When is an FD30 fire door required in a UK dwelling?

In dwellings of 2 or more storeys, fire doors are required between habitable rooms and the protected hallway/landing. Two-storey houses need FD20 minimum, while 3+ storey dwellings and all loft conversions require FD30 doors. Integral garages always need FD30S doors (with smoke seals). In HMOs, all habitable room doors to common areas must be FD30S (with smoke seal). These requirements come from Approved Document B, Volume 1.

What is the difference between FD30 and FD30S fire doors?

FD30 provides 30 minutes of fire resistance (integrity). FD30S adds an "S" for smoke seal, meaning the door includes cold smoke seals that prevent smoke passage at ambient temperatures. Flat entrance doors, HMO room doors, and doors to protected stairways all require the "S" designation with combined intumescent and smoke seals. The smoke seal is typically a nylon brush or blade type fitted within the intumescent strip.

What ironmongery is needed on a fire door?

All fire door ironmongery must be CE-marked and fire-tested as part of a door assembly. Requirements include: 3 x fire-rated hinges (BS EN 1935, grade 13), a self-closing device (BS EN 1154), intumescent strips in the frame or door edge, a fire-rated lock or latch (BS EN 12209), and signage. Letterplates are generally not permitted unless fire-rated to BS EN 13724. All items must be fitted per the door manufacturer's installation instructions.

Do fire doors need intumescent strips?

Yes, all fire doors require intumescent strips to seal the gap between door and frame during a fire. The intumescent material expands when heated to approximately 200 degrees C, sealing gaps and preventing fire and smoke passage. Standard sizes are 10mm x 4mm for FD30 doors and 15mm x 4mm for FD60 doors. They are fitted into a groove in either the door edge or the frame rebate. Some locations also require a combined intumescent and cold smoke seal.

Can I have a glazed panel in a fire door?

Yes, but the glazing must be fire-rated to match the door rating. For FD30 doors, Georgian wired glass (6mm) or proprietary fire-rated glass such as Pyran S or Pyroguard can be used. The maximum glazed area is typically 0.5 square metres unless the manufacturer has test evidence for larger panes. The glazing beads must incorporate intumescent backing strips. All glazed fire doors must be tested as complete assemblies to BS 476-22 or BS EN 1634-1.

Fire Door Specification Calculator

Fire Door Specification Calculator — FD30/FD60 Rating per Part B

Determine fire door ratings, ironmongery and intumescent requirements based on UK Building Regulations Approved Document B.

Building Type

Select the building purpose group per AD B

Number of Storeys

Total storeys including basements

Door Location

Where the fire door will be installed

Number of Doors

Total fire doors to specify

Door is on an escape route

Escape route doors need additional signage

Door includes glazed panel

Fire-rated glazing will be specified if enabled

How We Calculate This

This calculator determines the correct fire door specification based on Approved Document B of the UK Building Regulations, BS 476-22, and BS EN 1634-1. It considers the building type, number of storeys, door location and intended use to recommend the appropriate fire rating, ironmongery and sealing requirements.

How it works

Building type: Dwellings, flats, HMOs, commercial and care homes each have different fire door requirements under AD B.
Door location: The position of the door within the building determines the required fire rating. Flat entrance doors, stairway enclosures and compartment walls have the highest requirements.
Storey count: Buildings of 4+ storeys may require upgraded ratings (FD60) for certain locations.
Ironmongery: All components must be CE-marked and tested as part of the fire door assembly to BS EN 1634-1.