At half past eight on a Monday morning a photo lands in the property management group: high on a tower facade, one pane has cracked into a spider web. The emergency call has been made, the response crew says the day after tomorrow at the earliest. The glass is still seated in its frame, the pavement below carries its usual traffic – and for the next few days, nobody is quite sure what to do.
In fact, the stretch between the breakage and the replacement is often the riskiest and the most mishandled part of the whole event. Why glass breaks on its own was covered earlier, and the full chain from order to acceptance for a panel swap has been walked through step by step. This article deals only with the days in between: what temporary protection is actually preventing, who does what, and where the line of due care sits.
1. The call has been made, and the glass is still in the frame
1.1 Why the replacement is certain to take time
Curtain wall glass is not a shelf item: the opening must be measured, the panel ordered and scheduled, then the gondola and a weather window awaited. Even a modest single tempered pane does not arrive the same day – the replacement chain has been broken down before, and here it is accepted as a premise: the waiting period is structural, not a delay the manager chose.
1.2 During these days the risk does not pause
The trouble is that the waiting period is not a safe period. The damaged pane still carries three loads: its own weight, wind vibration and the day-night temperature swing. Its strength is already gone, and one loosened edge means a secondary fall – statistically, the risk of something coming down in these days is not lower than at the moment of breakage. Granules keep shedding too, landing on canopies and ledges below.
2. Identify the type first: monolithic tempered, laminated and insulating glass break differently
2.1 Why tempered glass breaks into granules
Under GB 15763.2-2005, Safety Glass in Building – Part 2: Tempered Glass, tempered panes of 4 to 12 mm nominal thickness must fragment so that any 50 mm by 50 mm area holds at least 40 particles, with elongated shards no longer than 75 mm and no knife-like ends. The design exists so the fragments cannot cut; the price is that they keep falling. A spider-web pattern plus shedding granules points to monolithic tempered glass.
2.2 Laminated glass holds together – that does not mean leave it alone
Under GB 15763.3-2009, the interlayer holds the fragments of laminated glass, and most panes stay seated in the frame. But held together is not the same as safe: the full weight of the pane still hangs on the setting blocks, and edge spalling or a whole-panel drop both remain possible. A dense crack pattern with no falling granules deserves the same urgency, not less.
2.3 Insulating units: an outer pane and an inner pane fall in opposite directions
In an insulating unit each lite fails its own way: a broken outer lite sheds toward the street and threatens people below; a broken inner lite sheds into the room and threatens the occupants. Decide which lite has failed before anything else – the direction of the cordon depends on it. This step is the one most often skipped in public procedures, yet it sets the direction for everything that follows.
3. In the official procedure, step one is never replacement
3.1 The nine steps of Qingpu: report, protect the site, then seal and brace
The glass curtain wall emergency reporting procedure published by Qingpu District runs nine steps: identify the danger; report by phone, stating the building, the address, the location and the site conditions; emergency protection of the scene with a dedicated watcher to prevent secondary injury; emergency measures within reach – sealing, blocking, bonding and fixing as conditions allow; handover when the response crew arrives; emergency disposal; acceptance of the temporary measures, signed by both the crew and the property manager; follow-up, which means promptly commissioning a qualified curtain wall contractor for the repair and cooperating in the incident investigation report; and uploading the records to the platform. Note steps three and four: the glass replacement comes later.
3.2 The Hongkou drill: cordon, dedicated watcher, removal of the damaged remains, measured sealing
The 2024 emergency drill in Hongkou District simulated a spontaneous breakage on the fourth floor. Its sequence: report in time, dispatch the response, temporary sheltering – cordon tape, a dedicated watcher, protection around the danger point – on-site coordination, a disposal plan with sealing materials prepared, execution – certified work at height removes the damaged remains, the opening is measured, sealed and braced – acceptance, clearing of debris, and sign-off by the owner. The drill is more concrete than the document: the remains must be removed by rope access, and the sealing must be measured and braced.
3.3 The order both documents agree on: people first, glass second
Read side by side, the two procedures agree on the sequence: protect and cordon first, separate people from the danger, then touch the glass. This is not the script of any one company; it is the order fixed in government documents. The first object of temporary protection is the pedestrian and the occupant; the broken pane comes second.
4. Three lines of defence, each with its own object
4.1 The cordon: how wide
Industry articles commonly quote a safe radius of one tenth to one fifth of the facade height. This is an empirical value, not a mandatory code provision, and it must be adjusted for foot traffic, wind direction and strength, and any entrances below. On street-front buildings the line should reach the kerb, not merely the edge of the pavement. For the safety nets themselves, GB 5725-2025, Fall Protection – Safety Nets, took effect on 1 September 2026 replacing the 2009 edition, with the top protection class of horizontal nets tested against a 100 kg steel ball in free fall from 7.0 m – buy against the new edition.
4.2 The seal: measure, block, brace
The Hongkou drill is specific: measure the opening, seal it and brace the fixing. Sealing materials keep out fragments and wind; they carry no load. The much-quoted tape-in-a-star pattern helps only with minor cracks – tape cannot hold tempered granules together and cannot stop a whole panel from dropping, so place no hope in it.
4.3 The removal: broken remains come down by certified rope access
The remains seated in the frame must eventually be removed by certified work-at-height personnel, watching the wind, the rain and the street below. This is not a job for a mop handle, and no cleaner or guard should climb out of a window for it. The words within reach in the Qingpu procedure mark the boundary for the manager: sealing, blocking, bonding and fixing where they can be reached, and waiting for the crew everywhere else.
