Fire Stopping in Slough: Cable-Heavy Buildings and Fit-Out Handover

Why Slough buildings are prone to this

Lots of power, lots of data, and lots of change.

Slough Trading Estate holds more than 30 data centres, along with offices and units that are fitted out, let, and fitted out again. Offices across the borough follow the same pattern. A floor is cabled, a tenant leaves, the next one reroutes.

Every time a cable tray crosses a fire wall or floor, that opening needs a tested seal. Every time cables are added, the seal is cut or pushed aside. The room still looks tidy, and the compartment is open.

What fails on cable-heavy sites

Four faults account for most of what we expect to find.

• Cables added to an old seal. The seal was sized for the cables there on day one. More cables, no more sealing.
• Wrong product. A tube of sealant in a gap that needs a tested system for that tray, wall and fire rating.
• Abandoned openings. Old routes left open after a cable was stripped out.
• Risers closed at the top but not at each floor. Smoke and fire then travel up a cupboard that looks neat from the corridor.

Where cabling changes often, ask your contractor for a seal that can be reopened and re-closed when cables are added. Several tested systems do this. We advise on what suits your tray layout during the survey.

The principle is the one behind passive fire protection. The structure only holds a fire back if every opening in it is sealed.

Evidence a principal contractor needs at handover

A sealed building and a documented one are not the same thing.

A principal contractor, landlord or managing agent will usually ask for a record that shows each penetration, what seals it, and who fitted it. We keep it simple.

1. 1Numbered schedule. Each location has a number and a plan reference.
2. 2Before and after photos. One of the gap, one of the finished seal, tied to the same number.
3. 3Product and method. What was used, and the fire rating of the wall or floor it sits in.
4. 4Certificate. Work done by our BM TRADA Q-Mark / FIRAS-certificated contractors comes with third-party certification for your fire safety file.

If a handover is running late, ask for the survey first. It gives you the count before you commit to a repair date.

Our survey figures, and how to read them

Two surveys. A guide, not a benchmark.

A 5-storey hotel: 327 locations checked, 305 needing fire stopping (93%). A restaurant: 80 checked, 66 needing it (83%). Together 407 checked and 371 (91%) needed work.

We have no data building figure and we will not guess one. Read the full survey findings. A survey is the only way to find your own number. Start with a fire stopping survey, or for higher-risk buildings an intrusive compartmentation survey.

What it costs

We price from the count, not a guess.

A survey is a day or two of an engineer's time scaled by floor area and risers. The repair price depends on how many locations need sealing and what they pass through. We give a fixed price once the list exists. Our fire stopping service page has the detail, and the guide to choosing a fire stopping contractor helps you compare quotes. A fire risk assessment is a separate service that sits alongside.

Sources

• Approved Document B: Fire safety (GOV.UK)
• Regulatory Reform (Fire Safety) Order 2005 (legislation.gov.uk)
• Building Safety Act 2022 (legislation.gov.uk)

Updated October 2026 by Sebastian Grabowski, DC Fire & Security, 2 Winsdon Court, Luton LU1 5LZ.