Door Terms Glossary

The world of doors is full of jargon so we have put together a handy glossary of terms. If you need help on anything technical then ask the experts:

Aperture: An opening created by a cut-out through a door leaf that is to receive glazing or other infilling.

Assessment: Application of expert knowledge to data established by a series of fire tests of a door leaf construction or particular design type to extend the scope of the results.

BM Trada: BM Trada provides third-party certification fire services for manufacturing, installation and maintenance service for fire doors.

Butt Joint: A technique in which two pieces of material are joined by simply placing their ends together without any special shaping.

Certifire: Certifire is an independent third-party certification scheme that assures performance, quality, reliability and traceability of products and systems.

dBRw: Rw is the weighted sound reduction index in dB (decibels) and it describes the airborne sound insulating power of a building element.

Door Leaf: Hinged, pivoted or sliding part of a door assembly or door set.

Doorset: Complete unit consisting of a door frame and a leaf or leaves, supplied with all essential parts from a single source.

Double Action Door: Hinged or pivoted door that can be opened in either direction.

Fanlight: The space between a frame transom rail and the frame head that is generally glazed.

Fire Resistance: Ability of a component or construction of a building to meet for a stated period of time some or all of the appropriate criteria specified in BS476 Pt.22 or BS EN 1634.

Free Area: Also referred to as free air flow. The amount of free space for air to move through the covers. It can be expressed as a square or cubic measurement or percentage of the total cover size.

Gasket: A rubber seal used to fill the gap between two surfaces preventing various forms of leakage.

Hardware: Door set / door assembly components usually in metal that are fitted to a door or frame to provide for the operation and securing of a door leaf.

Head: The top edge of a door leaf.

IFC Certificate: IFC Certification Ltd is a UKAS accredited and internationally recognised provider of high quality customer focused independent third party certification.

Intercalated Graphite: One of the three main types of intumescent materials which produces an exfoliated, fluffy material during expansion. The activation temperature is typically around 200 ºC.

Intumescent Seal: Seal used to impede the flow of heat, flame or gases, which only becomes active when subjected to elevated temperature. Intumescent seals are components which expand, helping to fill gaps and voids, when subjected to heat in excess of ambient temperatures.

Jamb: The vertical side member of a door or window frame.

Kerf: A slot cut along the wooden door frame, generally the width of a standard saw blade.

Meeting Stile: The gap where two swinging doors meet.

Mitre: Two pieces forming an angle, or a joint formed between two pieces of wood by cutting bevels of equal angles at the ends of each piece.

Mortice: A recess or hole formed in one piece to receive a projection or tenon on the end of another piece.

Neoprene: A synthetic polymer resembling rubber, resistant to oil, heat, and weathering.

Operating Gap: The space between the edges of a door leaf and the door frame, floor, threshold or opposing leaf, or over panel that is necessary to enable the door leaf to be opened and closed without binding.

Pa: A unit of pressure. The pressure exerted on an area of 1 square metre by a force of 1 newton.

PETG (Polyethylene Terephthalate Glycol): A thermoplastic polymer created through the copolymerisation of PET and ethylene glycol.

PU Foam (Polyurethane Foam): A plastic material used especially to make paint or substances which prevent water or heat from passing through.

PVC (Polyvinyl Chloride): A thermoplastic material used for many purposes, available in rigid and flexible form.

Rebate: An edge that has been cut to form a step, usually as part of a joint.

Side Screen: A lateral extension of a door glazed to provide light or vision that may be a separate component using separate jambs or form part of a door frame using mullions.

Single Action Door: Hinged or pivoted door that can be opened in one direction only.

Sodium Silicate: One of the three main types of intumescent materials which gives a uniaxial expansion and hard foam which exerts considerable pressure activating at around 110 – 120 ºC.

Test Evidence / Primary Test Evidence: Evidence of the performance of a fire door that is derived from a full scale fire test on that particular product design by
the test sponsor.

TPE (Thermoplastic Elastomer): A polymer blend or compound which, above its melt temperature, exhibits a thermoplastic character that enables it to be shaped into a fabricated article and which, within it’s design temperature range, possesses elastomeric behaviour without cross-linking during fabrication. This process is reversible and the products can be reprocessed and remoulded.

Vision Panel: A panel of transparent or translucent material fitted into a door leaf to provide a degree of visibility from one side of a door leaf to the other.