5. Why the cordon counts for more in court than the purchase order
5.1 Article 1253 of the Civil Code: fault is presumed, the burden of proof sits with the manager
Article 1253 of the Civil Code provides that where a building or structure, or anything placed or suspended on it, falls or detaches and causes harm, the owner, manager or user bears liability unless it can prove absence of fault. Note the direction: the injured party does not have to prove fault – the manager has to prove innocence.
5.2 The words of the judgement: warning signs or barriers must be set up in time
In a case from Anyuan District Court in Pingxiang, Jiangxi, published by China Court Net, a car was crushed by falling facade material. The reasoning reads: liability for damage from falling building parts follows presumed fault, and the manager has the duty to inspect, maintain and repair the building, and upon discovering a possible safety hazard, to set up warning signs or barriers in time to prevent the accident; the property manager failed to prove due care and was ordered to pay full compensation. In plain words: the speed of the replacement is not yours to control, but the cordon is something you can set up the same day – and the court looks at exactly that.
5.3 One broken pane legally triggers a safety appraisal of the whole facade
Article 15 of the Measures for the Safety Maintenance of Existing Curtain Walls lists the situations that require the maintenance responsible party to commission a safety appraisal, and the first item covers abnormal deformation, detachment or bursting of panels or connecting members. One spontaneous breakage is therefore not a matter of swapping one pane; it triggers an appraisal obligation for the whole facade. And whether the temporary measures were taken, and whether they were recorded, can be verified from outside: in the closed loop of the Shanghai urban grid management platform, rectification orders and reminder orders are issued fortnightly with photographic evidence – there is nowhere to hide.
6. What about the people inside the room during this week
6.1 With the inner lite broken, what a fabric layer on the room side stops and what it does not
For the days when the inner lite has failed, the frame still stands and the room is still in use, a fabric layer hung on the room side catches falling granules, dust and a share of the glare, and the office keeps working. The boundaries must be stated plainly: the fabric carries no load, it cannot replace sealing, and it cannot stop an outer pane from falling; it changes neither the stresses nor the residual strength of the glass, and it extends no service life; it replaces neither the cordon, nor the appraisal, nor the repair by a qualified contractor. It does one thing: it keeps the fragments on the room side while life goes on. One caution – anything hung on the room side changes the airflow over the glass, so in winter watch for condensation caused by blocked airflow; do not trade one problem for another.
6.2 On the repair day, the screen must give way full-width
When the crew arrives they occupy the whole opening, and the shading layer on the room side must retract full-width without dismantling the frame, without touching the glass and without occupying the work area. This is arranged in normal times: a reversible shading retrofit means flexibility day to day and a clear path on the repair day. Some facility teams write the screen into their daily routine precisely so that it is always ready to retract – how one team ran the screen after handover has been recorded before – and on the repair day nobody spends half a morning dismantling shading first.
7. Three timelines not to be confused: emergency, appraisal, repair
7.1 Emergency: the same day
Cordon, seal, record, report – all of it happens the same day. Tape, warning signs, a dedicated watcher, photographs, the platform filing: these five are worthless late and cheap now.
7.2 Appraisal: commission on bursting, and keep the statutory cycles
A bursting event is itself a listed trigger in Article 15, so the appraisal should be commissioned proactively. Keep the routine cycles in mind too: an existing curtain wall should in principle undergo a safety appraisal every ten years from handover; JGJ 102-2003, the Technical Specification for Glass Curtain Walls, requires a comprehensive inspection one year after completion and every five years thereafter. Local rules can be stricter: the housing authority of Xian requires checks of sealing and breakage at least once a year, with dedicated personnel on daily patrol where crowds gather – schools, hospitals, stations, malls – and where facades stand close to roads or over entrances. How to grade and rectify the findings of an annual inspection has been recorded in full elsewhere.
7.3 Repair: a qualified curtain wall contractor, and archives at the end
The repair belongs to a qualified curtain wall contractor, the procedure adds cooperation in the incident investigation report, and the completion documents must be kept – what acceptance measures and what it signs can follow the checklist of a shading retrofit. Filed properly, these papers are your evidence the next time a dispute starts.
8. A one-page list: who does what in these days
| Responsible party | Same-day actions | Records kept | Deadline |
|---|---|---|---|
| Property manager / maintenance responsible party | Report, cordon, warning signs, dedicated watcher | Call log, site photos, watch roster | Immediately on discovery, same day |
| Property manager with the response crew | Handover of the scene, sealing and bracing within reach, debris clearing | Signed acceptance of temporary measures, handover sheet | On the spot when the crew arrives |
| Owner | Commission the safety appraisal, confirm the repair plan and budget | Appraisal contract, reply to the rectification order | As soon as possible after the burst; appraisal has statutory cycles |
| Curtain wall contractor | Rope-access removal, measured sealing, panel replacement | Completion documents, incident investigation report | Per production and weather windows, archived after repair |
Back to the question in the title: why not simply wait for the replacement crew. Because the days of waiting are not a gap but the window of highest risk; because the law does not look at your purchase order, it looks at your cordon; and because in the design of the rules one bursting pane already reaches toward the health of the whole facade. Temporary protection is not procrastination – it is the work of closing uncontrollable days inside a controllable envelope of cordons, watchers, records and a commissioned appraisal.
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