The phrase in that question that decides the answer is not "steam" and not "vehicle". It is "bay". A workshop bay is a piece of infrastructure with its own constraints: a floor that may or may not fall to a channel, an inspection pit under the vehicle, a lift or jack post bolted into the slab, a water point and a drain that were installed for a different process, an electrical supply that runs past all of it, and an adjoining area where parts, tools and lubricants are handled. A high-temperature steam method can suit that place well, but the decision is settled by the bay and by the work carried out inside it, not by a figure on a machine brochure.
This article walks the confirmations in the order a buyer should make them: what the bay actually is, what is being cleaned and what must not be, what the site can provide where the work happens, what records have to be held for the exact equipment being considered, and how to run one bounded trial that answers the question in your building rather than someone else's.
Confirm what the bay is before confirming any machine
Two bays that look identical on a plan can behave completely differently once liquid is introduced. The variables that matter are structural and services ones, and every one of them is observable in ten minutes with a tape measure, a torch and a notepad.
Write these down for each bay you intend to work in. Floor finish and its condition: sealed or unsealed concrete, resin, painted coating, steel plate, existing cracks, joints, and whether the surface still has a profile or has been polished smooth by traffic. Fall and drainage: does the floor fall anywhere at all, is there a channel or gully, are the gratings removable, and is that drain connected to an interceptor or to a surface-water system. Pit and recess: an inspection pit, a sub-floor recess, a wheel-stop, a subsidence tray, and how deep they are relative to the working face. Lift and support equipment: two-post or four-post lifts, scissor platforms, jack stands, transmission jacks, trolley jacks, and the posts and arms that stand on the slab. Services at the point of work: water taps and their thread and fitting, the position and rating of socket outlets, cable runs and cable protection, lighting position, and extraction or ventilation if the bay is enclosed. Housekeeping fixtures: bins, parts washers, oil drums, chemical stores, tool cabinets and benches that sit within a couple of strides of the vehicle.
That list is not background detail. It determines whether a wet process can be run at all, how quickly a bay can be handed back dry, and whether a wheeled machine can physically reach and operate in the space. A bay with no fall and no drain can still be cleaned with heat, but the method changes and that change has to be confirmed and written down before the work is quoted.
Confirm which surfaces in the bay are actually in scope
A vehicle bay contains several cleaning objects that are usually lumped together. Separate them on paper, because the answer for one is not the answer for the next.
The built fabric: floor, wall bases, kerbs and thresholds, the face and edges of any pit, drainage channel and gratings, column and post bases, and the apron of floor immediately around the bay where fluid drips and re-soils. The fixed equipment: lift columns and arms, jack posts, wheel aligners, brake and tyre service equipment, oil drain units and funnels, parts washers, benches and cabinets. The vehicle itself when it is in the bay: exterior panels, sills, wheel arches, wheels, engine compartment, underbody and the interior. The shared surroundings: the adjoining store, the tool crib, the customer-facing area, and any space where food or drink is handled by staff.
The distinction matters commercially as well as technically. Cleaning the bay is a facility task on a schedule. Cleaning vehicles is a service sold to a customer, with its own process, its own insurance position and its own customer expectations. Confirming which of the two you are specifying stops a great many unworkable quotations, and it decides who owns each task afterwards.
Confirm the deposits, in the words your staff use
A bay collects a specific family of deposits: road film and brake dust on floors and wall bases; engine oil, gearbox oil and hydraulic fluid dropped during drain and refill work; grease smeared on hand-contact points, handles, wheel arch edges and bench tops; coolant and washer-fluid residue; tyre dust and rubber transfer on walls and sills; dust and fibre from brake and clutch work; and a general mixture of oil and grit where vehicles stand, which re-forms within a shift if the bay is worked hard.
For each surface row, note the deposit, how old it is, and whether it has been walked on or traffic-driven over. A fresh oil spill and a film that has been rebuilt by traffic for months are different jobs, even on the same floor. Note the surface material and its condition as well: which coatings are present, which areas have already lifted or patched, which labels and safety markings are printed on the floor or on equipment and whether their edges are already loose.
Confirm the exclusions before confirming the method
Damage in this kind of work almost always comes from liquid reaching somewhere it was not intended to, or from heat reaching something that was not meant to be heated. So the exclusion list is written first, and it stays part of the standard permanently with a replacement task against each line rather than a gap.
In a vehicle bay the usual exclusion rows are these. Brake friction surfaces, clutches and any friction lining. Wheel bearings, hub seals, CV boots and other sealing boots on the vehicle. Electrical connectors, instrument clusters, battery terminals, alternators and starter motors, fuse boxes, and the terminal boxes and cable entries on the bay's own equipment. Motor cooling fins, fans and vents on lift motors and on workshop machinery. Bearing faces, guideways and slideways on lifts and machinery that are not covered. Lubrication points and the lubricant held inside a gearbox or housing. Any decal, label or safety marking with a lifting edge. Paint that is already crazed, patched or re-coated, and filler or primer that has not fully cured. Bonded joints, adhesive trim and mouldings. Exhaust insulation and lagging. Floor coatings whose adhesion is already doubtful.
