Cost to Cut a Basement Floor for a Bathroom Drain: 8 Jobs (2026 Baseline)
Eight basement jobs priced line by line, from a 12 ft slab trench to a full bathroom's drains: the tie-in to old cast iron, an ejector pit, an up-flush toilet, a raised platform, a laundry sink and the camera inspection first. Every line itemized, with crew hours.
Eight builds, side by side
Eight jobs on the same researched rates: the concrete work alone, a bathroom's drains, the tie-in at the stack, three fixes for a sewer that is too shallow (an ejector pit, an up-flush toilet, a raised platform), a laundry sink and the camera inspection to do first.
| Build | Job cost | Labor | Crew hours | Materials | Illustrative selling price |
|---|---|---|---|---|---|
| A. 12 ft trench, concrete only | $1,290 | $744 | 9 to 16 h | $126 | $1,677 to $2,580 |
| B. Bathroom drains, 20 ft | $3,733 | $2,870 | 30 to 43 h | $443 | $4,852 to $7,465 |
| C. Tie-in at the cast iron stack | $1,951 | $1,463 | 10 to 15 h | $293 | $2,536 to $3,902 |
| D. Sewage ejector pit | $4,033 | $2,297 | 20 to 29 h | $1,316 | $5,243 to $8,066 |
| E. Up-flush toilet | $3,002 | $1,465 | 12 to 18 h | $1,537 | $3,902 to $6,004 |
| F. Raised platform over the drains | $1,159 | $795 | 10 to 18 h | $364 | $1,507 to $2,318 |
| G. Laundry sink, 10 ft trench | $3,236 | $2,460 | 24 to 32 h | $356 | $4,206 to $6,472 |
| H. Camera and locate first | $325 | $325 | 1 to 2 h | $0 | $423 to $650 |
Materials include allowances. Illustrative selling price is the job cost at a 30% to 100% markup; your price depends on your own overhead and profit. Labor hours are a planning range and include setup, daily cleanup and material runs; they are never a charge to the customer. Permit and inspection fees are not included; requirements vary by jurisdiction.
Which price is closer to yours?
- Low-Overhead, +30%: A handyman or owner-operator who does the work with a small crew and no office. Usually the lowest quote. The owner handles scheduling, questions and callbacks around the work itself.
- Established, +50%: A remodeling company with a crew, an office, insurance and someone to answer the phone. Close to the average remodeler's overhead in the National Association of Home Builders cost-of-doing-business survey.
- Full-Service, +100%: A design-build firm with designers, a salesperson and a project manager who runs the job. The extra pays for planning, coordination and one point of contact from design to final inspection.
Higher markup means more business behind the job, not by itself better work, and a lower markup is not by itself a better deal. For contractors: how each markup splits into overhead and profit is in the overhead categories guide.
Each build in detail
A. 12 ft trench, concrete only: $1,290
Saw-cut, break out, dig 18 in deep, haul, gravel backfill and a concrete patch; the plumbing is by others. Labor is $744 of the $1,290 job cost, or 57.7%. It is about 9 to 16 hours of work, including setup, daily cleanup and material runs.
Labor cost by trade
Labor only. Materials, allowances and dump fees are in the line items below. Hours are person-hours at typical production from Clamp’s labor hours catalog, as a range: a planning figure, not a schedule and not a charge to the customer.
| Trade | Hours | Labor cost | Low-Overhead×1.30 | Established×1.50 | Full-Service×2.00 |
|---|---|---|---|---|---|
| Plumbing | 7 to 14 h | $744 | $967 | $1,116 | $1,488 |
| Setup, cleanup and material runs | 1 to 3 h | in the prices | |||
| All labor | 9 to 16 h | $744 | $967 | $1,116 | $1,488 |
Every line item
Labor $744 + materials and allowances $126 + dump fees and other $420 = $1,290 direct job cost. Hours are person-hours at typical production, on labor rows only, and the direct-cost row adds about 15% for setup, daily cleanup and material runs; an allowance or material row names the labor line that installs it, and a subcontract row has none, because the sub’s price includes their own time. Some labor quantities include a difficulty factor, so they can exceed the measured area; each row’s derivation is in the downloadable data.
