What is brush pressure on a floor scrubber?

Rotation alone does not clean

A scrubbing brush removes soil by dragging bristle tips across the floor under load. Take the load away and the same brush at the same speed does almost nothing: it planes over the top of the soil film, wets it and moves on. Brush pressure is the specification that describes that load — the downforce the machine puts through the disc, measured in kilograms and listed on POLIVAC and Mitchell scrubbers alongside brush speed and cleaning width.

The figures across the catalogue show how wide the band is. The battery GB380D mini scrubber applies 6 kg through a 430 mm path. The Mitchell COLT walk-behind applies 30 kg through 508 mm. The Mitchell Brumby ride-on applies 40 kg through 560 mm. The burnishers quote the same idea as pad pressure — 10 kg on the SL1600, SL2000 and Gas 38, 12 kg on the Stealth — because at burnishing speed contact force is what controls the finish.

Where the weight comes from

On most walk-behind and ride-on scrubbers the pressure comes from machine mass sitting on the deck, which is why a heavier machine usually scrubs harder — the Brumby weighs 220 kg, the COLT 170 kg. On single-disc polishers and scrubbers it is the machine weight over the pad that does the work, and POLIVAC adds ballast deliberately on the sanders: both the SV25 and SV30 SuperVac are fitted with extra weight to increase downward pressure for improved results.

This is also why brush pressure has to be read together with speed and path width, never on its own. High pressure at low speed cuts; high pressure at high speed burns. A wide path at low pressure covers ground and leaves the film behind.

When it matters

Compare brush pressure when two scrubbers have the same cleaning width and one is cheaper. It is one of the few specifications that predicts whether a machine will actually shift built-up soil, greasy kitchen floors or heavy traffic marking, rather than just wet them and pick the water back up.

More is not automatically better. Pressure costs battery: every extra kilogram on the deck is current drawn from the same charge, so a high-pressure machine on a long run may not finish the shift. On a sealed or polished floor, too much pressure with the wrong pad cuts into the finish you are trying to preserve, which is a re-coat you did not budget for. Light-soil maintenance on a good floor wants coverage, not force.

The mistake to avoid is comparing a quoted pressure across machines that measure it differently — some figures include the brush and deck, some do not, and pad pressure on a burnisher is not the same thing as brush pressure on a scrubber. If the decision is close, ask for the figure in writing against a named pad or brush.