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Building components · Openings & Frames

Door Leaf

Explains the leaf as the moving half of a doorway, distinct from the fixed surround that carries it and from the products it is faced or cored with.

Form:Board or sheetRoles:SeparationProtectionWeather control

Educational reference entry. What this element has to do, and whether any particular arrangement of it is adequate, depends on the whole assembly, the loading, the exposure, local requirements, the manufacturer's instructions and qualified professional design.

Overview

What a leaf is

The leaf is the part of a door that moves. It is hung from the frame, occupies the opening when closed and vacates it when open, and it carries the hardware by which it is held shut, latched or locked. Everything a doorway is asked to do when it is closed is done by the leaf, and everything it is asked to do when it is open is a matter of the leaf being out of the way.

Its construction is what decides what it can do closed. A leaf is a made-up element — a core, facings, edges and whatever is built into it — and the difference between one that merely divides two spaces and one that is part of a fire or acoustic separation lies inside it rather than on its surface. That is also why a leaf is only ever one part of such a separation: the frame it hangs in, the seals around it and the hardware on it are the rest, and the leaf carries nothing on its own.

Boundaries

How it differs from nearby elements

The distinctions that keep this entry from being a restatement of its neighbours.

  • It is not a door frame. The frame is the fixed surround built into the opening, and it is what carries the leaf's weight through the hinges and takes the forces of it being used; the leaf is the moving element, and it can be rehung or replaced without the frame changing at all.
  • It is not a door threshold. The threshold is the fixed base condition beneath and around the opening, resolving water, wear and level access; the leaf is what passes over it, and the clearance left between the two is deliberate rather than a defect.
  • It is not a door panel product. Facings, cores and moulded panel products are published material entries covering what a leaf is made up from; the leaf is the position — the moving element in the opening — and the same position is realised in timber, in board, in glass and in steel.

Terminology

Common names and aliases

These names describe the same element. The library keeps one entry per component so that a trade term or a regional name never becomes a second, thinner page.

  • door slab
  • door blank
  • shutting leaf

Dependencies

What it depends on

What has to be right elsewhere for this element to do its job.

  • How it is hung, since its whole weight and every force applied to it reaches the frame through the hinge side.
  • The clearance left around its edges, which has to let it swing and let it move with humidity without opening a gap where one is not wanted.
  • What it is made up from internally, because that rather than its appearance governs what it does when closed.
  • The seals and hardware fitted to it, since sound, smoke and draughts pass around a leaf rather than through it.

Considerations

Topics that genuinely apply here

Subjects worth discussing about this element. These are discussion topics, never measured values, ratings or performance claims.

Fire

Where a doorway is required to resist fire, the leaf is one component of an assembly that includes the frame, the seals and the hardware, and changing what is fitted to a leaf can change what the assembly does.

Acoustic

The gaps around a leaf commonly matter more to sound transfer than the leaf itself, which is why a heavy leaf in a loosely sealed frame can perform worse than expected.

Movement

Timber-based leaves take up and give off moisture and change shape with the seasons, so a leaf that binds in one part of the year and swings freely in another is behaving normally rather than failing.

Durability

A leaf is a mass that is accelerated and stopped many times a day, and wear shows first at the hinge side, the latch edge and the bottom rail where it meets traffic and cleaning.

Materials

Commonly formed from

Material families this element is commonly realised in. This states common practice only — it is not a statement that any of these materials suits this component in a particular building, which depends on the whole assembly and on qualified review.

Materials LibraryHardwood timber →Hardwood is met in solid leaves, in edge lippings and where an external leaf has to take weather and wear.Materials LibraryMedium density fibreboard →Moulded and flat MDF facings are among the most widely encountered internal leaf surfaces.Materials LibraryHoneycomb Panel →A light cellular core between facings is the common hollow-core internal construction.Materials LibraryChipboard →A solid particleboard core is the common alternative where a heavier and more solid leaf is wanted.Materials LibraryGalvanised steel →Steel leaves are encountered where security, durability or high-temperature behaviour governs the choice.

Assemblies

Building systems this element is met in

The role this component fills inside each assembly. A role describes what the element does there — it is not a statement that this component suits that system in any particular building.

ProtectionControl layerDoor Threshold Interface →Completes the envelope closure at the opening when shut, and leaves the threshold directly exposed when open — which is why the threshold is designed for both conditions.ProtectionEdge and terminationFramed Partition →Occupies the opening formed in the partition framing, and its weight is a demand the framing around the opening has to be arranged for.ProtectionSeparating Wall →A doorway is the weakest point in a separating wall, and the leaf together with its perimeter seals is what closes it.ProtectionEdge and terminationGlazed Partition →Glazed leaves within glazed partitions are the moving element in an otherwise fixed screen, and their hardware and edge conditions differ accordingly.

Clarifications

Commonly misunderstood

  • That a door that sticks has swollen. The frame may have moved, the hinges may have dropped, or the opening itself may have settled — the leaf is simply where the symptom shows.
  • That a heavier leaf is a better one. Mass is only one of the things a leaf does, and a heavier leaf loads its hinges and its frame more, which is a demand on the fixed side of the opening rather than a free improvement.

Conversations

Questions for qualified professionals

Questions worth asking someone with the project in front of them. This page cannot answer them.

  • What is this leaf made up from internally, and what is that construction intended to do?
  • Is the doorway required to resist fire or provide acoustic separation, and which parts of the assembly is the leaf one of?
  • How is the leaf hung, and can the frame and the surrounding construction carry its weight at the hinge side?
  • What clearances and seals are intended around the leaf, and how are they maintained as it moves with the seasons?

Go deeper

Related Build Design Hub guides

Planning guidance behind the decisions this element involves.

Preparation

Related planning checklists

Owner-side preparation before the conversation where this element comes up.

What this entry does not do

  • This entry describes a position. It states no dimension, weight, clearance, fire rating, acoustic value or hardware schedule, and none can be inferred from it.
  • Fire-resisting and acoustic doorways are assessed as complete assemblies rather than as leaves, and substituting or altering any part of such an assembly is a regulatory matter for qualified advice.

Openings & Frame Elements

The frames, heads, jambs, sills, thresholds and closers that form and finish an opening through a wall.

Browse all openings & frames entries →