| Item | Qty | Unit | Hours | Labor | Material | Line cost |
|---|---|---|---|---|---|---|
| Demo & Prep | ||||||
| Haul-Off Per Load | 1 | ea | $0 | $0 | $225 | |
| Demo & Prep subtotal | $225 | |||||
| Demo & Prep subtotal | $225 | |||||
| Plumbing | ||||||
| Slab Cutting Equipment and Dust Control (per job) | 1 | ea | $0 | $0 | $195 | |
| Slab Saw-Cut and Trench (per lf) | 12 | lf | 5 to 12 h | $576 | $0 | $576 |
| Slab trench backfill and concrete patch labor | 12 | lf | 1 to 4 h | $168 | $0 | $168 |
| Slab Trench Backfill and Concrete Patch (per lf)Labor on: Slab trench backfill and concrete patch labor | 12 | lf | $0 | $126 | $126 | |
| Plumbing subtotal | 7 to 14 h | $1,065 | ||||
| Plumbing subtotal | 7 to 14 h | $1,065 | ||||
| DIRECT JOB COST | 9 to 16 h | $1,290 | ||||
| DIRECT JOB COST | 9 to 16 h | $1,290 | ||||
B. Bathroom drains, 20 ft: $3,733
Toilet, shower and sink drains in 20 ft of trench, tied into the old drain, tested, inspected and patched. Labor is $2,870 of the $3,733 job cost, or 76.9%. It is about 30 to 43 hours of work, including setup, daily cleanup and material runs.
Labor cost by trade
Labor only. Materials, allowances and dump fees are in the line items below. Hours are person-hours at typical production from Clamp’s labor hours catalog, as a range: a planning figure, not a schedule and not a charge to the customer.
| Trade | Hours | Labor cost | Low-Overhead×1.30 | Established×1.50 | Full-Service×2.00 |
|---|---|---|---|---|---|
| Plumbing | 25 to 38 h | $2,870 | $3,731 | $4,305 | $5,740 |
| Setup, cleanup and material runs | 2 to 8 h | in the prices | |||
| All labor | 30 to 43 h | $2,870 | $3,731 | $4,305 | $5,740 |
Every line item
Labor $2,870 + materials and allowances $443 + dump fees and other $420 = $3,733 direct job cost. Hours are person-hours at typical production, on labor rows only, and the direct-cost row adds about 15% for setup, daily cleanup and material runs; an allowance or material row names the labor line that installs it, and a subcontract row has none, because the sub’s price includes their own time. Some labor quantities include a difficulty factor, so they can exceed the measured area; each row’s derivation is in the downloadable data.
