Why Demolition Dust Is Different
Dust from demolition work is not the same as general construction dust. Demolition of concrete structures, brick masonry, and composite buildings generates respirable crystalline silica (RCS) — the most hazardous common construction dust. Demolition of older buildings adds further hazards: asbestos-containing materials (ACMs), lead paint dust, and biological contamination from animal or bird occupancy.
The combination of high dust generation rates — demolition impact, structure collapse, and mechanical processing all generate large dust clouds — with the presence of multiple hazardous materials makes dust control on demolition sites a priority COSHH and CDM obligation, not an afterthought.
System Types: A Comparison
Open Hose Suppression
The simplest approach: a garden or industrial hose pointed at the dust source. Requires a mains connection or static water tank. Coverage is limited to where the hose reaches, water consumption is high (no atomisation), and a second operative is required to manage the hose. Effective for small, static dust sources. Impractical for a moving demolition front.
Fixed Cannon Systems
A water cannon mounted on a fixed base, connected to mains water and a power supply. Wide coverage area (up to 70–80 metres for large units), oscillating head for area suppression. Requires permanent infrastructure — mains water, power, mounting structure. Best for fixed operations such as aggregate processing or quarry applications. Impractical for demolition where the work front moves daily.
Mobile Cannon Units with Mains Connection
A wheeled or skid-mounted cannon connected to mains water via hose. Mobile within hose reach. More flexible than fixed systems but still constrained by hose infrastructure — on a demolition site, hose runs from a standpipe to the work front may be 50–100 metres or more, creating trip hazards and pressure loss issues.
Self-Contained Mobile Cannon Units
The most operationally practical solution for demolition. Integrates the water tank, cannon, pump and power source in a single relocatable unit. No mains connection. No hose infrastructure across site. Repositioned to follow the demolition front by the site excavator.
The MW Equipment DustBag is a self-contained 2,000L dust suppression unit with 180° oscillating water cannon and up to 5 hours of operation without mains refill. Repositioned by site excavator — no hose runs, no mains, no second machine. Learn more about the DustBag →
What to Specify
When specifying dust suppression for a demolition project, the key decisions are:
- Tank capacity — how long do you need between refills? A 2,000L tank at typical suppression rates gives 4–6 hours of operation before refilling is needed
- Cannon range — how far from the suppression unit will the active demolition front be? 30 metres covers most close-working demolition; longer ranges suit larger footprint operations
- Power source — diesel engine for full site independence; hydraulic drive (from excavator hydraulics) for the cleanest installation; mains electric where it's reliably available
- Repositioning mechanism — how will the unit be moved as the front advances? Chain lifting requires a second operative; the Easy-Lift System allows single-operator repositioning by the site excavator
- Oscillation — a cannon that oscillates across its coverage arc gives far better coverage than a fixed-direction unit
Environmental Permit Considerations
Large demolition sites in England may require an environmental permit from the Environment Agency — particularly where waste processing, asbestos removal or other controlled activities are involved. The permit may specify dust control requirements that must be met throughout the demolition programme. Evidence of compliant suppression equipment on site — including inspection and maintenance records — supports permit compliance audits.