Technical Guide
Some openings in fire doors are accidents. Others were made on purpose — for ventilation, for door-entry and access control wiring, or to get pipes and cables past a door opening. Deliberate openings are harder to deal with because somebody needs them to stay. This guide explains how those items are resolved without undermining the doorset.
In the leaf
Grilles fitted to let air move between spaces, often in plant rooms, kitchens, stores or older flat conversions. Acceptable only with a product and position supported for that doorset and a fire strategy that allows it.
Through the leaf or frame
Cables for electric locks, door-entry, access control or door status contacts. Supported products route power across the hinge side; improvised holes through the leaf or frame are not the same thing.
Around the frame
Pipes, trunking and cables run through the wall beside or above the frame, or through the frame-to-wall gap itself. The door may be fine; the construction around it is not.
An intumescent grille is designed to swell and close under heat. Until it does, it is an opening. That means smoke at lower temperatures — the smoke most likely to affect escape early in a fire — can pass through it unless the design includes something to stop that.
For that reason, whether a grille can stay in a given door is not a joinery question alone. It depends on what the door is required to do in the building's fire strategy, whether a supported grille of that size and position exists for the doorset, and whether ventilation can be provided another way.
Cabling to door hardware is usually a design fault rather than a door fault: the installer needed power at the leaf and drilled the nearest route. The long-term fix is to reroute through a product designed for that purpose, then make good the original hole where the doorset allows, or quote replacement if it does not.
Where services pass through the wall around the door, the door itself may need nothing. The item belongs to fire-stopping of the surrounding construction, and the frame-to-wall junction is part of the doorset installation. We deal with the frame junction; wider fire-stopping may need a specialist contractor, which we will say plainly.
Hypothetical example
Illustrative only: a door-entry upgrade has left a cable passing through the leaf near the lock. The cable is rerouted by the relevant contractor, the hole assessed, and either made good with a supported method or the leaf priced for replacement if the damage is too close to the lock and seals.
Hypothetical example
Illustrative only: a timber louvre has been cut into a plant room fire door for ventilation. There is no evidence for it and it is not intumescent. The options put to the client are an alternative ventilation route with the leaf replaced, or a supported doorset with a tested grille if the fire strategy allows one.
GOV.UK, Fire Safety (England) Regulations 2022: fire door guidance (updated 8 August 2025; accessed 26 September 2026) — damage, alterations, seals and signs that a door may need further attention.
GOV.UK, Approved Document B, Volume 2 (2019 edition incorporating 2020, 2022 and 2025 amendments; collated copy also showing later 2026 and 2029 changes, which apply only from their own commencement dates) (accessed 26 September 2026) — guidance on fire-resisting construction, fire doors and the protection of openings and penetrations.
Product suitability for any grille or hardware power transfer device is taken from the doorset and product manufacturer's evidence for that application.
Related guides on alterations, frames and the repair decision.
Send us the report wording and photographs of each opening. We will tell you which can be kept with a supported product, which need removing, and price the works door by door.