| Item | Qty | Unit | Hours | Labor | Material | Line cost |
|---|---|---|---|---|---|---|
| Demo & Prep | ||||||
| Haul-Off Per Load | 1 | ea | $0 | $0 | $225 | |
| Demo & Prep subtotal | $225 | |||||
| Demo & Prep subtotal | $225 | |||||
| Plumbing | ||||||
| Below-Slab Drain Pipe Install (per lf) | 20 | lf | 3 to 9 h | $680 | $0 | $680 |
| Drain Water Test and Rough-In Inspection (per job) | 1 | ea | 1 to 2 h | $175 | $0 | $175 |
| Tie-In Wye and Transition Couplings (per tie-in) | 1 | ea | $0 | $95 | $95 | |
| DWV MaterialsLabor on: Below-Slab Drain Pipe Install (per lf) | 22 | lf | $0 | $138 | $138 | |
| Slab Cutting Equipment and Dust Control (per job) | 1 | ea | $0 | $0 | $195 | |
| Slab Saw-Cut and Trench (per lf) | 20 | lf | 9 to 19 h | $960 | $0 | $960 |
| Slab trench backfill and concrete patch labor | 20 | lf | 2 to 6 h | $280 | $0 | $280 |
| Slab Trench Backfill and Concrete Patch (per lf)Labor on: Slab trench backfill and concrete patch labor | 20 | lf | $0 | $210 | $210 | |
| Tie In to the Existing Cast Iron or Clay Drain (per tie-in) | 1 | ea | 1 to 4 h | $350 | $0 | $350 |
| Vent Extension Labor | 1 | ea | 2 to 6 h | $425 | $0 | $425 |
| Plumbing subtotal | 25 to 38 h | $3,508 | ||||
| Plumbing subtotal | 25 to 38 h | $3,508 | ||||
| DIRECT JOB COST | 30 to 43 h | $3,733 | ||||
| DIRECT JOB COST | 30 to 43 h | $3,733 | ||||
C. Tie-in at the cast iron stack: $1,951
A 3 by 3 ft opening at the stack, a wye with matched couplings, a cleanout, a test and the patch. Labor is $1,463 of the $1,951 job cost, or 75.0%. It is about 10 to 15 hours of work, including setup, daily cleanup and material runs.
Labor cost by trade
Labor only. Materials, allowances and dump fees are in the line items below. Hours are person-hours at typical production from Clamp’s labor hours catalog, as a range: a planning figure, not a schedule and not a charge to the customer.
| Trade | Hours | Labor cost | Low-Overhead×1.30 | Established×1.50 | Full-Service×2.00 |
|---|---|---|---|---|---|
| Masonry | 3 to 7 h | $650 | $845 | $975 | $1,300 |
| Plumbing | 4 to 8 h | $813 | $1,057 | $1,220 | $1,626 |
| Setup, cleanup and material runs | 1 to 3 h | in the prices | |||
| All labor | 10 to 15 h | $1,463 | $1,902 | $2,195 | $2,926 |
Every line item
Labor $1,463 + materials and allowances $293 + dump fees and other $195 = $1,951 direct job cost. Hours are person-hours at typical production, on labor rows only, and the direct-cost row adds about 15% for setup, daily cleanup and material runs; an allowance or material row names the labor line that installs it, and a subcontract row has none, because the sub’s price includes their own time. Some labor quantities include a difficulty factor, so they can exceed the measured area; each row’s derivation is in the downloadable data.
| Item | Qty | Unit | Hours | Labor | Material | Line cost |
|---|---|---|---|---|---|---|
| Masonry | ||||||
| Sewer Cleanout Slab Break Labor | 1 | ea | 3 to 7 h | $650 | $0 | $650 |
| Masonry subtotal | 3 to 7 h | $650 | ||||
| Masonry subtotal | 3 to 7 h | $650 | ||||
| Plumbing | ||||||
| Drain Water Test and Rough-In Inspection (per job) | 1 | ea | 1 to 2 h | $175 | $0 | $175 |
| Tie-In Wye and Transition Couplings (per tie-in) | 1 | ea | $0 | $95 | $95 | |
| Sewer Cleanout Assembly AllowanceLabor on: Sewer Cleanout Install Labor | 1 | ea | $0 | $156 | $156 | |
| Sewer Cleanout Install Labor | 1 | ea | 1 to 3 h | $288 | $0 | $288 |
| Slab Cutting Equipment and Dust Control (per job) | 1 | ea | $0 | $0 | $195 | |
| Slab Trench Backfill and Concrete Patch (per lf) | 4 | lf | $0 | $42 | $42 | |
| Tie In to the Existing Cast Iron or Clay Drain (per tie-in) | 1 | ea | 1 to 4 h | $350 | $0 | $350 |
| Plumbing subtotal | 4 to 8 h | $1,301 | ||||
| Plumbing subtotal | 4 to 8 h | $1,301 | ||||
| DIRECT JOB COST | 10 to 15 h | $1,951 | ||||
| DIRECT JOB COST | 10 to 15 h | $1,951 | ||||
D. Sewage ejector pit: $4,033
A sealed basin and pump in the slab with vent, check valve, shutoff and 15 ft of discharge. Labor is $2,297 of the $4,033 job cost, or 57.0%. It is about 20 to 29 hours of work, including setup, daily cleanup and material runs.
