# Single-Wall Shallow Underpinning Project in Toronto, ON | Toronto Basement Underpinning URL: https://torontobasementunderpinning.ca/basement-underpinning/toronto/single-wall-shallow-underpin/ Documented Project: Toronto, City of Toronto # Single-Wall Shallow Underpinning Project in Riverdale, Toronto Rear addition needed basement headroom gain without disturbing the front finished basement. Completed by Toronto Basement Underpinning [/ →](/) in March 2024. Fixed-price contract, engineered drawings and City of Toronto permit coordination included. Book a Call About Your Project [/contact/ →](/contact/) Call (416) 900-3329 [tel:+14169003329 →](tel:+14169003329) Licensed & Insured Free Estimate Within 2 Hours Workmanship Warranty on Every Project GTA-Wide Service ![Single-Wall Shallow Underpinning worksite in Riverdale, Toronto, ON - Side wall + rear wall shallow lowering](/images/combos/project-cards/toronto-1.webp) KEY STATS Project Success Metrics Delivered on time and within budget 9.7/10 Total project cost $23,000 Local labor 85% Local supplier spend 100% Building Stats Basement size 760 sqft New area gained 520 sqft Linear footage underpinned 85 lin ft Pins poured 15 Depth gain 2'0" Original ceiling 5'8" Finished ceiling 7'8" Client Homeowner in Toronto Completion March 2024 Location Riverdale, Toronto, ON Sector Residential Permit turnaround 5 weeks Warranty 5 years ## Introduction Rear addition needed basement headroom gain without disturbing the front finished basement. The property is a residential home in Riverdale, Toronto, with an original 5'8" basement ceiling across a 760 sqft footprint. Our crews delivered a side wall + rear wall shallow lowering project under a fixed-price contract that bundled engineered drawings, City of Toronto permit coordination, excavation, pin-by-pin underpinning, interior waterproofing, and new slab pour. The scope lowered the basement by 2'0" to deliver a 7'8" finished ceiling across 520 sqft of newly usable standing-height basement area, directly enabling the homeowner's plan for a legal secondary use of the lower level. ## The Underpinning Process A controlled sequence of engineered steps delivered the Riverdale project on time and within budget. Each phase passed City of Toronto inspection before the next began. ### 1\. Initial Assessment and Planning Site visit confirmed only the rear and side walls required lowering. The front finished basement area was protected with poly containment during the open-pit phase. ### 2\. Excavation Pin-by-pin excavation along 85 linear feet of side and rear perimeter walls to depths of 2 feet below the original slab. ### 3\. Underpinning Pits Mass-poured concrete pins at 24-inch intervals, each pit opened and poured in strict alternating sequence to prevent any run of adjacent open excavation. ### 4\. Steel Reinforcement 15M rebar cages wire-tied vertically to extend the structural column from the existing footing into each new pin. ### 5\. Structural Supports Steel beams on screw jacks held the first-floor carrying structure stable during the deepest pin segments. ### 6\. Waterproofing and Drainage New interior Delta-MS applied along the full re-exposed perimeter, perforated weeping tile set in gravel, battery-backup sump pit installed. ### 7\. Insulation and Finishing New slab poured to grade with a vapor barrier under the gravel bed. Insulation and framing left to the homeowner. ## Our Approach Delivered on time and within budget. The Riverdale project ran through several site challenges: toronto's pre-1960 housing stock was built on native clay with original 6-foot basements poured against dry-stacked stone rubble footings that were never engineered for underpinning without pin-by-pin excavation. We addressed each early by sourcing locally where material shortages hit, scheduling around weather windows, and running hydraulic jacks plus specialised concrete mixes during the deepest excavation phase. Modern waterproofing membranes replaced the aging drainage components, and the result is a basement that is both structurally sound and dry. ## What's Included in This Project Scope The fixed-price contract covered every item below. No line-item surprises, no change orders unless the homeowner added scope. One contract, one warranty, one crew. - Initial site assessment and engineered drawings - City permit application and inspection coordination - Pin-by-pin excavation of side and rear perimeter walls - Mass-poured concrete pins at shallow engineered depth - 15M rebar cages wire-tied vertically to the existing footing - Interior Delta-MS waterproofing along re-exposed perimeter - New perforated weeping tile and battery-backup sump pit - Reinforced slab pour to grade with vapor barrier - Workmanship warranty on all structural work ## Social Impact Crew of five local trades plus one apprentice through the Toronto District School Board co-op program. All concrete and steel sourced from Ontario suppliers. ## Client Testimonials Rated 4.9 stars across projects documented on the site. > ★★★★★ > > "" > ★★★★★ > > "" > ★★★★★ > > "" ## Thinking About Underpinning in Toronto? Every project on this site is delivered on a fixed-price contract with engineered drawings, City of Toronto permits, and a workmanship warranty included. The scope of your project may differ from this one - we size the quote to your actual building, soil, and depth-gain goal. Book a free site assessment and we respond within two business hours. Book a Free Site Assessment [/contact/ →](/contact/) Call (416) 900-3329 [tel:+14169003329 →](tel:+14169003329) ### Other Documented Toronto Projects - Partial Crawl-Space Underpinning in Toronto [/basement-underpinning/toronto/partial-crawl-space-underpin/ →](/basement-underpinning/toronto/partial-crawl-space-underpin/) - Semi-Detached Shared-Wall Underpinning in Toronto [/basement-underpinning/toronto/semi-detached-shared-wall-underpin/ →](/basement-underpinning/toronto/semi-detached-shared-wall-underpin/) - Heritage Rubble-Stone Foundation Underpinning in Toronto [/basement-underpinning/toronto/heritage-rubble-foundation-underpin/ →](/basement-underpinning/toronto/heritage-rubble-foundation-underpin/) - Commercial Café Underpinning in Toronto [/basement-underpinning/toronto/commercial-cafe-underpin/ →](/basement-underpinning/toronto/commercial-cafe-underpin/) - Large Detached Deep Lowering in Toronto [/basement-underpinning/toronto/large-detached-deep-lower/ →](/basement-underpinning/toronto/large-detached-deep-lower/) ### Same Project Type in Other Cities - Single-Wall Shallow Underpinning in Mississauga [/basement-underpinning/mississauga/single-wall-shallow-underpin/ →](/basement-underpinning/mississauga/single-wall-shallow-underpin/) - Single-Wall Shallow Underpinning in Etobicoke [/basement-underpinning/etobicoke/single-wall-shallow-underpin/ →](/basement-underpinning/etobicoke/single-wall-shallow-underpin/) - Single-Wall Shallow Underpinning in Scarborough [/basement-underpinning/scarborough/single-wall-shallow-underpin/ →](/basement-underpinning/scarborough/single-wall-shallow-underpin/) - Single-Wall Shallow Underpinning in North York [/basement-underpinning/north-york/single-wall-shallow-underpin/ →](/basement-underpinning/north-york/single-wall-shallow-underpin/) - Single-Wall Shallow Underpinning in Vaughan [/basement-underpinning/vaughan/single-wall-shallow-underpin/ →](/basement-underpinning/vaughan/single-wall-shallow-underpin/)