Refurbishment is the period when a building is most exposed to fire. Protection systems are partly out of service, the fire load is unusually high, ignition sources are numerous, and many people who do not know the building are inside it.
Four risks rise at once
- Protection falls. Sprinkler lines are cut, detectors covered, compartments penetrated, escape routes closed.
- Fire load rises. Packaging, timber formwork, insulation materials, paint and solvent, waste piles.
- Ignition sources rise. Welding, cutting, grinding, portable heaters, temporary electrical installations.
- The human factor changes. Subcontractors do not know the building, the alarm system or the escape routes.
A hole in a fire compartment is the quietest risk. An opening cut for a cable or pipe stays open until the job finishes. In a fire, smoke reaches the adjacent compartment in minutes, not hours. Even temporary penetrations must be closed with temporary fire-stopping.
Managing hot work
Welding, cutting and grinding are among the known leading triggers of industrial fires. The permit system covers:
- Clearing the work area of combustibles or protecting them with fire blankets.
- Preventing sparks reaching floors below and adjacent spaces (holes, voids, ducts).
- Having a suitable extinguisher at the work position.
- Posting a watch during the work.
- Keeping a watch after the work finishes. This is the most frequently skipped step and the one that makes the most difference; hot fragments can cause ignition hours later.
- Closing the permit and recording it.
Where possible, avoiding hot work altogether is best: mechanical cutting instead of flame cutting, fasteners instead of welding, prefabrication off site.
The impairment plan
| Step | Content |
|---|---|
| Scope and duration | Which system, which zone, for how long |
| Authorisation | A defined person at site; a subcontractor cannot close valves alone |
| Notification | Site management, security, alarm receiving centre, insurer |
| Compensating measures | Fire watch, temporary detection, extra extinguishers, hot work restrictions |
| Tagging | A visible tag on the closed valve |
| Sectioning | Keeping the impaired zone as small as possible |
| Restoration | Verification by flow test; checking the valve position alone is not enough |
The critical principle: the impaired area must be the smallest zone possible. Shutting the whole building is easy; the right answer is to isolate only the work area using the zone valve.
Temporary measures
- Temporary detection. Independent, wireless smoke detectors or linear heat cable.
- Temporary suppression. Enough portable extinguishers of the right type in the work area.
- Temporary escape routes and signage. An alternative to any closed exit, identified and signed.
- Temporary fire-stopping. For compartment penetrations left open.
- Waste management. Combustible waste removed daily; accumulated site waste is the most easily ignited fire load there is.
- Temporary electrics. Trailing cables, distribution boards and heaters inspected.
Subcontractor induction
Every team entering should get a short briefing: what the alarm sounds like and what to do, where the escape routes are, where the assembly point is, who issues hot work permits, and which valves are not to be touched. That ten-minute induction is the highest-return measure of the whole refurbishment period.
Restoration check before handover
- Have all closed valves been reopened and verified by flow?
- Have disabled detection zones been restored at the panel?
- Have compartment penetrations been permanently sealed?
- Have removed sprinklers been refitted and protective caps taken off?
- Do sprinklers relocated by the works comply with the obstruction rules?
- Have escape signage and emergency lighting been reinstated?
- Do fire doors close freely?
- Has the as-built been updated and every impairment record closed out?
Frequently Asked Questions
How large should the impaired area be during refurbishment?
The smallest zone possible. Shutting the whole building is easy, but the right answer is to isolate only the work area using the zone valve.
What is most often skipped in hot work?
The watch kept after the work finishes. Hot fragments can cause ignition hours later.
Must temporary compartment penetrations be sealed?
Yes. An opening cut for a cable or pipe must not stay open until the job ends; even temporary penetrations need temporary fire-stopping.
What does a subcontractor induction cover?
The alarm sound and what to do, escape routes, the assembly point, who issues hot work permits, and which valves must not be touched.
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Download MEP Calc on the App StoreNFPA 13 (2025) · NFPA 20 (2025) · NFPA 25 · NFPA 241 · BS EN 12845:2015+A1:2019 · FM Global DS 10-3, DS 2-0. The findings here are typical defect patterns defined in the standards and survey guidance, not an account of events at any particular site.