What is Vacuum Excavation?
Vacuum Excavation is a safe and efficient method for soil removal. This non-intrusive technique eliminates damage to underground services. Our system works by directing a high-pressure water jet or compressed air into the ground via a lance breaking up the soil. A powerful vacuum sucks up the loosened material through a hose into a storage tank mounted on a trailer or vehicle.
Why use Vacuum Excavation?
Vacuum Excavation is a precise, non-intrusive, non-destructive method of soil excavation that ensures no damage to underground services. It is a significantly more productive than traditional hand digging methods. Shovels, digging grafts and pinch bars can easily damage services leading to expensive repair bills, delays and risk of injury to workers.
How does Vacuum Excavation work?
Vacuum Excavation is a high suction power unit that can use air or water to loosen soil material and perform precision extraction. First, the soil is loosened using either a pneumatic soil pick or a high-pressure water lance. The loose material is then vacuumed into a tank. There are two methods of vacuum excavation.
Pneumatic / Air Method:
The pneumatic method uses compressed air injected into the ground via a lance at 1500mph. The compressed air quickly decompresses in the ground reverting to atmospheric pressure
breaking up and loosening the material in the ground. Pneumatic method is only suitable in granular material (sand and gravel sized material) where the compressed air can penetrate around the granular material and loosen it up. Compressed air cannot penetrate cohesive soils (clay, silt) therefore the hydro / water method would be adopted. If the pneumatic method is used the excavated material is kept dry and suitable for back filling.
Hydro / Water Method:
The hydro system uses high-pressured water (3000psi) injected into the ground via a lance fitted with a rotating head that directs the water jet in a circular motion.
Hydro excavation is suitable in all geology types including clay, sand and gravel. In clay soils, the excavated material is left with slurry that is not suitable for backfilling.
- Inspection pits prior to drilling boreholes
- Slot trenches to locate services prior to traditional mechanical excavation
- Remove contaminated soil from around services or tree roots
- Expose building foundations for structural surveys