CSLB License #752427 · C-12 Earthwork & Paving  ·  Insured & Bonded  ·  Mon–Sun · 7:00 AM – 7:00 PM Call or text: (805) 217-3863
HomeGuidesThe Excavation Glossary: Your Quote, Tra
Dig Terms in Plain English

The Excavation Glossary: Your Quote, Translated

Every trade has its language, and excavation quotes are full of it. Here's what the words on your bid actually mean — defined by the crew that uses them daily, not a content mill.

🕑 Updated August 2026 · reviewed quarterly

Bank yards vs. loose yards

Bank yards measure soil in the ground; loose yards measure it after digging, when swell has expanded it 20–30%. Quotes and truckloads use loose yards; hole math uses bank yards.

Dig sheet

The pool builder's excavation drawing: dimensions, depths, step and bench locations, and over-dig allowances. We dig to it — 'to print' — so steel and plumbing fit without rework.

Over-dig

The extra inches excavated beyond the pool's finished shape to leave room for steel and plumbing. Typically 3–12 inches depending on the design. Too little jams the trades; too much wastes gunite.

Spoil

The excavated material itself. A 16×32 pool makes ~130 loose yards of spoil — see the truckload guide.

Swell factor

How much soil expands when excavated — commonly 1.2–1.3× for dirt, more for rock. The reason the pile is always bigger than the hole.

Compaction lift

A layer of fill (typically 6–8 inches) placed, moisture-conditioned, and compacted before the next layer goes on. Engineered fill is built lift by tested lift.

Certified pad

A building pad whose engineered fill was compaction-tested by a licensed soils engineer, documented in a report the building department accepts.

Keyway

A trench cut into firm ground at the base of a slope fill, locking the new fill into competent material so the slope can't slide on a smooth plane.

Bench (slope)

Steps cut into an existing slope before placing fill against it — same locking principle as a keyway, repeated up the hill.

Scarify

To rip and loosen the top layer of a pad so new fill bonds to it during recompaction — standard first step in fire-rebuild pad recertification.

DigAlert (811)

California's free utility-marking service. State law requires contacting DigAlert at least two working days before digging so buried utilities get marked.

Rock clause

The contract term defining how rock excavation is priced if encountered. Read the full guide — never dig without one.

Caisson / grade-beam pool

A hillside pool design supported on drilled concrete piers (caissons) tied by grade beams — the excavation follows the structural plan, not just the pool shape.

Tightline

A solid (non-perforated) drain pipe that carries collected water — from downspouts or area drains — to a legal discharge point.

French drain

A gravel-filled trench with perforated pipe that intercepts subsurface water and carries it away. Surface water wants area drains instead — different problem, different pipe.

Positive drainage

Ground sloped so water flows away from structures — building code expects roughly 5% fall for the first 10 feet from a foundation.

Export / import

Hauling soil off site (export) or bringing approved fill in (import). Priced by loads, distance, and material.

Compaction test

A field density test (nuclear gauge or sand cone) verifying fill was compacted to spec — typically 90%+ relative compaction for structural fill.

Term on your quote we didn't cover? Ask us — decoding bids is free.

Ready to break ground?

Free site visits and same-week estimates across Ventura & Los Angeles counties. Call, text, or send the job details.

Call (805) 217-3863  Request a Free Estimate