30 minute fire doors are doors that can retain fire for up to 30 minutes to give occupants the necessary time to evacuate safely, they are constructed as set out below but must be fitted with the correct frame and fittings to acheive the 30 minute rating.
Construction of a fire door
FD30 (30 minutes) fire doors are usually 45mm thick, this is different to the standard door thickness of 35 mm, FD60 (60 minute) fire doors are most commonly used in industrial or commercial settings and are usually 54mm thick.
Bespoke construction of fire doors can can make such doors have a rating of 4 hours or more.
Most 30 minute fire doors have a solid core construction which can include: particleboard, chipboard, flaxboard and solid timber, the assembly of a fire door can however vary greatly with some having:
- A timber framing around the core with a laminated veneer;
- A lipping (5-20mm thick) around the core with a veneer on top;
- In some cases a plywood, veneer or MDF facing is glued on to the core without framing or lippings.
There is absolutely no preferred construction method, as long as the desired fire rating is achieved.
All fire doors must be fitted with the approved intumescent strips which play a significant part in achieving the fire door rating.
When subjected to heat, the intumescent strips expand and seal the gap between the door edge and the frame, the intumescent seals can be fitted within the door frame or grooved into the door edge.
Advice on the intumescent strips can be obtained from the test evidence report, which we can provide.
The material from which the door frame is constructed (e.g. softwood, hardwood or MDF), as well as its section sizes must comply with the required standards. Furthermore, essential hardware (ironmongery) must also have its own individual test evidence to show fitness for purpose.
See lots of 30 minute fire doors