Project Case Study. Markham. Full residential sewer lateral replacement, house to municipal main. Free on-site quote: 416-317-3090
Markham Sewer Lateral Replacement — Clay Soil, Open-Cut, House to Main
A Markham homeowner was tired of plunging the floor drain after every storm. Plumber’s camera showed an offset joint 18 ft. out, clay tile original to the build, maple roots through the gap. Four days, open-cut from foundation to city tap, ABS swap, driveway back together. Free assessment: 416-317-3090.
Project Snapshot
- Location: 16th Avenue area, Markham (street corridor only)
- Job type: Residential sewer lateral replacement, house to municipal main, open-cut
- Crew: 3, plus shoring rental and licensed plumber for the inside connection
- Timeline: 4 working days on site, 3 weeks from quote to start (permit window)
- Equipment: Yanmar SV40, Vio17 (38 in. tracks, 39 in. gate buffer), GEHL RT135, trench box for 6-8 ft. depth
- Approximate cost: $7,500-$14,000 all-in (open-cut, includes permit, tap, restoration)
- Permits: City of Markham building permit (plumbing), Ontario One Call locates
The Setup
1980s two-storey on a 45 ft. lot. Vitrified clay tile lateral, 4 in. diameter, original to the build. Basement backups every heavy rain for two seasons. Plumber’s camera tagged an offset joint at the 18 ft. mark, root mat through the gap, standing water past it. Soil profile in this part of Markham reads heavy clay over till, holds water, swells and shrinks with the seasons. The front-yard maple trunk sat seven feet off the line. Roots travel.
The lateral ran straight out the front, under the driveway, through the boulevard to the city main. Neighbour’s interlock driveway six feet off our trench line. Gas service on the right, separate corridor, marked on the locates. Frost cover put the new line at 6-8 ft., which means a trench box. No way around it on clay this stiff.
The Plan
Open-cut or trenchless. We are an open-cut shop. Trenchless pipe bursting can work on a straight run with no service taps, but on a 45 ft. front yard the launch and receiving pits still need digging and the cost lands within $500 of open-cut. Open-cut also let us replace the full run including the city tap.
Permit was a City of Markham building permit, plumbing component, filed by the plumber. Ontario One Call locates put gas, electrical, communications, and water on the lawn in paint and flags. Pipe choice was ABS, 4 in. solid wall, glued joints, bedded on 6 in. of granular A. Shoring was a 4 ft. by 8 ft. aluminum trench box past 5 ft. depth.
Traffic plan was simple. The cut crossed the driveway, so the homeowner parked on the street for four days. Boulevard stayed open to pedestrians via a steel road plate at end of shift.
The Execution
Day 1. Locates verified. Saw-cut the driveway along chalk lines, lifted the slab in three pieces with the SV40, stacked clean for reuse. First cut at the foundation wall, exposed the clay tile cleanout. Licensed plumber on site to disconnect the inside line and cap. Hand-trench the last 8 ft. near the maple to protect the root mat. Surprise of the week: hit a buried gas marker tape at 3 ft. that the locates had not flagged. Stopped, called the gas utility for a re-locate, got an updated mark within the hour. No actual line, old marker from a 1990s service upgrade, but we do not dig past a tape until a utility truck signs off.
Day 2. Trenched through the driveway and across the boulevard to the main. Trench box walked along as the cut advanced. Depth at curb was 7 ft. 4 in. to match the main invert. City inspector watched the saddle go on, signed the permit card. New ABS run on the granular bed, joints glued, pressure test held overnight.
Day 3. Backfill. Granular A in 8-inch lifts to 18 in. above pipe crown, jumping jack inside the trench box, plate compactor above. Native clay back in lift by lift, plate after every 8 in. Hand-trench section by the maple got the same treatment, slower, by hand. Density check at three points by a CET-stamped tester, all at or above 95 percent standard Proctor.
Day 4. Reinstatement. Driveway pieces reset where intact, cut zone framed and poured fresh by our concrete sub, broomed to match. Boulevard capped with topsoil and rolled sod. Lawn portion seeded and pegged with straw mat. Site walk, flow test from the basement floor drain end to end, signed off.
The Result
New ABS lateral, foundation wall to city tap. Pressure test held, flow test ran clean from the basement floor drain to the main, no pooling, no back-pressure. Compaction documented to 95 percent standard Proctor across three test points. Driveway poured back, boulevard sodded, lawn seeded. No more plunging the floor drain after a storm. The maple kept its root mat.
Cost Breakdown
Rough ranges for a comparable Markham open-cut sewer lateral replacement, 45-50 ft. run through clay, single driveway cut, single boulevard cut. This job landed mid-range.
| Phase | Cost Range | Notes |
|---|---|---|
| Permit, locates, site setup | $600-$1,100 | Markham building permit, Ontario One Call, gas re-locate |
| Excavation, trench box, shoring | $2,400-$4,200 | SV40 + Vio17, 4×8 aluminum trench box rental, 4 days |
| Pipe, fittings, bedding | $900-$1,600 | 4 in. ABS, granular A bed, glued joints, cleanout |
| City tap and inspector connection | $1,400-$2,300 | Saddle tap on main, City of Markham inspection |
| Backfill, compaction, density testing | $1,100-$2,000 | Granular A in 8-in. lifts, third-party density gauge |
| Driveway and sod restoration | $1,100-$2,800 | Concrete patch sub, sod over boulevard, seed on lawn |
| All-in scope | $7,500-$14,000 | Open-cut, excludes inside plumbing rework past the foundation wall |
What We Would Do Differently
Book the concrete sub on the calendar the day the permit clears, not the morning of Day 4. We had a half-day gap between trench cap and patch pour because the sub was finishing a job in Vaughan. Homeowner parked on the street one extra night for no good reason. On the next two lateral jobs we locked the patch crew in as soon as the locate window closed and the gap disappeared.
Want a Similar Project Done?
OCM Excavation runs sewer lateral replacements and underground utility work across Markham, Richmond Hill, Vaughan, Toronto, and the GTA. Open-cut, permits handled, restoration included. Free on-site quote in 24-48 hours. Call 416-317-3090.