Labor cost by trade
Labor only. Materials, allowances and dump fees are in the line items below. Hours are person-hours at typical production from Clamp’s labor hours catalog, as a range: a planning figure, not a schedule and not a charge to the customer.
| Trade | Hours | Labor cost | Low-Overhead×1.30 | Established×1.50 | Full-Service×2.00 |
|---|---|---|---|---|---|
| Plumbing | 17 to 25 h | $2,297 | $2,986 | $3,446 | $4,594 |
| Setup, cleanup and material runs | 1 to 5 h | in the prices | |||
| All labor | 20 to 29 h | $2,297 | $2,986 | $3,446 | $4,594 |
Every line item
Labor $2,297 + materials and allowances $1,316 + dump fees and other $420 = $4,033 direct job cost. Hours are person-hours at typical production, on labor rows only, and the direct-cost row adds about 15% for setup, daily cleanup and material runs; an allowance or material row names the labor line that installs it, and a subcontract row has none, because the sub’s price includes their own time. Some labor quantities include a difficulty factor, so they can exceed the measured area; each row’s derivation is in the downloadable data.
| Item | Qty | Unit | Hours | Labor | Material | Line cost |
|---|---|---|---|---|---|---|
| Demo & Prep | ||||||
| Haul-Off Per Load | 1 | ea | $0 | $0 | $225 | |
| Demo & Prep subtotal | $225 | |||||
| Demo & Prep subtotal | $225 | |||||
| Plumbing | ||||||
| Drain Water Test and Rough-In Inspection (per job) | 1 | ea | 1 to 2 h | $175 | $0 | $175 |
| DWV Install Labor | 5 | lf | 1 to 4 h | $225 | $0 | $225 |
| DWV MaterialsLabor on: DWV Install Labor | 16.5 | lf | $0 | $103 | $103 | |
| Sewage Ejector Basin and Pump AllowanceLabor on: Sewage Ejector Install | 1 | ea | $0 | $1,150 | $1,150 | |
| Sewage Ejector Install | 1 | ea | 5 to 11 h | $1,100 | $0 | $1,100 |
| Slab Cutting Equipment and Dust Control (per job) | 1 | ea | $0 | $0 | $195 | |
| Slab Saw-Cut and Trench (per lf) | 6 | lf | 2 to 6 h | $288 | $0 | $288 |
| Slab trench backfill and concrete patch labor | 6 | lf | 1 to 2 h | $84 | $0 | $84 |
| Slab Trench Backfill and Concrete Patch (per lf)Labor on: Slab trench backfill and concrete patch labor | 6 | lf | $0 | $63 | $63 | |
| Vent Extension Labor | 1 | ea | 2 to 6 h | $425 | $0 | $425 |
| Plumbing subtotal | 17 to 25 h | $3,808 | ||||
| Plumbing subtotal | 17 to 25 h | $3,808 | ||||
| DIRECT JOB COST | 20 to 29 h | $4,033 | ||||
| DIRECT JOB COST | 20 to 29 h | $4,033 | ||||
E. Up-flush toilet: $3,002
A macerating toilet with a sink into it, 12 ft of discharge and a vent; no concrete cutting. Labor is $1,465 of the $3,002 job cost, or 48.8%. It is about 12 to 18 hours of work, including setup, daily cleanup and material runs.
