Side-press for repetitive commercial work, down-press for string mops and simplicity, roller for flat and strip mops.

A side-press wringer uses a lever, so the operator pushes horizontally rather than bearing down. It is faster in repeated use and easier on the back, which is why it is the commercial default.

Down-press wringers squeeze evenly all round and handle heavy string mops well. They are simple, robust and cheap, and they require a downward push each time.

Roller wringers pull the mop between rollers and suit flat mops and strip mops that do not fit a conical wringer.

Match the wringer to the mop system already in use, because a mismatch means either poor wringing or damage to the mop head.

Wringer condition matters over time - worn pivots and cracked plastic reduce the pressure achieved, leaving floors wetter than they should be.

Enough that the floor dries within a short time - a floor that stays wet is a slip hazard and takes the area out of use.

Over-wet mopping is the commonest fault in floor cleaning. It leaves standing water, extends drying time, spreads soil rather than removing it, and creates a slip risk that is the leading cause of accidents in commercial premises.

It also damages floors: water penetrating joints in vinyl and wood, and lifting adhesives, is a slow and expensive failure.

A properly wrung mop leaves the floor damp rather than wet, and the surface should dry within a few minutes in normal conditions.

Wet floor signs are necessary but are not a substitute - they warn about a hazard that better technique would remove.

Where floors consistently stay wet, check the wringer's condition before retraining the staff; a worn wringer cannot produce a properly wrung mop.

Enough for a working area without refilling, but small enough to be moved and emptied easily - and small enough that changing the solution is not resisted.

The real constraint is that solution should be changed when it is dirty, not when it runs out. A very large bucket makes changing feel wasteful and staff push on with grey water.

Weight matters. A full large bucket is heavy to manoeuvre, difficult to lift to a sink, and a manual handling risk when emptying.

Mid-size buckets suit most commercial work: enough for a reasonable area, light enough to handle.

Where large areas are cleaned, the answer is usually a scrubber-dryer or a dual-chamber system rather than a bigger bucket.

Check the emptying arrangement. A moulded pouring lip or a drain plug makes emptying controlled; a plain rim means splashing and spills.

As soon as it is visibly soiled - typically every one or two rooms, and much more often in dirty areas.

A mop returns soil to the bucket every time it is rinsed. Once the water is grey, the mop is redistributing soil rather than removing it, and detergent has been consumed.

The visible test is reliable: if the solution is dirty, it is spreading dirt.

In washrooms, kitchens and clinical areas the interval is shorter, and cross-area reuse should not happen at all.

Changing frequently costs a little water and chemical and saves a great deal of appearance and hygiene, so the economics favour it strongly.

Dual-chamber buckets extend the interval by keeping clean solution separate from rinsed-out soil, which is precisely what they exist for.

Good castors, a rigid frame, a wringer with metal pivots, and a body that resists chemical and impact.

Castors fail first. Grit, hair and mop fibre wrap the axle and the castor seizes, at which point the bucket drags and scratches floors. Larger castors with sealed or serviceable bearings last much longer.

Frame rigidity determines whether a bucket survives being dragged, kicked and loaded. Flexing frames crack at the wringer mount.

Wringer mechanisms with metal pivots and replaceable parts outlast all-plastic assemblies, and being able to buy the wringer separately is a genuine advantage.

Body material should resist the chemicals in use - some plastics craze with repeated exposure to strong disinfectants.

Cleaning the bucket itself is the maintenance most often skipped. A bucket stored dirty and wet grows biofilm and smells, and that odour transfers to every floor it touches.

Yes wherever cross-contamination matters - washrooms, kitchens, clinical areas - and the scheme has to be documented and consistent.

Colour coding assigns equipment to areas so that a bucket used in a washroom is never used in a food preparation area.

The exact colour scheme is a matter of local convention and sector guidance rather than a universal standard, so what matters is that the site's scheme is written down, trained, and applied to buckets, mops, cloths and gloves alike.

It is particularly effective where staff do not all share a first language, since a colour needs no translation.

Storage should reinforce it - separate hooks or bays by colour, so a misplaced item is visible.

Auditing is simple and worth doing: a red mop in the kitchen store is an immediate and visible finding.

Emptied, rinsed, dried and inverted or stored open, off the floor where possible, in a ventilated store.

A bucket left with solution in it grows microbial contamination overnight and becomes a source rather than a tool.

Empty, rinse and allow to dry after every use. Inverting or storing on a rack lets residual water drain.

Mop heads should be removed, laundered or replaced, and dried separately - a wet mop left in a bucket is the classic source of the sour smell associated with poor cleaning.

The store itself needs ventilation and drainage. A sealed cupboard holding damp equipment produces exactly the odour the cleaning was supposed to prevent.

Keeping equipment off the floor makes the store cleanable and stops castors sitting in standing water.