The number a homeowner wants is a published “$25 a foot installed” special, or a “$40 a linear foot” coupon. That number is not a takeoff. A 40-foot shallow 4-inch daylight trench in dirt is not the same job as an 80-foot deep 6-inch run in clay that has to hit a drywell, two catch basins, three downspout ties, and a driveway crossing. The trip is the same. The hours are not.
Open the free bid calculatorBasement-waterproofing calculators price interior perimeter drain, window wells, and a sump pit. Gutter-install calculators price K-style, miters, and fascia. An exterior yard drain is a different job: the trench, the pipe, the outlet, and the extras that are not in the coupon. Quoting all of that from a published per-foot special is how the first rock ledge and the first saw-cut eat the field margin.
Each extra foot of depth is time and gravel that never appears on the coupon. Clay, a drywell, catch basins, downspout ties, and a driveway crossing are billed as their own hours. On the sample rates an 80-foot deep 6-inch clay drywell run with two basins, three downspouts, a 15-foot driveway crossing, lawn restore, and tear-out of spoils prices about $8,824.85 (45.3 crew-hours, $110.31 per foot). The same shop’s 40-foot shallow daylight trench prices about $1,862.64 (9.3 hours, walk-away $1,303.85, $46.57 per foot). Matching the brochure job’s $25/ft special ($1,000 on 40 feet, $2,000 on 80 feet) on the clay drywell yard is how that job becomes a loss — the walk-away on the heavy job is already $6,177.40, and the $2,000 special loses about $4,177 there. The $1,000 special loses $303.85 even on the brochure trench.
A 50-foot standard 4-inch storm tap with one basin and 30 feet of solid pipe to the outlet is not the 40-foot brochure trench plus 15%. On the sample rates that storm job prices about $3,829.47 (18.8 crew-hours). A daylight outlet drops drywell hours; depth and clay do not disappear with the daylight. Treating either as a blended add-on is how the special that looked fine turns into a loss after the first rock ledge.
A $42/h operator loaded at 30% payroll burden is $54.60. Margin is a share of the price you send, not a markup on cost. The walk-away price is total cost — below that the job makes nothing before you take a dollar home. Replace every rate with your invoices before you send either number.
This is not a drainage design, a building-code determination, a permit, an engineering stamp, or a recommended market price. It is arithmetic on the numbers you type. The run, the depth, pipe, soil, outlet, and basins are yours to confirm. It does not price an interior basement waterproofing job or a gutter install.
Charge from the trip, the trench (depth times soil), pipe size, the outlet (daylight, drywell, or storm tie-in), catch basins, downspout ties, driveway crossings, extra solid pipe, lawn restore, loaded labor, overhead, and a margin that is a share of price. A default 40-foot shallow 4-inch daylight trench in dirt, at the sample rates in this calculator, prices around $1,863 — about 9.3 crew-hours, $46.57 per foot.
Homeowners count linear feet. Depth, clay, a drywell, basins, and a driveway do not scale with that number. Matching a cheaper special written for a 40-foot daylight trench is how an 80-foot clay drywell job becomes a two-day loss. On the sample rates the $25/ft special already loses about $304 on the brochure trench (walk-away $1,304) and loses about $4,177 on the clay drywell yard whose walk-away is already $6,177.
An 80-foot deep 6-inch run in clay with a drywell, two catch basins, three downspout ties, and a 15-foot driveway crossing is not a 40-foot shallow special. On the sample rates that job prices around $8,825 (45.3 crew-hours, $110.31 per foot), while a 40-foot shallow daylight trench prices around $1,863 (9.3 hours).