it from nearby towns. Another 20 within 64 km are listed but not ranked yet. Counts are as of October 2026.
Which foundation repair companies in Ajax are open 24/7?
119 ranked foundation repair companies in Ajax post 24/7 hours. The highest-ranked are RCC Waterproofing Toronto (#1), ACCL Basement Wateproofing (#3) and RCC Waterproofing Vaughan (#5). Hours come from each business's Google listing as of October 2026, so call to confirm.
Which foundation repair companies in Ajax work on weekends?
246 of 298 ranked foundation repair companies post Saturday hours and 184 post Sunday hours. The highest-ranked open Saturdays are RCC Waterproofing Toronto (#1), Groundworks (#2) and ACCL Basement Wateproofing (#3). Posted hours are office hours; crews may book weekend jobs separately.
How much does foundation repair cost in Ajax?
Foundation repair typically costs CA$3,130 to CA$11,430, with CA$7,270 typical (Per project: typical range of customer-reported repairs. US national range converted at 1.4054 CAD per USD (Bank of Canada, October 20, 2026)). This is a national range, not adjusted for Ajax. Prices were last checked October 2026. Get at least two written quotes before you hire.
What Google rating do Ajax foundation repair companies have?
The median Google rating among 298 rated foundation repair companies in Ajax is 5.0★, with a median of 26 reviews. Groundworks has the most, 1,412 reviews, and ranks #2. 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 Ajax count in this ranking?
Yes, if they are within 64 km of the Ajax city centre, 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 Ajax
- October 2026: CR Scores recalculated for 298 foundation repair companies serving Ajax.
- October 2026: 1 duplicate listing merged.
More foundation repair companies and Ajax pages
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