A machine shop floor clean is usually planned around a shutdown, a weekend, or a slow shift, and the first question whoever plans it faces is how long the job will take. Estimates usually fail for the same reason: the person making them counts the time the wand is moving and ignores everything else. Clearing the area, protecting equipment, letting heat work on the deposit, collecting runoff, refilling the tank, drying the concrete, and reopening the aisle all consume time, and on most floors those phases add up to more than the cleaning passes themselves. A usable estimate comes from breaking the job into those phases, measuring them on your own floor, and adding up what you saw.
The framework below works for any method: steam, hot water, a pressure washer with degreaser, or a scrubber. Where it helps to read a datasheet, the PowerDe HW02 fixed steam cleaning machine is used as the example, because its published parameters show exactly which numbers a datasheet gives you and which ones you still have to ask for.
Why the estimate goes wrong before it starts
Three errors account for most of the schedule surprises on floor jobs:
- Estimating from total floor area. The drawing gives one number; the crew can actually clean the aisles, the machine perimeters, and the stained patches. Racking, machine footprints, and fixed equipment remove area from the calculation and add handling time to it.
- Counting only spray time. Crews who do this work regularly will tell you that preparation, protection, and drying dominate a typical shift, not the passes themselves.
- Assuming one pass is enough. A fresh coolant film lifts in a single pass. Polymerised deposits need dwell time and repeat passes, so the estimate has to reflect the worst deposit you plan to treat, not the easiest one you happened to look at.
The phases that consume the time
Write the estimate as a list of phases rather than one number. For a steam or hot-water floor job there are six:
- Clear and protect. Move pallets, jigs, and loose equipment; cover floor-mounted cabinets, cable runs, conduit penetrations, and open panels; lift drain baskets. This time scales with the number of items, not the square metres, so count the items during your walk-through.
- Dry removal. Sweep or vacuum loose swarf, scrape heavy deposits, absorb standing oil. Skipping this phase does not save time; it moves the time into the cleaning passes and re-deposits grit on the floor you just cleaned.
- Set-up and test patch. Route the hose from wherever the machine will stand, check reach to the farthest point, let the machine reach working conditions, and photograph a small test patch. A few minutes here prevents a redo across the whole room later.
- Cleaning passes. Heat releases oil, and the wand has to move slowly enough for that heat to stay in contact with the deposit. The heavier the deposit, the slower the pass. Dry steam suits areas near electrical equipment; wet steam suits heavier deposits that need the heat to soak in.
- Runoff recovery. Squeegee the emulsified oil toward a collection point before it dries, or it re-deposits as the floor dries. Add any refill breaks that the tank size and the distance to the water point force.
- Drying and release. The floor stays closed until someone has checked grip. Drying time depends on ventilation, floor temperature, and how much moisture the method left behind. Measure it; do not assume it.
What changes the duration of each phase
Before measuring anything, note the conditions that will stretch or shorten the job. For machine shop grease removal in particular, five conditions decide the schedule:
- Deposit state. Fresh oil film, polymerised grease, and oil bound with grinding swarf behave differently. The first responds quickly to heat. The second needs dwell and repeat passes. The third needs mechanical removal before any liquid method touches it. Estimate against the state you will actually find, which means looking at the worst patch, not the average one.
- Obstacle density. Two floors of identical size can differ by hours. Measure cleanable area zone by zone: main aisles, machine perimeters, leak points under valves and ways. Estimate each zone separately and add the zone totals.
- Distance from the fixed point. With a fixed machine, hose length and the refill radius decide how much of the job is walking. Measure from the planned machine position to the farthest point you intend to clean, and from that position to the water point.
- Crew size. One operator alone does spraying, squeegeeing, and refilling in sequence. Two people, one on the wand and one on the squeegee, change the arithmetic completely. State the crew size in the estimate, because the same floor takes different times under each arrangement.
- Working window. A cold early-morning floor dries slower. Night work may mean quieter methods, interrupted access, or a crew that is tired. A job that fits comfortably inside a Saturday shutdown may not fit a Tuesday night.
