Shotcrete & Gunite

The difference between gunite and shotcrete comes down to when water is added to the concrete mix.

Gunite is a dry-mix process, where dry cement and aggregate are carried through the hose and mixed with water at the nozzle. On the other hand, shotcrete is a wet-mix process, where the concrete is mixed with water before it is pumped and sprayed into place.

Both methods use high-pressure application to place concrete onto a prepared surface. The right choice depends on the project size, access, finish, structural requirements and level of control needed during application.

Gunite gives the nozzle operator greater control over the water content as the material is sprayed. This can make it useful for repairs, detailed shaping and smaller or more complex applications.

Wet-mix shotcrete is often preferred for larger projects because the mix is prepared before spraying. This can improve consistency, reduce dust, minimise rebound and support faster application across larger areas.

If you’re not sure which method is most suitable for your requirements, contact our expert applicators for tailored advice today.

Shotcrete delivers the same core benefits as conventional concrete, including high compressive strength, thermal mass, fire resistance and low permeability. However, it stands out for its ease of placement and increased density.

Because shotcrete is projected at high velocity, it instantly compacts to reduce voids and form a dense, well-bonded layer.

Additionally, as it’s sprayed directly onto the surface, the concrete can bond to vertical, overhead, curved and hard-to-access areas.

This makes it suitable for structures where traditional poured concrete can be impractical, such as tunnels, retaining walls, pools, bridges, tanks, embankments and architectural features.

Shotcrete is used across civil construction, mining, infrastructure, water-retaining structures, repair works and architectural finishes.

Favoured for its flexibility, cost efficiency and strength, this method is especially suitable for projects where concrete needs to be applied to vertical, overhead, curved or irregular surfaces.

Common applications include:

• Retaining walls and piled wall facings: For stabilisation, reinforcement and long-term ground support.
• Tunnels, mines and underground works: For excavation support, linings and rock stabilisation.
• Slopes, embankments and channels: For erosion control, soil retention and surface protection.
• Dams, reservoirs, tanks and canals: For water-retaining linings and concrete protection.
• Bridges, wharves and civil structures: For concrete repair, strengthening and refurbishment.
• Pools, ponds and water features: For free-form shapes, curved walls and durable water-retaining structures.
• Architectural and free-form structures: For domes, climbing walls, sculptures, landscaping features and themed environments.
• Industrial protection works: For fire protection, refractory linings, pipeline encasement and protective coatings.

Shotcrete is a wet-mix concrete, whereby cement is mixed with aggregate and water before it reaches the hose.

This wet concrete is pumped to the nozzle, where high-pressure air projects it onto the surface at high velocity. From here, it’s applied in layers to build up the required thickness.

As the mix is prepared before spraying, shotcrete offers strong control over water-cement ratio, consistency, and strength. This makes it well-suited to larger projects where speed, volume and uniform quality are paramount.

For example, it’s often used for tunnels, retaining walls, swimming pools, tanks, civil infrastructure, slope stabilisation and structural repair.

This method generally produces less dust and rebound than dry-mix spraying. It can also be finished for structural or architectural purposes, although sharp details, tight returns and complex shapes require careful planning and skilled application.

Gunite works by feeding a dry blend of cement and aggregate into a spraying machine.

This dry mix is pushed through a hose using compressed air and then mixed with water at the nozzle immediately before it reaches the surface.

Once the mix hits the surface, the force of the spray compacts it into place. This helps create a dense, well-bonded layer on vertical, overhead or irregular areas.

The nozzle operator controls the amount of water added during application. Expertise is essential at this stage, as too little water can prevent proper compaction, while too much water can make the mix slump or lose strength.

This dry process gives operators precise control over placement, making it particularly helpful where the thickness, finish or shape demands careful management.

As a result, this method is typically used for repair work, smaller-volume projects, overhead surfaces, detailed shaping and sites with limited access.

Shotcrete and gunite can be applied to a wide range of prepared surfaces, including concrete, masonry, rock, soil, steel reinforcement and shaped formwork. It is often used on vertical, overhead, curved and uneven areas where poured concrete would be difficult to place.

For the best result, the surface needs to be clean, stable and properly prepared before spraying begins. Dust, loose material, oil, vegetation, standing water or weak concrete can reduce adhesion and affect the final result.

Some surfaces may also need reinforcement, mesh, anchors, or support systems to help the concrete hold its shape and meet the required structural performance.

Yes. Our experienced applicators are equipped to deliver projects across Australia and the Asia Pacific. Contact us today to discuss your requirements and organise gunite or shotcrete services.