Enter the run length and depth, pick a trenchless method, and set the trench width and pit size you are assuming. The calculator multiplies out the ground a full-length trench would dig against the pits the method needs, draws both to scale in plan view, and reports excavated volume, surface opened, hard surface to rebuild and trees whose roots a trench would cross.
- Trench volume is length × width × depth; pit volume is pit count × pit length × pit width × depth.
- Pit count depends on the method: none for lining from a cleanout, two for bursting, slip lining or drilling, plus one per connection for those three.
- Trench width and pit size are your assumptions; edit them to match a contractor's sketch.
- For a residential lateral between 5 and 40 m, it also shows the network's published 2026 planning ranges.
- It measures geometry, not noise, traffic, schedule or risk; the guide on disruption covers those.
Dig vs Trenchless Disruption Calculator
01 /What does the disruption calculator measure?
It measures the one thing everybody argues about and almost nobody quantifies: how much of your property or street is actually opened by each approach. A trenchless sales pitch says "no digging"; a skeptical neighbour assumes the yard will be torn up anyway. Both can be wrong. Lining from a basement cleanout may need no excavation at all, while bursting a lateral with three branch connections needs five holes. The calculator shows the difference for your run, with your numbers, drawn to the same length.
Everything it reports is arithmetic on your inputs. It does not know your soil, the shoring a crew will use, where the utilities are, or how wide a machine needs to work. The defaults are placeholders chosen to be easy to edit, not measurements, and every output is labelled that way.
02 /What do I enter?
| Input | Default | Range | Notes |
|---|---|---|---|
| Length of the run | 20 m | 2 to 300 m | From the camera footage counter or the site plan |
| Depth to the pipe | 2 m | 0.5 to 8 m | Used for both trench and pits |
| Trenchless method | Pipe bursting | Five options | Sets the base number of pits |
| Service connections | 0 | 0 to 10 | Adds a pit each for bursting, slip lining and drilling |
| Trench width assumed | 0.9 m | 0.4 to 3 m | Deep or shored trenches are often wider; ask |
| Pit length × width assumed | 2.5 × 1.5 m | 0.8–12 × 0.8–6 m | Raise the length to model a slip-lining insertion trench |
| Route under hard surface | 30% | 0 to 100% | Driveway, walk, patio or paving |
| Pits in hard surface | 0 | 0 to 12 | When a pit cannot be placed in lawn |
| Trees whose roots cross the route | 1 | 0 to 12 | Counted, not modelled |
The results update as you type. If a number is blank or outside its range, the calculator uses the nearest allowed value.
03 /How many pits does each method need?
| Method in the calculator | Base pits | Plus one per connection? | Why |
|---|---|---|---|
| Lining from a cleanout (CIPP) | 0 | No | The liner goes in through the cleanout; a robotic cutter reopens branches from inside |
| Lining with one access pit | 1 | No | Where no usable cleanout exists, one pit gives access |
| Pipe bursting | 2 | Yes | Launch and receiving pits; SUDAS says every service connection is excavated and disconnected first |
| Slip lining | 2 | Yes | Insertion and receiving; SUDAS says services normally have to be excavated and a new wye installed |
| Directional drilling (new path) | 2 | Yes | Entry and exit dug as small pits in this model; connections are made in open excavations |
Real jobs can need more: a pit at a sharp bend, at a change of material, or where a camera found an obstruction. Add those as extra connections to see their effect. The Method Finder explains which method suits the pipe in the first place, and slip lining and close-fit liners describes why slip lining digs at each service.
04 /How are the results calculated?
- Trench
Area opened = length × trench width. Volume = area × depth. Hard surface to rebuild = area × the share of the route under hard surface.
- Pits
Pit count from the table above. Area opened = count × pit length × pit width. Volume = area × depth. Hard surface = the pits you said must go in a hard surface × pit area.
- Headline
Pit volume as a percentage of trench volume, rounded. With no pits, it reads "No excavation" against the trench volume.
- Badges
Excavation share is marked green at 25% or less, amber up to 60%, red above. Surface and hard-surface rows show the square metres spared.
