Frame stage inspection for residential builds in Australia

What it is

The frame stage inspection is the structural hold point conducted once the wall frames, floor frames and roof trusses are stood, plumbed and braced, but before any internal lining, external cladding or insulation goes on. The frame must be fully exposed so every plate, stud, brace, strap and bracket is visible to the inspector. On a residential timber-framed build in Australia this inspection is mandatory under AS 1684 Residential Timber-Framed Construction, with cross-references to AS 1720.1 and the relevant NCC volume.

The inspection happens after first fix plumbing and electrical rough-in, so wall penetrations and chases are visible. Once the plasterboard goes on, the frame is gone for the life of the house.

What the inspector checks

Bracing

AS 1684 Part 2 specifies the required bracing units per metre based on wind classification, building height and roof type. The inspector counts bracing panels against the engineering bracing schedule, verifies each brace is the correct type (ply, metal angle, speed brace or diagonal cut-in), and confirms the fixing pattern. Missing tags on proprietary bracing products are a fail because the bracing units cannot be verified without them.

Tie-downs

AS 1684.2 clause 9.6.1 requires continuity of tie-down from the roof sheeting to the foundations. The inspector traces the tie-down path: roof batten to rafter or truss, rafter or truss to top plate, top plate to stud, stud to bottom plate, bottom plate to slab. Each link uses the fixing specified in the tie-down schedule. Strap lengths and nail counts at each end are measured against the table values for the wind classification.

Nail patterns

Plate-to-stud nailing follows the AS 1684.2 fixing tables. The default residential pattern is two 75 mm or 90 mm nails per stud-to-plate connection, with skew nailing or proprietary brackets for higher wind loads. Sheet bracing nail patterns are spaced per the bracing schedule, typically 50 mm at edges and 150 mm in the field for 7 mm ply bracing.

Timber grades and member sizes

Stud, plate, rafter and truss sizes are measured against the framing plan. Stress-graded timber carries a stamp showing the grade (MGP10, MGP12, F7, F8, F11) and the brand of the grader. The inspector spot-checks stamps on critical members. Engineered products (LVL, glulam, I-joists) carry their own product certificates matching the engineer's design.

Truss installation

Roof trusses are checked for spacing, bow, plumb and the truss fixing schedule from the manufacturer. Hip-end girder truss connections, which carry the highest loads, get particular attention. Damaged trusses must be repaired per a truss engineer's repair sketch before sign-off.

Penetrations and notching

Studs, plates and rafters notched or drilled by plumbers and electricians are checked against AS 1684.2 clause 2.4 limits. A 90 mm stud cannot be drilled with a hole larger than 25 mm at its central third, and notches in plates over 25 percent of plate depth typically require an engineer-designed repair.

Common defects flagged on site

• Missing tie-down at a single stud-to-bottom-plate location, breaking continuity for the entire wall.
• Wrong bracing type used where the engineer specified a higher capacity brace.
• Speed brace tags removed, leaving the bracing unit value unverifiable.
• Plumber-cut notch through a top plate exceeding the AS 1684 limit.
• Truss installed upside down or back to front.
• Lintels under-sized for the opening span and load above.
• Skew nailing used where proprietary brackets were required.
• Missing washers under M12 hold-down bolts at the slab edge.

A TradeLens scan flags the documentary gaps: missing truss layout, no engineer-stamped bracing schedule, untracked timber grade certificates.

Sign-off documentation

• Building surveyor or principal certifier frame inspection report, dated and signed.
• Engineer's bracing schedule and tie-down schedule, with site amendments initialled.
• Truss manufacturer fabrication drawings and engineering certificate for the truss set.
• Stress-graded timber grade certificates or supplier delivery dockets retaining the grade stamp evidence.
• Termite collar inspection at every penetration through the slab.

In NSW the principal certifier under the EP&A Act issues the record. In Victoria the registered building surveyor under the Building Act 1993 issues a Mandatory Inspection record. In Queensland the private building certifier inspects under the Building Act 1975. No internal linings, external cladding or roof covering can be installed until the frame inspection is signed off.