What the datasheet tells you about time, and what it does not
Equipment parameters affect specific phases of the list above. Read them for that purpose, using the HW02 datasheet as the worked example:
- Working temperature and pressure (listed as 160 °C and 0.8 MPa) indicate how fast heat reaches the deposit, which influences pass speed and dwell. They do not state square metres per hour, and no datasheet can: that number belongs to your floor, not to the machine.
- Heating power and tank capacity (listed as 6 kW and an 80 L SUS304 tank with a tap-water inlet) shape the work cycle: how long the crew cleans before a refill, and how long the machine needs between refills. The sheet does not publish steam runtime per fill, so ask for that figure and the flow rate in writing before you schedule refill breaks.
- Machine size (listed as 1,200 × 800 × 1,200 mm including handles) belongs in the move-in and repositioning time, and in the check that the route to the machine position is actually clear.
- Protection functions (leakage, short-circuit, high-temperature, high-voltage, and water-shortage protection are listed) protect the machine. They do not protect your schedule; the crew still plans around interruptions they may cause.
- One caution. The HW02 product page describes vehicle cleaning uses. For floor work, confirm floor tools and suitability with the manufacturer before treating these numbers as a floor estimate.
Measure a pilot instead of guessing
The only reliable numbers are ones you take yourself. Whether you are trialling an industrial maintenance steam cleaning machine or a pressure washer you already own, a short pilot produces them:
- Mark a representative strip: one straight aisle, one machine perimeter, and one realistically stained patch. Photograph the boundaries so the pilot can be repeated.
- Run the full sequence, protect, dry removal, clean, squeegee, exactly as the real job would run it.
- Time each phase separately with a phone stopwatch. Count the passes and note how long the heat needed to sit on the deposit before it lifted.
- Measure how long the strip takes to pass a grip check under your normal after-hours ventilation.
- Extrapolate each zone type from the matching part of the strip, then add time for the refill breaks, protection items, and corners your strip did not include.
- Write the numbers down. That record is your estimate, and it doubles as the acceptance baseline for the real job.
A one-page time estimate
Put the result in a form your team and your equipment supplier can both read. One sheet, one row per phase:
| Phase | What to measure | Where the number comes from |
|---|---|---|
| Clear and protect | Count of items to move and cover | Pre-job walk-through list |
| Dry removal | Time per zone for sweeping, scraping, absorbing | Timed pilot |
| Set-up and test | Hose routing, reach check, warm-up | Timed pilot |
| Cleaning passes | Minutes per zone type, pass count, dwell | Timed pilot, matched to the deposit state found |
| Runoff and refills | Squeegee time plus refill breaks | Pilot plus the supplier's runtime per fill |
| Drying and release | Time to a verified grip check | Pilot under real after-hours ventilation |
| Total | Sum of the rows plus contingency for missed corners | Your own records, reviewed by the supplier |
When to re-estimate
The sheet has a shelf life. Re-run the pilot and update it when:
- Coolant chemistry or swarf load changes, so deposits behave differently on the same floor.
- Machines, racking, or flow paths move, changing obstacle density and fixed-point reach.
- The season turns and floors start cold, which slows both cleaning and drying.
- The method changes, steam replacing a pressure washer, or a scrubber replacing manual work.
Each of these invalidates the old numbers. Re-run the pilot on the worst zone and update the sheet before the next planned clean, not after the schedule has already slipped.
The estimate is a record, not a guess
A credible time estimate is not a guess dressed up as a number. It is the sum of phases you listed, measured on your own floor, with the conditions that stretch each phase written next to the figure. Do that and two things happen: your team gets a plan it believes, and your equipment supplier can look at the same sheet and tell you what you have missed, whether that is a drain route, a dedicated circuit, or a floor tool you did not think to ask about. If you want a second pair of eyes on your floor layout and cleaning window before choosing a machine, send your zone list and pilot record through PowerDe's contact page.
