School and Hospital Entrances: Managing the Twenty Metres That Decide Whether Someone Falls
Author: SIBEN Publish Time: 2026-10-30 Origin: Site
Twenty metres is not a marketing figure. It is the distance a wet sole travels before it either reaches a dry surface or loses grip: about eight metres of approach outside, the threshold itself, and up to ten metres inside before the floor dries or the person slows down. Everything in this guide happens inside that strip.
The twenty metres in numbers
Risk strip = 8 m outside + threshold + 10 m inside
Mat length ≥ 3 paces (1.8–2.5 m); ≥ 3 m at main entrances
Sign placed before the wet area, never inside it
De-icer: GB/T 23851-2017 conformity + CMA report
1. Why the Entrance, Not the Corridor, Is the Risk Point
Falls rarely happen at the centre of a doorway. They happen five to eight metres outside and three to ten metres inside, where people close umbrellas, check phones, fold pushchairs or push wheelchairs. Attention is lowest and soles are wettest exactly there. A corridor that looks clean all day can still fail at its first ten metres.
Treat that strip as one line with one owner, not as one mat with one cleaner. When the strip is split between an outdoor contractor, an entrance attendant and a floor team, the handover points are where the water stops being anyone's job.
2. Three Zones, One Job Each
The chain has three links. Each link has exactly one job, and each has a characteristic failure. Naming the failure is what makes an inspection possible.
| Zone | Extent | One job | Fails when | Owner |
|---|---|---|---|---|
| Remove (outdoor) | 8 m outside to the threshold | Take water away before it is carried in | Wet leaves, blocked gully, canopy drip, refrozen meltwater | Maintenance + cleaner |
| Absorb (transition) | Threshold ± 2 m, mat field | Remove residual water from soles | Mat shorter than three paces, single layer, sliding, saturated | Cleaner |
| Warn & dry (indoor) | 10 m inside | Warn, divert and dry the remaining film | Sign behind a corner, floor mopped to a film, peak unstaffed | Supervisor + mobile post |
A chain fails at its weakest link, and the weakest link is usually the one nobody was assigned. In practice that is the transition zone: too wide for the outdoor sweeper, too far from the indoor mop.
3. Remove: Keep Water Outside
Wet leaves are a slip hazard, not landscaping. In rain, frost and snow, sweep by fall rate rather than by a fixed schedule, adding frequency at doorways, ramps and wind-exposed corners. A fixed twice-a-day round is written for dry weather and quietly fails on the first wet morning.
Keep a puddle map
Record where water appears every day: canopy outlets, blocked gullies, damaged paving, a low point where the fall is wrong. The same puddle returns in the same place, and habit makes it invisible. Once it is on a drawing with a date, it becomes a work order instead of weather.
Umbrella stands belong outside
An umbrella stand inside the lobby means every visitor crosses the entire mat field with a dripping umbrella. Put it outside the transition zone, with a drain path that does not run back toward the door.
Clear before the doors open
Removal is a pre-opening task, not a during-service task. Snow cleared at 08:40 for a 09:00 clinic start has already been walked into the building for twenty minutes.
4. Absorb: Four Questions About Mats
Most mat failures are not about material quality. They are about length, layering, stability and rotation — four questions that can be answered on site in under five minutes.
| Question | Test on site | Target | Common failure |
|---|---|---|---|
| 1. Long enough? | Walk it in normal paces | ≥ 3 paces (1.8–2.5 m); ≥ 3 m at busy main entrances | A single 1.2 m mat — the most common failure on site |
| 2. Layered? | Two distinct surfaces | Outer scraping surface + inner absorbent one | One thin mat that spreads mud instead of removing it |
| 3. Stable? | Kick the edge, watch the backing | No slide, no curl, fully dry before reinstating | A curled edge becomes a trip edge; a wet mat is worse than none |
| 4. Rotated? | Ask who, and when | Swap on saturation in snow; keep one set drying | No owner, so the mat stays wet from morning to noon |
Mat width matters too: a mat narrower than the clear opening leaves a bare strip at each jamb, and that strip is exactly where people cut the corner. Cover the full opening, and never cover a threshold plate or tactile paving that carries a function.
5. Warn: Why a Sign Is Not a Defence
Two judgments reported on 28 October 2026 are instructive. In the first, a court found standing water at a garage entrance, no sweeping and no mat, a warning sign placed at the foot of a slope behind a corner where it was easily missed, and no staff present at peak time. The operator was held 50 per cent liable; the injured party's own failure to slow down accounted for the remainder. The judge's reasoning was widely quoted: safety is a substantive duty, and posting a notice does not discharge it. A second judgment published the same day produced 70 per cent. Both are individual decisions, not a rule.
Put the sign in the line of travel before the wet area.
Clear the water or barricade at the same time — a sign alone is a claim, not an action.
Staff predictable peaks to warn, divert and steady people, not to sweep.
Never place a sign mid-slope where a person has already committed to the path.
Warn is the cheapest link and the easiest to fake. A sign photographed at 09:00 proves a sign existed, not that anyone saw it or that the floor was dry.
6. Dry: The Wet-Mopping Trap
Repeated wet mopping in rain leaves a continuous film and makes the floor more slippery than before the mop arrived. The sequence matters more than the product: remove mud and slush with dry tools first, mop one way in sections, keep a dry lane open, and collect water at once with a squeegee or scrubber-dryer.
| Wrong order | Why it fails | Correct order |
|---|---|---|
| Mop first, collect later | Mud is spread over ten metres before it is removed | Dry removal → one-way mop → immediate wet pickup |
| Mop the whole entrance in one pass | No dry route exists while the floor is wet | Half-width sections, alternate sides |
| Two mops, no squeegee | Water is moved, not removed | Squeegee or scrubber-dryer with a working pickup |
If streaks appear under side light after scrubbing, inspect the squeegee blade first: wear and nicks are the usual cause, followed by a full recovery tank and a blocked pickup. A blade changed on schedule prevents more streaks than a stronger chemical.