- Depth note
At 1.2 m or deeper, a note repeats CCOHS guidance that trenches of that depth need a protective system, and that provincial rules apply to pits too.
Volumes are bank volumes, the soil as it sits in the ground. Dug soil takes up more room once loosened, so spoil piles and truckloads are larger than the number shown; the calculator does not apply a bulking factor because that depends on the soil.
05 /Where do the planning ranges come from?
Only for a residential lateral between 5 and 40 m, the calculator adds the network's published 2026 planning figures. Open cut uses $600 to $1,000 per metre for shallow runs under soft ground, and $1,000 to $2,000 per metre when the pipe is deeper than 2.5 m or half or more of the route is under hard surface. Lining is built from setup of $500 to $2,000, $500 to $1,200 per metre, cleaning of $400 to $2,500 and $300 to $1,200 per reopened connection, plus $1,500 to $4,500 for an access pit when one is needed. Bursting is built from setup of $500 to $2,000, $550 to $1,300 per metre and $1,500 to $6,000 per pit.
Slip lining and directional drilling show no range, because this site does not publish residential figures for them. Runs outside 5 to 40 m show no range either: mains, crossings and long runs are priced by tender. None of the ranges include rebuilding hard surfaces or work at the city main.
06 /Worked examples
Defaults: 20 m, 2 m deep, bursting, no connections. The trench opens 18 m² and digs 36 m³, with 5.4 m² of hard surface to rebuild. Two 2.5 × 1.5 m pits open 7.5 m² and dig 15 m³, so the headline reads 42% of the ground a trench would dig, marked amber. Because the pipe is 2 m deep, the protective-system note appears. The planning ranges read about $12,000 to $20,000 for open cut and $14,500 to $40,000 for the bursting parts sum.
The same run, lined from a cleanout, one connection. No pits at all: the headline reads "No excavation vs 36 m³ dug". The lining parts sum to about $11,200 to $29,700.
The same run burst with three connections and one pit forced into the driveway. Five pits open 18.75 m², slightly more than the trench's 18 m², and dig 37.5 m³ against its 36 m³. This is the case the calculator exists for: on a short run with many branches, bursting does not save ground, and a trench or a liner may be the better conversation.
07 /What the calculator leaves out
- Working room. Machines, spoil and a fused pipe string need space beside the hole. Directional drilling in particular needs room to lay out the whole pipe before pullback.
- Time and noise. A trench stays open longer along more of the route; pits concentrate the work. See trenchless vs open cut disruption.
- Settlement. Backfilled trenches can settle along their length; pits settle in patches.
- Risk. Bursting pushes soil outward toward nearby services; open cut exposes them. Neither shows in cubic metres.
For the full money picture, read the trenchless sewer cost guide. When you have a contractor's pit sketch, enter its real dimensions here, then ask for comparable quotes.
FAQQuestions people ask
Why does bursting sometimes dig as much as a trench?
Every service connection on a burst line needs its own pit. On a short run with several branches, those pits can add up to about the same area as a narrow trench.
Why is the trench only 0.9 m wide by default?
It is a placeholder, not a rule. Deeper or shored trenches are often wider. Replace it with the width on your contractor's plan.
Does the calculator include the space for equipment?
No. It counts only ground that is excavated. Machines, spoil piles and pipe lay-down need extra room that is occupied but not dug.
Why is there no price for slip lining or drilling?
This site publishes residential planning ranges only for lining, bursting and open cut. Other methods are priced by quote or tender.
NETWORKGo deeper across the HAUSE Sewer network
Trenchless lining vs pipe bursting: cost, fit and trade-offs
Trenchless lining vs pipe bursting cost in Canada: 2026 CIPP and bursting ranges in CAD, line items, which defects each fixes and how to choose.
SewerRoots.caRoot Risk Calculator
Root Risk Calculator: enter tree species, distance to the sewer line, pipe material, age and root history to get a risk band, the reasons and next steps.
SewerJetting.caJetting before trenchless lining: why the prep cleaning decides the result
Why jetting before trenchless lining matters: root removal, descaling cast iron, cleaning to a bare wall, camera checks and what rushed CIPP prep causes.