Labor cost by trade
Labor only. Materials, allowances and dump fees are in the line items below. Hours are person-hours at typical production from Clamp’s labor hours catalog, as a range: a planning figure, not a schedule and not a charge to the customer.
| Trade | Hours | Labor cost | Low-Overhead×1.30 | Established×1.50 | Full-Service×2.00 |
|---|---|---|---|---|---|
| Plumbing | 10 to 16 h | $1,465 | $1,905 | $2,198 | $2,930 |
| Setup, cleanup and material runs | 1 to 3 h | in the prices | |||
| All labor | 12 to 18 h | $1,465 | $1,905 | $2,198 | $2,930 |
Every line item
Labor $1,465 + materials and allowances $1,537 + dump fees and other $0 = $3,002 direct job cost. Hours are person-hours at typical production, on labor rows only, and the direct-cost row adds about 15% for setup, daily cleanup and material runs; an allowance or material row names the labor line that installs it, and a subcontract row has none, because the sub’s price includes their own time. Some labor quantities include a difficulty factor, so they can exceed the measured area; each row’s derivation is in the downloadable data.
| Item | Qty | Unit | Hours | Labor | Material | Line cost |
|---|---|---|---|---|---|---|
| Plumbing | ||||||
| Drain Water Test and Rough-In Inspection (per job) | 1 | ea | 1 to 2 h | $175 | $0 | $175 |
| DWV Install Labor | 7 | lf | 2 to 6 h | $315 | $0 | $315 |
| Up-Flush Macerating Toilet Package Allowance | 1 | ea | $0 | $1,420 | $1,420 | |
| DWV MaterialsLabor on: DWV Install Labor | 18.7 | lf | $0 | $117 | $117 | |
| Sewage Ejector Install | 1 | ea | 2 to 6 h | $550 | $0 | $550 |
| Vent Extension Labor | 1 | ea | 2 to 6 h | $425 | $0 | $425 |
| Plumbing subtotal | 10 to 16 h | $3,002 | ||||
| Plumbing subtotal | 10 to 16 h | $3,002 | ||||
| DIRECT JOB COST | 12 to 18 h | $3,002 | ||||
| DIRECT JOB COST | 12 to 18 h | $3,002 | ||||
F. Raised platform over the drains: $1,159
A 6 by 8 ft platform framed high enough for gravity drains, with a two-riser step; plumbing by others. Labor is $795 of the $1,159 job cost, or 68.6%. It is about 10 to 18 hours of work, including setup, daily cleanup and material runs.
Labor cost by trade
Labor only. Materials, allowances and dump fees are in the line items below. Hours are person-hours at typical production from Clamp’s labor hours catalog, as a range: a planning figure, not a schedule and not a charge to the customer.
| Trade | Hours | Labor cost | Low-Overhead×1.30 | Established×1.50 | Full-Service×2.00 |
|---|---|---|---|---|---|
| Carpentry | 8 to 16 h | $795 | $1,034 | $1,193 | $1,590 |
| Setup, cleanup and material runs | 1 to 3 h | in the prices | |||
| All labor | 10 to 18 h | $795 | $1,034 | $1,193 | $1,590 |
Every line item
Labor $795 + materials and allowances $364 + dump fees and other $0 = $1,159 direct job cost. Hours are person-hours at typical production, on labor rows only, and the direct-cost row adds about 15% for setup, daily cleanup and material runs; an allowance or material row names the labor line that installs it, and a subcontract row has none, because the sub’s price includes their own time. Some labor quantities include a difficulty factor, so they can exceed the measured area; each row’s derivation is in the downloadable data.
| Item | Qty | Unit | Hours | Labor | Material | Line cost |
|---|---|---|---|---|---|---|
| Carpentry | ||||||
| Platform Step at the Door (per step) | 1 | ea | 1 to 4 h | $225 | $0 | $225 |
| Platform Step Materials (per step) | 1 | ea | $0 | $45 | $45 | |
| Sleeper Floor Over Slab, Framing Labor (per sf) | 48 | sf | 6 to 13 h | $570 | $0 | $570 |
| Sleeper Floor Over Slab, Materials (per sf)Labor on: Sleeper Floor Over Slab, Framing Labor (per sf) | 48 | sf | $0 | $319 | $319 | |
| Carpentry subtotal | 8 to 16 h | $1,159 | ||||
| Carpentry subtotal | 8 to 16 h | $1,159 | ||||
| DIRECT JOB COST | 10 to 18 h | $1,159 | ||||
| DIRECT JOB COST | 10 to 18 h | $1,159 | ||||
G. Laundry sink, 10 ft trench: $3,236
10 ft of trench, a 2 in drain tied into the old drain, a vent, water lines and the sink set. Labor is $2,460 of the $3,236 job cost, or 76.0%. It is about 24 to 32 hours of work, including setup, daily cleanup and material runs.
