Construction glossary
Swell and shrink
Also called bank versus loose, load factor, shrink factor.
Dirt changes volume when you dig it and when you compact it. Swell is bank to loose. Shrink is bank to compacted. If you count trucks on bank cubic metres, you will be short.
Typical factors (confirm on site)
DIRT’s defaults match common field books: sand/gravel about 12% swell, common earth about 25%, clay about 30%, blasted rock about 50%. Shrink on placement is a different number — common earth often around 12%. These are starting points, not a soils report.
The conversion
Loose = bank × (1 + swell). Compacted = bank × (1 − shrink). Load factor is 1 / (1 + swell). A 100 m³ bank cut of common earth is about 125 m³ loose in the truck. Run the swell calculator before you size the haul.
Swell and shrink FAQ
Is trench volume in DIRT bank or loose?
Bank, from the dimensions you type. Apply swell before you count trucks.
What is load factor?
Bank volume per unit of loose volume: 1 / (1 + swell). A 25% swell is a 0.80 load factor.
Use your agreed rates on every daily ticket.
These public ranges are a benchmark. SubTrack stores the rates you agreed with the client on a project rate sheet. Crews apply those rates to labor, equipment, materials, and subcontractors on the daily ticket. The same figures carry into reporting and the billing documents you send.