Against each excluded row write what is done instead: a dry wipe, a brush, a cloth dampened with a solvent the site has approved and recorded, a hand clean, or a visual check only, and state the trade-off the business accepts for that choice. Exclusions without a replacement are the reason a standard quietly stops being followed.
One more bay-specific point: heat and dwell affect some assembly work. Where a bay is also used for torque work, adhesive work, or work on components that are temperature sensitive, confirm the sequence with whoever signs the vehicle back out, because a cleaning pass and a repair are not interchangeable tasks in the same space.
Confirm the water, the run-off and the drain before anything else on services
This is the confirmation most often skipped, and it is the one that turns a reasonable plan into a compliance problem. Ask and record, bay by bay: where the clean water comes from, what the tap fitting actually is and what adapter is needed, whether the supply is potable and whether the connection arrangement is acceptable for the equipment being used. Where the dirty water goes. Whether the floor has any fall at all, and if not, how liquid is removed: absorbent, squeegee and collection tray, a wet collection machine if the site has one, or a mop-and-bucket routine that the standard has to name honestly. Whether there is an interceptor, silt trap or bunded collection point, whether it has capacity for this task, and who is contracted to empty and clean it. Whether any part of the run-off could reach a surface-water drain, a yard gully or a road, which is the failure mode to rule out on paper before work starts.
Then record what is in the run-off, in the site's own words: oil and grease, tyre and brake dust, grit, degreaser residue if any product is used. A bay that drains to an interceptor and a bay that drains to a surface-water system are two different jobs, and the second may require a low-moisture method with collection rather than a flushed one. This is a question for whoever holds the site's environmental permit or consent, not a decision for the cleaning supplier to make for you.
Confirm power, ventilation, access and the route the equipment travels
Power. Where the outlet actually is in relation to where the work happens, and how far cable has to run across a floor that may be wet. Cable protection in a wet bay is a written item, not an improvisation. If the process needs a supply that the bay does not have, that is a costed works item and belongs in the decision, not in a footnote.
A battery-fed unit shifts that question, and shifts it onto a different set of confirmations: how long a battery runs before the task is interrupted, how it is recharged, where it is recharged, whether a spare or a shift pattern covers the bay, and what the site provides at the point of work. Those rows are answered by records for the specific unit quoted, not assumed.
Air. A bay that is enclosed, below ground, or separated by shutters behaves differently from an open yard bay. Confirm what the space can exhaust, and whether a process that produces vapour and mist can be run in it while the bay remains occupied. If welding, fuel work or solvent work happens in the same space, confirm the sequence and who authorises it.
Access and route. Door widths and heights, internal corners, thresholds, kerbs, expansion joints, cable covers, gratings, ramps, lift posts and the tight turning space a bay is short of. For a wheeled machine those become a clearance check against the published dimensions of the exact unit, including handles. For a fixed machine the equivalent check is the working radius of hose and lance from one anchor point, and how far the operator has to work with the supply behind them.
Interruption. A bay is scheduled around vehicle movements. Every time the process stops to refill, to recharge, or to wait for a surface to dry, a lift is occupied and a job is late. Write the interruption profile down before choosing between a machine that carries its own supply and one that stands still and is fed from one point.
What to confirm about high-temperature steam itself
Steam earns its place in a bay for two things: lifting heated-and-reset oil and grease films, and reaching places a cloth cannot be pressed into, such as floor-to-wall junctions, the shoulders of kerbs and posts, channel edges, the base of lift columns and the lower band of cabinets and benches. It should not be relied on to clear a hazard by itself; the sequence is loose soil removed first, heat given time to act on the film, mechanical removal, then a dry finish. Skipping the mechanical step leaves the deposit smeared into a thin film that looks clean and re-soils within a day.
Two mode decisions have to be confirmed row by row, and neither is about which setting is "stronger". Low-moisture work suits warm surfaces, places near electrical equipment, and any row where you want heat dwell without sending liquid into a joint, a frame or a pit. Higher-moisture work suits thick built crusts on open faces where the liquid volume is what lifts the deposit and where the run-off has a route that the site has signed. On a bay floor with no fall, the low-moisture reading is usually the honest one, and that conclusion should be in the standard rather than left to the operator.
Two standing cautions about how equipment is described, worth carrying into every conversation with a supplier. A temperature published for the generator is not the temperature delivered where the lance meets your surface. A tank volume is not a working time. Both get quoted loosely, and both change what a bay cycle looks like.
A worked example of what a page actually publishes: the listing for Fixed Steam Cleaning Machine PowerDe HW02 shows a fixed floor-standing unit with dry- and wet-steam switching and a mains tap-water inlet, and it positions that machine around vehicle exterior cleaning at fuelling and parking sites, interior work and engine-compartment cleaning. It does not publish a workshop-bay application, a bay cycle time or a floor-cleaning rate. Treat that scope as what the page says, and treat anything outside it as a question for the supplier rather than a claim to reuse in your paperwork.