Labor cost by trade
Labor only. Materials, allowances and dump fees are in the line items below. Hours are person-hours at typical production from Clamp’s labor hours catalog, as a range: a planning figure, not a schedule and not a charge to the customer.
| Trade | Hours | Labor cost | Low-Overhead×1.30 | Established×1.50 | Full-Service×2.00 |
|---|---|---|---|---|---|
| Plumbing | 20 to 28 h | $2,460 | $3,198 | $3,690 | $4,920 |
| Setup, cleanup and material runs | 1 to 6 h | in the prices | |||
| All labor | 24 to 32 h | $2,460 | $3,198 | $3,690 | $4,920 |
Every line item
Labor $2,460 + materials and allowances $356 + dump fees and other $420 = $3,236 direct job cost. Hours are person-hours at typical production, on labor rows only, and the direct-cost row adds about 15% for setup, daily cleanup and material runs; an allowance or material row names the labor line that installs it, and a subcontract row has none, because the sub’s price includes their own time. Some labor quantities include a difficulty factor, so they can exceed the measured area; each row’s derivation is in the downloadable data.
| Item | Qty | Unit | Hours | Labor | Material | Line cost |
|---|---|---|---|---|---|---|
| Demo & Prep | ||||||
| Haul-Off Per Load | 1 | ea | $0 | $0 | $225 | |
| Demo & Prep subtotal | $225 | |||||
| Demo & Prep subtotal | $225 | |||||
| Plumbing | ||||||
| Below-Slab Drain Pipe Install (per lf) | 10 | lf | 1 to 5 h | $340 | $0 | $340 |
| Drain Water Test and Rough-In Inspection (per job) | 1 | ea | 1 to 2 h | $175 | $0 | $175 |
| Fixture Set Labor | 1 | ea | 1 to 4 h | $325 | $0 | $325 |
| Tie-In Wye and Transition Couplings (per tie-in) | 1 | ea | $0 | $95 | $95 | |
| DWV MaterialsLabor on: Plumbing Rough-In Per Fixture | 11 | lf | $0 | $69 | $69 | |
| Plumbing Rough-In Per Fixture | 1 | ea | 1 to 3 h | $225 | $0 | $225 |
| Supply Pipe MaterialsLabor on: Plumbing Rough-In Per Fixture | 12 | lf | $0 | $42 | $42 | |
| Slab Cutting Equipment and Dust Control (per job) | 1 | ea | $0 | $0 | $195 | |
| Slab Saw-Cut and Trench (per lf) | 10 | lf | 4 to 10 h | $480 | $0 | $480 |
| Slab trench backfill and concrete patch labor | 10 | lf | 1 to 3 h | $140 | $0 | $140 |
| Slab Trench Backfill and Concrete Patch (per lf)Labor on: Slab trench backfill and concrete patch labor | 10 | lf | $0 | $105 | $105 | |
| Tie In to the Existing Cast Iron or Clay Drain (per tie-in) | 1 | ea | 1 to 4 h | $350 | $0 | $350 |
| Vent Extension Labor | 1 | ea | 2 to 6 h | $425 | $0 | $425 |
| Plumbing subtotal | 20 to 28 h | $2,966 | ||||
| Plumbing subtotal | 20 to 28 h | $2,966 | ||||
| Vanity & Fixtures | ||||||
| Fixture Set MaterialsLabor on: Fixture Set Labor | 1 | ea | $0 | $45 | $45 | |
| Vanity & Fixtures subtotal | $45 | |||||
| Vanity & Fixtures subtotal | $45 | |||||
| DIRECT JOB COST | 24 to 32 h | $3,236 | ||||
| DIRECT JOB COST | 24 to 32 h | $3,236 | ||||
H. Camera and locate first: $325
Camera the main from the cleanout, locate it and mark its direction and depth on the floor. Labor is $325 of the $325 job cost, or 100.0%. It is about 1 to 2 hours of work, including setup, daily cleanup and material runs.
