The door that connects the integral garage to the house must be a fire door, and it’s not a matter of opinion, or because a supplier suggested it. It’s a matter of law. Building regulations state that doors to integral garages must be fire doors, and more specifically, they must have at least an fd30 rating, meaning they provide 30 minutes of fire resistance. This is the case in the new build phase and also in the case when building work is done that requires a compliance check for the area being worked in, which is most often the case when a garage is converted. If you are simply doing an internal door replacement or like a door swap in an existing building, then the position is less clear and is worth confirming with the building authority in your jurisdiction.
What does ‘FD30’ stand for?
When talking about FD30 doors, the 30 minutes refers to the integrity of the door. That is, how long the door will hold the barrier against flames and hot gases. It does not mean the door will ‘fail’ after exactly 30 minutes. In practice, fire doors that are ‘well specified’ and installed correctly, tend to perform better than the time period they are rated for. What FD30’s specify is that the door has been subjected to the relevant fire tests for that specific timeframe under either BS 476 or EN 1634.
An FD30 assembly is not just the door leaf, but also the frame, the ironmongery, the seals, and the hinges, which all constitute the tested system. Fire doors are required to have ‘intumescent’ seals, which means that they expand due to heat in order to fill the gap between the door and the frame. Fire doors are also required to have ‘cold smoke’ seals. Regardless of what the door is made of, a standard softwood frame, standard hinges, and a solid-core door do not make a fire door.
Requirements for floor levels
Regarding the integral garage floor level, the Approved Document B also states that the garage floor should be 100mm lower than the floor of the adjacent living area, or there should be a step, to mitigate the potential of fuel — petrol, oil — migrating into the house in the case of a spill. This is a separate issue from the door requirement, but still a part of the same section. Therefore, when a door between the garage and house is to be specified or replaced, it would be good to check whether this floor level requirement is complied with.
Things to consider when specifying the door
Look for a third-party certificate, not a self-declaration by the manufacturer. In the UK, the main certifying bodies for fire doors are Certifire and BM Trada Q-mark. The certificate should contain a number corresponding to a particular tested configuration — that is, the exact door leaf, frame, seal, and hardware. If the door that was installed in your property differs from the tested configuration, the certification becomes void.
Not all buyers understand the importance of ironmongery. Some door closers, handles, and hinges are tested as part of their fire door assembly. Replacing a tested part with a look-alike substitute can void the certification. If you are selecting hardware separately, check with the door manufacturer or installer that the combination will still be in the certified configuration.
The self-closing mechanism is a must and is non-negotiable. Approved Document B states that fire doors must be self-closing. If left open, the doors do not provide any protection. If the door between your garage and house does not close by itself, then it is non-compliant, regardless of the specification of the door leaf.