The records to confirm in writing for the exact unit you are quoted
Ask for these as rows, for the specific machine on the quotation, and decline an answer that points at a brochure or a range. A figure that does not name its unit and its condition is not evidence.
Temperature and vapour pressure as delivered at the lance under load, not at the generator. Heating power and working voltage, read against the outlet that exists in your bay and the cable protection you would need. Water inlet fitting and what adapter is supplied, checked against your tap. Tank capacity and hourly water use as two separate rows, because they answer different questions. For a battery-fed unit, battery figure, run time, charging time and how depletion is handled across a shift. Dimensions and weight, and the travel route against your doorways, thresholds, channels and turning space. Hose and lance reach, measured against your reachability list. The protective features present on that unit, listed by name rather than counted, plus what each one does and does not cover. Whether an extraction or recovery function exists at all on that unit, since it appears on some machines in a range and not others. Which consumables the unit needs, at what interval, and at what cost per bay. And how a trial is arranged: what the supplier brings, and what the site has to provide.
If your bays turn out to need a configuration the range does not publish, the built-to-order route is the service listed as customized steam cleaning equipment, where your bay sheet and your records, not a catalogue, drive the specification. The range itself sits under PowerDe cleaning equipment.
Confirm the bay's own rules: permits, waste, safety and sign-off
Before the trial, not after it, confirm the paperwork the site already carries. What consent or permit governs what may enter the drain, and what it says about oily run-off and about cleaning agents. How the collected liquid and the wipes and absorbent used in the process are classified and stored, and which contractor removes them. Which product, if any, is approved for use, at what dilution, with what data sheet held and what training recorded. Slip risk while a bay is wet, barrier and signage arrangements, and who keeps the bay out of service until the dry condition is met. Whether the work touches the vehicle or the customer's property, and how that is covered. Who signs the bay back into service, and what the dry condition actually is: no standing liquid in a joint or channel, no pooled liquid at a post base or pit edge, no wet label, and a visual check of internal corners and the apron.
Run one bounded trial in one bay and let it settle the question
Do not decide from a demonstration at a trade show or a video. Decide on one bay you choose for its awkwardness, not for its ease.
Mark a small set of rows with tape: one open floor area with traffic-built film, one internal corner or junction between floor and wall base, one fixed-equipment surface with a grease deposit such as a lift post base or an oil drain unit, and one awkward interface such as a channel edge, grating frame or threshold. Photograph each row as it stands, from an angle that shows the deposit, before any liquid is applied.
Write the stop conditions on paper before the first pass: floor coating lifting or blistering, a label or marking edge lifting, liquid reaching an excluded row or an unguarded drain, a surface dulled or hazed, a treated area remaining slippery. When a stop condition is met, that row stops, moves to the exclusion column with its replacement, and the rest of the trial continues.
Time the work in named blocks rather than one total: isolating and clearing the bay, shielding and protection, travel and set-up, the pass itself, refilling or battery handling, drying and recheck, restoring the bay and handing it back. Run the same rows twice from the same starting condition and take your figure from the second run. Inspect the same rows at the end of the next working day: a bay floor that is re-filmed by traffic by close of business tells you the interval is wrong, not the method. Acceptance is the before photograph and the next-day photograph side by side, and the acceptance standard is written before the trial begins.
Turn the confirmed answers into a bay standard
One page per bay type, one row per surface, with columns for deposit, mode, shielding, run-off route, dry closing condition, owner and sign-off. Keep the exclusions and their replacements on the same page. Train the page in the bay with the people who will run it, at the actual surfaces, so they can explain why a seal or a friction surface is on the exclusion list rather than merely knowing that it is.
Give every row a defect route: what happens when a surface does not come clean, who is told, and what gets recorded. Put a review date on the page, and name the changes that force an earlier review: a new bay or a re-coated floor, a change of drain route or interceptor, a change of lubricant or process fluid, a new lift or item of equipment, a change of shift pattern, and any month in which the cycle stops matching its own block times.
Signs the confirmation has not really been done
A handful of quick checks on your own process. If nobody can point to a written run-off route for the bay, it has not been confirmed. If the exclusion list has no replacement column, it will not survive contact with a busy week. If there are no before photographs, acceptance was an opinion. If the supplier's answers do not name the exact unit, they are not answers. If the trial had one cycle time and no named blocks, the interruption cost is invisible, and it is the interruption cost that makes bay work fail. If the bay's dry-off, waste and drain arrangements were decided by the cleaning operative on the day, the confirmations were never made at all.
Work through them in this order and the question stops being a matter of opinion. The bay, the surfaces, the exclusions, the drain, the services, the records for one named machine, then one trial in one bay. That sequence also produces the document a supplier needs in order to quote sensibly, which is the difference between buying a machine and solving a cleaning problem.
