Types of moulding and their profiles

At a glance

Drawn in the chart below. “Where you meet it” is a tendency, not a rule: any profile can be cut for any member.

The profile chart

Each profile is drawn as a section sawn across the moulding, with the wall on the left, the visible face on the right and the top uppermost. The grid squares are 5 mm. The name fixes the shape but not the size: a torus can be 20 mm or 100 mm high, and every size drawn here is only an example.

Many profiles can be used either way up. A cyma reversa is a cap on a dado rail and can equally crown a cornice; the chart shows one orientation, and turning the drawing over gives the other.

Which names we use, and where sources differ

No standard we could read fixes these names. BS 1186-3, the British Standard for wood trim, was not read. The chart follows the meanings used in the heritage thesaurus published through county Historic Environment Records and, where that is silent, Wikipedia and older carpentry texts. They agree on the shapes but not always on the words:

• Cyma recta and cyma reversa. The cyma recta is the S-curve that is hollow above and bulging below; the cyma reversa is bulging above and hollow below. Joinery catalogues commonly say “ogee” for the cyma reversa, but strictly the word can mean either S-curve, so name the cyma or draw it.
• Astragal. The heritage thesaurus calls it a small, convex, circular moulding, which is how the chart treats the bead and astragal as one shape of different size. Wikipedia describes the astragal as the half-round strip that covers the gap between a pair of doors, so the chart draws that sense too.
• Torus. A bolder half-round than a bead or astragal. No source we read gives the size at which one becomes the other.
• Quarter round. Used both for the ovolo and for a plain quarter-circle strip. The chart draws them separately as the ovolo and the quadrant.
• Bullnose and pencil round. Trade terms for a rounded edge, with no fixed radius. The chart shows a bullnose with a radius of half the board's thickness; a pencil round is the same idea with a smaller radius.
• Cove and coving. A cavetto used where a wall meets a ceiling is a cove; coving is the British name for it.

Where each moulding sits in a room

Five mouldings draw the lines of a traditional room, and between them they use the profiles above. The wall between the dado rail and the skirting is the dado, a name taken from the middle section of a classical pedestal; where the pedestal is carried along a wall, its cornice becomes the dado rail.

• 1. Cornice or coving: the moulding at the top of the wall where it meets the ceiling. In classical architecture the cornice is the top of the entablature; in a room it is any horizontal decorative moulding at the head of the wall, and coving is the concave version.
• 2. Picture rail: a moulding fixed high on the wall from which framed pictures are hung.
• 3. Architrave: the moulding that surrounds a door or window opening and hides the joint between the wall and the timber lining that forms the opening.
• 4. Dado rail: a horizontal moulding part way up the wall. It can protect the wall from chair backs but is mainly decorative.
• 5. Skirting: the board along the foot of the wall that covers the junction of wall and floor and protects the wall.

This sheet does not give heights. How high each one sits is a matter of proportion and convention rather than regulation, and published rules of thumb disagree.

Mouldings and fire classification in England

In England, Approved Document B sets reaction-to-fire classes for the surface linings of walls and ceilings. It also says what does not count as a wall or ceiling lining. For walls the list includes architraves, cover moulds, picture rails, skirtings and similar narrow members; for ceilings it includes architraves, cover moulds, picture rails, exposed beams and similar narrow members. That is paragraphs 4.3 and 4.6 of Volume 1 (dwellings) and paragraphs 6.3 and 6.6 of Volume 2 (buildings other than dwellings), in the 2019 edition incorporating the 2020, 2022, 2025 and 2026 amendments, as published on GOV.UK in November 2026.

That is not a general exemption. The wall behind a moulding is still a lining and has to meet the table for its room (Table 4.1 in Volume 1, Table 6.1 in Volume 2). A cornice or coving is not named in the lists, and neither is wall panelling, so whether a particular one counts as a narrow member is a question for the fire engineer or building control. Scotland, Wales and Northern Ireland have their own guidance, which this sheet does not cover. None of this replaces the project's fire strategy.

Specifying a profile so the right one is made

• Draw it. Give the section at 1:1 with the projection, the height and every radius dimensioned. A name alone is not enough: as the sources above show, the same name can cover slightly different shapes.
• Mark the orientation. Show the wall side and which way is up, because many profiles are used either way up.
• Say which size you mean. State whether sizes are nominal (sawn) or finished (planed), and confirm the convention with the workshop that will make the piece.
• Name the material and finish. Paint grade or clear finish, and the species or board, since both affect how crisp a small detail can be.
• Matching an existing moulding. Take a template on site, with a profile gauge or a cut sample, and send it with photographs. Ask the workshop whether it can cut to a template and how long a new cutter takes.

We coordinate the profile drawing and any template with the partner workshop that will make the moulding, before the schedule is fixed.

Ref [M-01]: [skirting] moulding, profile as detail [D-12], drawn at 1:1 on drawing [no.]. Overall section [120 x 25] mm finished, with [torus] head as drawn. Material [MDF, paint grade / oak, clear finish]. Finish [ ]. Where a catalogue or profile name differs from the drawn section, the drawn section governs.

Profile to match the existing [cornice] in [room]. Template to be taken on site by [name] with a profile gauge before production. Where the existing profile is damaged, the reconstructed section is to be agreed on a 1:1 drawing before cutters are ordered.

Standards and sources

• Approved Document B Volumes 1 and 2 (England), 2019 edition with amendments to 2026: Volume 1 paragraphs 4.3, 4.6; Volume 2 paragraphs 6.3, 6.6. Read November 2026.
• Heritage thesaurus (Components) from county Historic Environment Records: the meanings of the profile names.
• Wikipedia: Molding (decorative); Designing Buildings: Moulding
• BS 1186-3, wood trim and its fixing: named only; not read.

Questions we are asked

What is the difference between an ogee and a cyma reversa?

Many suppliers use “ogee” for the cyma reversa, the S-curve that is bulging above and hollow below. Strictly the word can describe either S-curve; the other is the cyma recta, hollow above and bulging below. A drawing is safer than the word.

What is a torus moulding?

A bold convex moulding shaped like a half-circle, found at the foot of columns and used on skirting boards and rails. It is larger than a bead or an astragal, but no source we read gives the size at which one becomes the other.

Is an astragal the same as a bead?

Often by shape: both are small half-rounds, and the heritage thesaurus treats the astragal as a small convex circular moulding. Wikipedia also uses astragal for the half-round strip that covers the gap between a pair of doors, so check which meaning a drawing or a supplier intends.

What is a quirk on a moulding?

A small groove beside a bead, sunk below the surface, that sets the bead apart from the face. A bead with a quirk beside it is a quirk bead.

Do skirting boards and architraves need a fire rating in England?

Approved Document B excludes narrow members such as architraves, cover moulds, picture rails and skirtings from what counts as a wall lining (Volume 1 paragraph 4.3, Volume 2 paragraph 6.3; the 2019 edition with amendments to 2026). The wall behind is still a lining, and cornices and wall panelling are not named in the lists, so the fire strategy and building control decide. Scotland, Wales and Northern Ireland have separate guidance.

How do I specify a moulding so the right profile is made?

Draw the section at 1:1 with the projection, height and radii dimensioned, mark the wall side and the top, state the material and finish, and say that the drawing governs over any catalogue name. Names and sizes differ between suppliers.