Labor cost by trade
Labor only. Materials, allowances and dump fees are in the line items below. Hours are person-hours at typical production from Clamp’s labor hours catalog, as a range: a planning figure, not a schedule and not a charge to the customer.
| Trade | Hours | Labor cost | Low-Overhead×1.30 | Established×1.50 | Full-Service×2.00 |
|---|---|---|---|---|---|
| Plumbing | 1 to 2 h | $325 | $423 | $488 | $650 |
| Setup, cleanup and material runs | under 1 h | in the prices | |||
| All labor | 1 to 2 h | $325 | $423 | $488 | $650 |
Every line item
Labor $325 + materials and allowances $0 + dump fees and other $0 = $325 direct job cost. Hours are person-hours at typical production, on labor rows only, and the direct-cost row adds about 15% for setup, daily cleanup and material runs; an allowance or material row names the labor line that installs it, and a subcontract row has none, because the sub’s price includes their own time. Some labor quantities include a difficulty factor, so they can exceed the measured area; each row’s derivation is in the downloadable data.
| Item | Qty | Unit | Hours | Labor | Material | Line cost |
|---|---|---|---|---|---|---|
| Plumbing | ||||||
| Camera Inspection Labor | 1 | ea | 1 to 2 h | $325 | $0 | $325 |
| Plumbing subtotal | 1 to 2 h | $325 | ||||
| Plumbing subtotal | 1 to 2 h | $325 | ||||
| DIRECT JOB COST | 1 to 2 h | $325 | ||||
| DIRECT JOB COST | 1 to 2 h | $325 | ||||
Methodology & reproducibility
8 snapshots, one per build. Each build is frozen from its own estimate run with the same old work, system type and takeoff pinned, so the builds differ only in what is being built.
Direct cost equals the sum of each row’s rounded quantity × (labor + material + other). Amounts are shown in whole dollars; every column adds to its total.
Scope selection, prose accuracy, arithmetic and provenance mapping reviewed; not independent market-rate verification.
- basement-slab-trench/v1: JSON, CSV, field dictionary
- basement-slab-bathroom-drains/v1: JSON, CSV, field dictionary
- basement-slab-stack-tie-in/v1: JSON, CSV, field dictionary
- basement-slab-ejector/v1: JSON, CSV, field dictionary
- basement-slab-upflush/v1: JSON, CSV, field dictionary
- basement-slab-platform/v1: JSON, CSV, field dictionary
- basement-slab-laundry-sink/v1: JSON, CSV, field dictionary
- basement-slab-camera/v1: JSON, CSV, field dictionary
Questions
How much does it cost to cut a basement floor for plumbing?
A 12 ft trench through a 4 in slab, cut wet, broken out, dug 18 in deep, hauled away and patched after the plumber is done, is $1,290 in job cost, $1,677 to $2,580 from a contractor. That is the concrete work alone. The saw cut is about 27 ft for 12 ft of trench, because both sides and the ends are cut.
What do the drains for a basement bathroom cost?
A toilet, shower and sink in 20 ft of trench, tied into the existing 4 in drain, water-tested, inspected and patched: $3,733 in job cost, $4,852 to $7,465 from a contractor. HomeGuide puts an ordinary one-bathroom rough-in at $1,500 to $3,000 before any slab cutting; Oakwood Remodeling puts cutting the slab and rerouting drains at $3,000 to $8,000.
What slope does a basement drain need?
