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Skirting and architrave installation: profiles, joints, fixings and tolerances

Profiles, mitre vs scribed joints, pre-paint vs post-paint, fixings to studs, movement gaps and defect tolerances for skirting and architrave on residential builds.

By Dan Waring. Last updated 8 May 2026. Verified 8 May 2026.

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TL;DR

Skirting and architrave are second-fix work: they land after paint, not before it. Skirting covers the wall-floor junction and protects the base of the lining; architrave covers the gap between wall lining and door or window jamb. Internal corners on skirting are scribed: cut the second board at a 45-degree mitre, then use a coping saw to follow the front-face profile line, cutting with a slight back angle. The scribed end fits over the face of the first board. External corners are mitred at 45 degrees. Architrave mitres are set off a 5 mm quirk from the jamb edge. Fixings are 40 to 50 mm lost-head nails or brads into studs at 450 to 600 mm centres, with adhesive at the mitre joints. Per the VBA Guide to Standards and Tolerances 2015, gaps at joints exceeding 1 mm within the first 12 months are a defect.

When you do this

Skirting and architrave are second-fix items. The build sequence matters:

  1. Frame is up and passed frame inspection.
  2. First fix trades (sparky, plumber) complete their rough-in.
  3. Plasterboard is hung, set and sanded.
  4. Paint is applied (primer, undercoat and topcoats on walls and ceilings).
  5. Skirting and architrave are fixed. Doors are hung at the same time or just before.
  6. Nail holes and joints are filled and caulked.
  7. Final paint coat on skirting and architrave (or pre-primed boards get their topcoat in place).

Fixing skirting and architrave after paint avoids masking and protects a painted wall surface from the inevitable handling marks. On pre-primed boards, the standard approach is prime off-site, install, fill and caulk in place, then apply the topcoat. This is the common industry practice for new construction in Australia (verified 2026-05-08 via Intrim Mouldings installation guides and Houzz AU discussions).

Who’s involved

TradeRole
ChippyMeasures, cuts, fixes all skirting and architrave. Hangs doors at the same time.
PainterFills nail holes, caulks to wall, applies topcoat after chippy is off.
CabinetmakerCoordinates around cabinetry kickboards and scribes at cabinetry-to-skirting junctions.
PlastererResponsible for the finished plasterboard surface the skirting and architrave sit against.

The chippy and painter must coordinate: if the painter wants to apply the topcoat before the chippy installs, the chippy needs to install on a finished surface without damage. Most production builders reverse this: chippy installs on the primed surface, painter finishes in place.

Profiles

Skirting

Skirting profiles range from simple bevelled or half-round edges (contemporary) to colonial, ogee and bar profiles (traditional). Profile height should be proportioned to ceiling height:

Ceiling heightSkirting height (typical)Architrave width (typical)
2.4 to 2.5 m135 mm90 mm
2.5 to 2.7 m185 mm90 mm
2.7 to 3.0 m230 mm115 mm
Over 3.0 m285 mm115 mm

Source: Intrim Mouldings profile selection guide (verified 2026-05-08). These figures apply to traditional and classic interiors; contemporary homes typically run slimmer proportions at the builder’s or client’s discretion.

Architrave

Architrave hides the gap between the wall lining and the door jamb or window reveal. The same profile family as the skirting is standard; mixing profiles on the same project is a specification decision, not a structural one.

Materials

MaterialWhere it worksWhere it doesn’t
Finger-jointed pine (primed)Interior dry areas, standard new constructionWet areas, direct water contact
Clear pineInterior dry areas, where grain is specifiedWet areas
MDF (standard)Interior dry areas, smooth finish preferenceBathrooms, laundries, areas with repeated moisture
MR MDF (moisture-resistant)Bathrooms, laundries, high-humidity interiorsDirect water or flooding exposure
HardwoodFeature rooms, period restorationsCost-sensitive projects

MR MDF is moisture-resistant, not waterproof. In bathrooms and laundries, seal all cut ends with a primer coat before installation to limit moisture uptake (verified 2026-05-08 via Intrim Mouldings materials guidance and trade discussions on Houzz AU).

