Sprayed Concrete (Shotcrete)

Shotcrete is concrete pneumatically projected at high velocity onto a surface to form structural linings.
It is used in tunnels, retaining walls, slope stabilisation, and swimming pool construction.
The spraying process creates significant rebound — concrete particles bounce back at high speed.
Rebound material hits exposed skin, eyes, and the body, causing abrasion and concrete burns.
Cement dust and concrete mist in the spray zone require RPE with a minimum APF of 20.
The nozzle pressure and velocity make the spray hose difficult to control and hazardous if released.
Alkaline accelerators added to shotcrete are corrosive to skin and eyes on contact.
COSHH 2002 applies to exposure from cement dust, accelerators, and concrete mist during spraying.
The spray zone must be cleared of unnecessary personnel — only the nozzle operator and assistant remain.
Noise levels during shotcreting typically exceed 90 dB, requiring hearing protection for all nearby workers.

Rebound injuries	High-velocity concrete rebound strikes exposed skin and eyes causing serious injury.
Chemical burns	Wet concrete and alkaline accelerators cause deep skin burns on prolonged contact.
Respiratory hazard	Cement dust and concrete mist in the spray zone damage lungs without RPE.
Hose control	An uncontrolled high-pressure spray hose whips violently and can injure the operator.

Do

Don't

Wear full face protection, RPE, waterproof coveralls, and gloves during spraying.
Clear all unnecessary personnel from the spray zone before starting work.
Secure the spray hose and maintain control of the nozzle at all times.
Wear hearing protection — shotcreting noise exceeds safe exposure limits.
Read the safety data sheet for all accelerators and admixtures before use.
Wash any concrete or accelerator splash off skin immediately with clean water.
Inspect the spray pump, hoses, and nozzle before every spraying session.
Brief the team on the spray sequence, exclusion zone, and emergency procedures.
Use dust suppression and ventilation when spraying in enclosed or confined areas.
Ensure eyewash stations are available near the spraying work area.

DON'T spray without full face protection, RPE, and waterproof clothing.
DON'T allow personnel into the spray zone who are not directly involved.
DON'T release the nozzle while the pump is operating — the hose whips violently.
DON'T handle accelerators or admixtures without chemical-resistant gloves.
DON'T spray in confined spaces without forced ventilation and gas monitoring.
DON'T ignore rebound build-up — it reduces bond strength and must be removed.
DON'T eat, drink, or smoke in the spraying area without washing hands first.
DON'T stand directly in front of the spray direction when working as assistant.
DON'T skip pre-use checks on spray equipment — blockages cause pressure surges.
DON'T point the nozzle at people even when the pump is not running.

See also: Concrete Pour Safety | Concrete Burns Prevention

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