7. Freeze: De-Icer Can Make Tomorrow Worse
De-icer melts snow into water that may refreeze as black ice overnight, and chloride salts attack door frames, floor springs, mat edging and machine housings. Clear mechanically first and treat only residual ice — spreading salt on fresh snow buys a wet afternoon and an icy morning.
Verify before you buy
| Check | Ask for | Why it matters |
|---|---|---|
| Standard conformity | GB/T 23851-2017 test report | Baseline for procurement and audit |
| Freezing point | CMA third-party report | Wrong melting point means refreeze at night |
| Corrosion rate | Steel, aluminium, concrete data | Protects frames, springs, mat edging, housings |
| Friction loss | Post-treatment friction test | Some products leave a slippery residue |
| Heavy metals | Report limits | Discharge and soil limits; indoor residue |
After snow, rinse and dry the indoor zone more often than usual, and drain and dry tanks before cold storage. Salt carried indoors stays tacky on tile and keeps collecting dirt long after the snow has gone.
8. Schools and Hospitals: Same Strip, Different Clock
The physical method is identical. What differs is who walks through it and when, and that difference decides the schedule.
| Dimension | School | Hospital |
|---|---|---|
| Peak clock | Ten-minute break, lunch, dismissal, first 30 minutes of rain or snow | Before clinics open, both clinic peaks, visiting hours |
| People | Running, crowding, wet umbrellas at the gate | Wheelchairs, trolleys, visitors who do not know the layout |
| Hot spots | Gate, canteen ramp, stair corners, covered walkways | Entrance ramp, clinic queue, lift lobby, emergency route |
| Rule | Finish remove and absorb before the bell | Never block a continuous dry route; no sign mid-slope |
In a school, the risk is speed and crowding in a ten-minute window; the whole job must be finished before the bell, not started at it. In a hospital, the risk is a person with impaired balance meeting an unfamiliar surface, so a detour is not a solution — the dry route must stay open end to end.
School entrance rule
Remove and absorb finished before the bell. Ten minutes is the whole window; there is no second chance until lunch.
Hospital entrance rule
A continuous dry route stays open at every hour, including during visiting time. Signs warn, they never block.
9. Record: Five Fields and Three Sentences
A record that cannot answer "what did you do, when, and who checked it" is a diary, not evidence. Five fields are enough.
| Field | Content | Why it matters |
|---|---|---|
| Time & weather | Timestamp, temperature, precipitation type | Establishes the condition that actually existed |
| Water source | Canopy outlet, gully, paving, carried-in | Points to the fix, not just the mop |
| Action & time | Swept, matted, mopped, barricaded — with times | Shows the chain was executed in order |
| Verification | Who checked, how (dry-hand test, side light) | Separates "done" from "checked" |
| Signature & recheck | Two signatures; recheck time on any failure | Makes the record contestable and complete |
Three contract sentences
Scope: eight metres outside, the threshold, and ten metres inside, including mat rotation.
Standard: no continuous water film during snow and for 48 hours after.
Closure: a recorded recheck, a fee deduction if the same point fails again, and liability allocation if harm occurs.
Wording such as "ensure safety" or "keep the floor clean" is almost impossible to evidence in a dispute. "No continuous water film at the main entrance between 07:00 and 09:00, verified by hand test and photographed" is not.
10. Four Roles Across Twenty Metres
| Role | Owns | Fails when unassigned |
|---|---|---|
| Cleaner | Remove, absorb, mop one way | Water is pushed inward and spread |
| Mobile post | Warn, assist, divert at peaks | The peak is unattended and the sign is ignored |
| Maintenance | Drip points, gullies, thresholds, mat edging, entrance lighting | The same puddle every day; water invisible in the dark |
| Supervisor | Sign-off, recheck, staged opening | A record without verification, and an all-or-nothing opening |
Lighting is part of the strip. A wet floor at 07:20 in December cannot be seen by a person coming in from a bright street; if the entrance lighting is on a timer, the timer decides whether the water is visible.
Frequently Asked Questions
How long should an entrance mat be?
At least three normal paces, about 1.8 to 2.5 metres, and three metres or more at busy main entrances. A single 1.2-metre mat is the most common failure on site.
Is a caution sign enough?
No. Courts look at whether water was cleared, mats laid, the sign visible, and peaks staffed. A notice does not discharge a substantive duty.
Where should the sign stand?
In the line of sight before the wet area, never inside it, after a turn or mid-slope.
Why does mopping make it worse?
Mud is spread and a film remains. Remove debris dry, mop one way, and collect water at once.
Streaks remain after the scrubber-dryer. Why?
Usually a worn or nicked squeegee blade, a full recovery tank or a blocked pickup.
Does de-icer increase slip risk?
It can, by melting snow into water that refreezes, and salt carried indoors stays tacky.
What should we check when buying de-icer?
Conformity to GB/T 23851-2017 plus a CMA report covering freezing point, corrosion rate, friction loss and heavy metals.
Can a dry vacuum pick up slush?
No. Water damages motors and filters; use wet pickup, then drain and dry the tank.
What differs between schools and hospitals?
Schools manage running and break times; hospitals manage wheelchairs and clinic peaks without blocking a dry route.
What belongs in the inspection record?
Weather and time, water source, actions with times, verification method, two signatures and a recheck time.