Steps: skirting installation

1. Stud location

Use a stud finder to locate studs (typically at 450 mm or 600 mm centres). Mark lightly in pencil at the top of the skirting run. All fixings must hit framing; nails into plasterboard alone will not hold.

2. Internal corners: scribe joint

Internal corners are scribed, not mitred. A scribed joint holds tight when the timber moves seasonally; a mitre at an internal corner will open as humidity changes.

Method:

  1. Run the first board square into the corner. Fix it.
  2. On the second board, cut a 45-degree mitre (as if mitring the corner).
  3. Use the mitre cut as the template: run a coping saw along the profile face, cutting at a slight back angle (1 to 2 degrees undercut). This produces the scribe.
  4. Fit the scribed end over the face of the fixed board. The profile should sit flush with zero gap visible from normal standing height.

Tight scribes require sharp tooling and trial fitting. A slight undercut is the chippy’s friend: it lets the front face pull tight even if the wall is slightly out of square.

3. External corners: 45-degree mitre

External corners are mitred at 45 degrees. Apply PVA adhesive to both mitre faces before fixing. A drop of adhesive at the joint resists shrinkage opening; fixing nails alone is not enough on external mitres.

4. Butt joints on long runs

Where a length of skirting runs longer than available stock, a scarf joint is used: two lengths joined at 45 degrees over a stud. The joint must land on a stud so both pieces can be nailed. Avoid butt joints mid-span.

5. Fixing

  • Nail through the skirting face, through the plasterboard, into the stud.
  • Nail size: 40 to 50 mm lost-head nails or brads. A 40 mm brad is the minimum to clear 13 mm plasterboard and achieve adequate penetration into framing.
  • Fixing centres: nail at each stud (450 to 600 mm centres). Add a lower nail at the floor line where the profile is deep enough.
  • At the base of the skirting, butt the board firmly down against the floor or the finished floor finish. Do not leave a gap to the floor: the skirting should sit tight. Where timber flooring is present, the floorboards need a 10 to 15 mm expansion gap to the wall; the skirting covers that gap and sits against the flooring surface.

6. Fixing to masonry or steel stud

On masonry walls, use a masonry nailer or construction adhesive (no stud to nail into). On steel-stud (light gauge) walls, 15-gauge galvanised brads will penetrate and hold in the steel track.

Steps: architrave installation

1. Set the quirk

The quirk is the setback between the inside edge of the architrave and the face of the jamb or reveal. Standard quirk is 5 mm (per Intrim Mouldings installation guide, verified 2026-05-08). Mark it around all three sides of the door or window opening using a combination square or a dedicated marking gauge. Some builders and joiners run 6 mm on wider jambs; the critical thing is consistency around the same opening.

2. Head piece first

Cut the head (top) architrave with 45-degree mitres at both ends. The short point of the mitre lands at the quirk mark at each top corner. Apply PVA to the mitre cuts before fitting. Nail the head piece to the jamb first, then to the wall lining.

3. Side legs

Measure each leg individually from long point to long point, allowing for the 45-degree mitre at the head and a square cut at the base. The base of the leg sits on or just above the finished floor or on a plinth block if specified. Cut and fit one leg at a time; walls are not always perfectly parallel, so measure each side independently.

4. Fixing

  • Nail into the jamb (reveal side of the nail line) and into the wall lining and framing (outer side of the nail line).
  • Nail centres: approximately 400 to 500 mm on the straight runs.
  • Adhesive: apply PVA at the mitre joints. For smaller profiles (up to about 66 mm width), construction adhesive to the back can eliminate nails on the reveal side; larger profiles require nailing for weight.

5. Window architrave

Windows are a four-piece set: two legs, a head and a sill. Sill returns at the internal face are typically mitred. The quirk convention is the same as for doors.

Timing: pre-paint vs post-paint debate

Most Australian residential builders fix skirting and architrave on primed boards after the wall topcoat is applied, then the painter returns for a final coat on the timber trim. This sequence:

  • Protects painted walls from chippy’s handling damage.
  • Allows the chippy to scribe and fill on a finished surface for a cleaner result.
  • Means the painter caulks and touches up trim in a single return visit.

