The method · In full

Everything the drawings
could not fit.

The interactive sections on the front page show why the method exists. This page covers how it is actually run, what decides between the two approaches, and where its limits are.

What it is
Concrete placed pneumatically, not poured. A method, not a material.
Two approaches
Wet mix and dry mix differ in where water is added.
Decided by
Access, volume, the surface, and site conditions.
Unchanged by it
Reinforcement, thickness, cover, mix design and testing.
This page is not
Engineering advice, a specification, or a performance guarantee.

Drawing 05

Where the water goes in.

That single difference is what separates the two approaches, and it changes who is controlling the mix and where.

Drawing 05 — wet mix and dry mix compared
Schematic · not equipment specific
Wet mix Water added at the plant
Schematic of wet mix shotcrete: concrete is batched with water, pumped along the hose, and air is added at the nozzle. MIXED WITH WATER HERE PUMPED ALONG THE HOSE, ALREADY WET AIR NOZZLE CONTROL SITS UPSTREAM, AT THE PLANT

What that means on site

Consistency is measurable

The mix is proportioned before it ever reaches the hose, so what leaves the nozzle is what was batched. Usually the choice for larger, continuous volumes.

Dry mix Water added at the nozzle
Schematic of dry mix shotcrete: dry material is conveyed along the hose and water is introduced at the nozzle by the operator. DRY MATERIAL NO WATER YET CONVEYED DRY, ON AIR WATER NOZZLE CONTROL SITS AT THE FACE, IN A PERSON’S HANDS

What that means on site

The operator is the control

Water is judged continuously at the nozzle, so the finished work depends heavily on the person holding it. Often suits repairs, stop-start work and awkward access.

Read this

Neither is the better method in the abstract. The choice depends on access, volume, the surface and site conditions. Discuss the proposed placement method and equipment with Rosales when reviewing your project.

The real questions

What actually decides
the approach.

None of these are answered by a website. They are answered by looking at the place.

01

Can equipment reach it?

Hose length, where the pump stands, whether a truck can get near the face. Access changes the method more often than the shape does.

02

What is the face made of?

Rock, soil, sound concrete, failing concrete. It decides the preparation, how reinforcement is anchored, and whether anything bonds at all.

03

Where does the water go?

Behind a facing, water has to be given a route out. Sealing a face without thinking about drainage is how work fails a few winters later.

Limits

What the method
does not do.

Worth stating plainly, because the enthusiasm around it usually is not.

  • It is not stronger for being sprayed. Strength comes from the mix, the reinforcement and the compaction — not from the delivery.
  • It does not replace engineering. Anything retaining earth or carrying load needs a design. We place concrete; we do not design your structure.
  • Poured concrete is part of our work, too. We also plan driveways, sidewalks, porches and patios using conventional concrete placement. The project and site determine the method.
  • It does not fix a face that is still moving. If the ground behind it is failing, a facing will crack with it. The cause comes first.
  • It is not waterproofing. Watertightness comes from thickness, cover, compaction and finish, plus whatever the project specifies.
  • It is not tidy. Overspray and rebound have to be cleared. That is part of the job and should be part of the scope.

From the method to your project

These diagrams explain general shotcrete principles. Discuss the proposed equipment, placement method and project requirements with Rosales before work begins.

Describe your site Back to the design studio