Under the International Plumbing Code, 1/4 in per ft for 2 in pipe and 1/8 in per ft for 3 in and larger. A 12 ft run of 2 in drain drops 3 in before the fittings and trap. Uniform Plumbing Code (UPC) areas generally want 1/4 in per ft and allow 1/8 in only on 4 in and larger with approval. Your local code controls.
What if the sewer is too shallow for a basement toilet?
There are three fixes. A sewage ejector basin and pump in the slab is $4,033 in job cost before the drains to it; HomeGuide puts a new system at $2,000 to $5,500. An up-flush macerating toilet is $3,002 with a sink into it, more than HomeGuide's $1,000 to $2,000 because this one includes the vent and 12 ft of discharge. A raised platform over gravity drains is $1,159 for the framing alone.
Does an up-flush toilet need a vent?
Yes. Saniflo's instructions call for a vent connection on the pump and no air admittance valve on that vent, and a shower draining into it sits on a raised base so its trap can drain. No concrete cutting is the main saving.
How high can a bathroom platform be?
Only as high as the headroom allows. The residential code asks for 6 ft 8 in of ceiling height in a bathroom, so a 7 ft 6 in basement leaves about 10 in for the platform and floor. The step up needs two risers, since one riser cannot be over 7 3/4 in. Check the toilet, trap and fall to the main fit under it before you build.
What does tying into the old cast iron stack cost?
Opening the floor 3 by 3 ft at the stack, cutting in a wye with couplings matched to the cast iron and the clay, adding a cleanout, testing and patching: $1,951 in job cost. Use a shielded coupling on the cast iron and a transition rated for clay to plastic under the slab. If the cast iron crumbles or the clay is broken, more pipe has to be replaced.
What about just a laundry sink?
A laundry sink 10 ft from the drain, with the trench, a 2 in drain, a vent, the water lines and the sink set: $3,236 in job cost, $4,206 to $6,472 from a contractor. Most of the cost is the trench and the tie-in, not the sink.
Should I have the drain camera-inspected first?
Yes. A camera run from the cleanout, with the line located and marked on the floor, is $325 in job cost. HomeGuide puts a camera inspection at $125 to $500. Without it you can cut a trench to the wrong place or find the drain too shallow after the floor is open. A locator's depth is an estimate, so confirm the depth before you cut.
Is wet cutting a basement slab dust-free?
No. Water cuts most of the dust, but OSHA's silica rule still calls for respiratory protection for indoor wet sawing. Use an electric saw indoors, never a gas saw, because of carbon monoxide. Every slab job here includes a $195 equipment and dust-control line.
Is the markup on top of these numbers?
Yes. Direct job cost is what the work costs a contractor to do. The markup table shows what it sells for at illustrative markups of 30% to 100%, from a low-overhead owner-operator to a full-service firm. Permits are shown separately.
Sources & provenance
- Ejector Pump Cost HomeGuide (research)
- Toilet Installation Cost HomeGuide (research)
- Sewer Camera Inspection Cost HomeGuide (research)
- Cost to Install New Plumbing Pipes HomeGuide (research)
- 1950s Ranch Home Bathroom Remodel, Sacramento Oakwood Remodeling (research)
- 2021 International Plumbing Code, Chapter 7: Sanitary Drainage International Code Council (official source)
- 29 CFR 1926.1153, Respirable crystalline silica OSHA (official source)
- Saniflo professional catalog Saniflo (research)
- 12 ft trench, concrete only reviewed snapshot Clamp Research
- Bathroom drains, 20 ft reviewed snapshot Clamp Research
- Tie-in at the cast iron stack reviewed snapshot Clamp Research
- Sewage ejector pit reviewed snapshot Clamp Research
- Up-flush toilet reviewed snapshot Clamp Research
- Raised platform over the drains reviewed snapshot Clamp Research
- Laundry sink, 10 ft trench reviewed snapshot Clamp Research
- Camera and locate first reviewed snapshot Clamp Research