An alternative used by some renovation carpenters is to prime and first-coat the boards off-site or on sawhorses, fix them to a primed wall, then apply only the final topcoat in place. This reduces in-place painting time but requires care not to damage the pre-coated surface during installation.

Pre-finished (fully coated) boards are generally not appropriate for new construction where nail holes need filling and caulking.

Tolerances and acceptance

These criteria are drawn from publicly accessible state guides. Paywalled HIA Guide values are tracked separately.

ItemAcceptance criterionSource
Gaps at mitre and butt joints (within 12 months)Max 1 mm visible from normal viewing positionVBA Guide to Standards and Tolerances 2015 (verified 2026-05-08)
Gaps at mitre and butt joints (after 12 months)Max 2 mm visible from normal viewing positionVBA Guide to Standards and Tolerances 2015 (verified 2026-05-08)
Face alignment at mitres and butt jointsFaces flush; misalignment visible from normal viewing position is a defectVBA Guide to Standards and Tolerances 2015 (verified 2026-05-08)
Fixing adequacyAdequate fixing in workmanlike manner; no loose or sprung lengthsNSW Guide to Standards and Tolerances 2017 (verified 2026-05-08)
Skirting-to-floor junctionSkirting butted tight to floor; no gap except where covered by quad/scotia over a floating floor expansion jointIntrim Mouldings installation guidance (verified 2026-05-08)
Skirting workmanship tolerances (HIA Guide)Per current HIA Guide to Materials and Workmanship: verified numerical value pending HIA member access. [HIA-054]HIA Guide (paywalled)
Architrave mitre tightness (HIA Guide)Per current HIA Guide to Materials and Workmanship: verified numerical value pending HIA member access. [HIA-055]HIA Guide (paywalled)

“Normal viewing position” in the state guides means standing upright at a normal occupancy distance (typically 1.5 to 2 m away under natural or artificial room lighting, not raking light). The VBA 2015 guide is under review as of 2024; check the VBA publications page for any updated edition.

Documents needed

  • Door and window schedule (types, sizes, jamb widths)
  • Floor plan (room dimensions, confirm stud centres)
  • Specification or finish schedule (profile, material, paint system)
  • Flooring type and installation sequence (floating floors need skirting last; sheet flooring is typically under the skirting)

Common holds

  • Painter not off site. Chippy arrives to fix skirting and the painter has not finished topcoating walls. Coordinate the sequence before booking.
  • Plasterboard not properly set to the floor line. Gaps or humps at the floor-wall junction cause skirting to spring off the wall face. The plasterer’s set coat must be tight to the floor or the chippy needs to pack.
  • Door frames not plumb. A racked jamb means the architrave quirk line is not square. The chippy can compensate on the leg cuts but it eats time and can affect the head mitre.
  • Profile not specified early enough. Skirting height conflicts with cabinetry kickboard height or with switch heights. The specification should be locked before second fix begins.
  • Movement after painting. On uncontrolled climate sites (no heating or air-conditioning running during fit-out), timber trim can shift after the painter completes the topcoat. Small gaps at internal mitres in skirting are a seasonal risk on solid timber profiles; MDF is more stable but can still move with extreme humidity swings.
  • Wet area material wrong. Standard MDF skirting installed in a bathroom laundry. Paint seals the face but cut ends and the back face wick moisture. Replace with MR MDF or primed pine in wet areas.

NCC position on skirting and architrave

Skirting boards and architraves are minor decorative elements fixed to the internal lining. They do not function as part of the wall and are not subject to the non-combustibility requirements that apply to internal linings of external walls under NCC 2022 Volume Two. This position is confirmed by the ABCB (verified 2026-05-08 at ncc.abcb.gov.au).

Note: NCC 2022 C1.10 (fire hazard properties) can still apply to elements attached to the internal side of an external wall in some building classes. For standard residential Class 1a construction, this is not typically triggered by skirting and architrave.

References

See also

Last updated: 2026-05-08. Verified: 2026-05-08. Quarterly review for currency.

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