Concrete spraying and plastering: how much compressor air?

The unit also varies. Litres per minute, cubic metres per minute, cfm and cubic metres per hour all appear in the catalogue, so always compare in the unit your compressor is marked with.

The rotor machines: the compressor stands alongside

Aliva states the recommended compressor for each rotor size, and separately for dry-mix and wet-mix spraying. The pattern is clear: a larger rotor moves more material and needs more air, and wet-mix spraying is given higher figures than dry-mix spraying on the same rotor.

Note the unit: the dry-mix values are given in both m³/min and cfm. In the data sheets, the wet-mix values are given as 11.2 and 15 “m³/h” alongside 400 and 525 cfm, but cfm is cubic feet per minute, and 400 cfm is roughly 11.3 m³ per minute. So go by the cfm figure.

• Aliva-237 with S rotor — 3 m³/min (105 cfm)
• Aliva-257 with M or L rotor — 7.2 m³/min (255 cfm) dry, 400 cfm wet
• Aliva-257 with XL rotor — 10 m³/min (350 cfm) dry, 525 cfm wet

The plastering machines: the compressor is built into the machine

On most plastering machines the compressor is built in, so the air requirement has been taken care of by the manufacturer. Even so, the figures say something about how much the machines differ:

• T7 EVO — 210 l/min, as an option
• Giotto Mono — 210 l/min
• Mini Avant — 220 l/min, in all versions
• Giotto — 250 l/min
• Uni 30 — 270 l/min
• T20X and Pro DM — 400 l/min, 7 bar
• POLI T — the compressor is optional: built-in at 230 l/min (1.1 kW) or 283 l/min (1.5 kW), or a separate three-phase compressor of 592 l/min, 3 kW and 400 V for thin-coat plaster. The separate compressor must be included in the power supply planning in the same way as the pump

When the air does the conveying

Apemat and Transmat shoot the levelling compound through the hose with compressed air. The air requirement is then on a completely different scale, and a compressor that is big enough for plastering is not big enough here:

• Apemat — site compressor of 2 400–5 000 l/min at 6 bar, which is not included
• Transmat 250 — site compressor of at least 3 600 l/min at 6 bar (3 600–5 000 l/min in the data sheet from 2025), which is not included either
• Transmat 27.45 — built-in compressor of 4 500 l/min at 6 bar, so no external one is needed

Spraying pump and spraying rig

On a spraying pump, it is the pistons that move the concrete, and the air is used for the spraying. For the Aliva-272, the required air pressure for spraying is given as approx. 7 bar.

The Dragon spraying rig can be supplied with its own compressor on request, with an air flow of 6 500 l/min, driven by a 37 kW electric motor. The rig weighs 5 300 kg without the compressor and 6 600 kg with it. In other words, the compressor is a significant part of the machine.

Silo conveying: per hour, not per minute

Silotur, which blows dry mortar from the silo to the plastering machine, states the air flow per hour: 100 or 140 m³/h, with a max. pressure of 2.6 bar. Most other machines in the catalogue state air per minute, and the figures are easy to misread when they are side by side.

Pressure and air flow are not the same thing

The pressure in bar tells you how hard the compressor pushes. The air flow tells you how much air it delivers per minute or per hour. A compressor can reach the required pressure and still deliver too little air to keep up with the machine.

That is why Turbosol states the air flow “at 6 bar” for Apemat and Transmat. It is the air flow at that pressure you should compare against, not the largest figure on the compressor's rating plate.

When you contact us

Tell us which machine the compressor will be used with — and the rotor size if it is an Aliva — whether you will be spraying dry-mix or wet-mix, and what air flow and pressure your current compressor is marked with. A photo of the rating plate is often the quickest.