Technical terms, clearly explained
Façade, glazing & fire-door terminology.
Terms you may see in an investigation report, maintenance scope or building manual. These short explanations help you discuss the issue with the team; the building’s specification determines the detail.
- Water ingress
- Unwanted water entering a building. The entry point and the place where a leak becomes visible can be different.
- Curtain walling
- An external wall system supported by the building structure, commonly combining framing with glazing or infill panels. Joints, seals and drainage are important to its weather performance.
- Glazing gasket
- A shaped seal between glass and its surrounding framing or between other components. Its profile and condition matter when assessing the system.
- Glazing bead
- A retaining component used in many framed glazing systems to hold the glass in position. The arrangement depends on the system.
- Perimeter joint
- The junction around a window, door or façade element where it meets adjacent construction. It may include sealants and other weathering or waterproofing components.
- Movement joint
- A joint designed to accommodate movement between parts of the building. Its materials and detailing need to suit the intended movement.
- Drainage slots and weep holes
- Openings intended to let collected water drain out of a frame or construction cavity. They should be considered as part of the system, rather than sealed indiscriminately.
- Cavity tray and DPC
- A cavity tray directs water within a cavity towards an outlet. A damp-proof course (DPC) limits moisture movement through part of the construction. Their locations and continuity can matter during leak investigation.
- Copings, flashings and membrane laps
- Copings protect the tops of walls or parapets. Flashings help shed water at junctions. Membrane laps are overlapping waterproofing or weathering layers whose continuity is part of the detail.
- Insulating glass unit (IGU)
- A sealed assembly with two or more panes separated by a space; double glazing is a familiar example. Moisture between the panes is different from surface condensation.
- Doorset and ironmongery
- A doorset combines the door leaf, frame and specified components. Ironmongery includes items such as hinges, locks and closers. Fire-door performance depends on the appropriate assembly, not the leaf alone.
- Intumescent and smoke seals
- Intumescent seals are designed to react to heat; smoke seals restrict smoke passage. The required type and location depend on the doorset specification.
- BMU, MEWP and RAMS
- A BMU is a building maintenance unit; a MEWP is a mobile elevating work platform. RAMS means risk assessments and method statements, documenting the planned work sequence and controls.