Step 1:Identify building projects under construction that may be affected by non load-bearing timber

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There are a number of key signs to look out for that could indicate a building may be affected by non load-bearing timber. These include:

• red markings on the timber (note: these don't always mean the timber is under strength)
• multiple colour markings or branding
• unmarked timber used in structural situations
• grade markings that have been obliterated or removed and replaced
• large knots in timber or other obvious defects in the timber (particularly if they are at the edge of the timber and exceed 50 percent of the width)
• visual signs of deformity to timber, particularly at the lower end of a chord of a truss
• No. 1 Framing timber used for roof trusses
• documentation identifying the truss and frame manufacturer that gives you cause for concern.

SG graded timber must be marked with certain minimum information at 1500mm centres. This includes:

• the identity of the grading organisation (represented by a number)
• the stress grade at close intervals along the length of each stick eg 'SG 8' or coloured paint markings along the timber (black for SG 8, green for SG 10)
• the grading Standard used (AS/NZS 1748 for machine stress-graded, NZS 3631 for visual graded)
• the date of production.

Figure 1: A model example of timber marking requirements.

Collect information as part of the identification process

BCA inspectors should identify, collect, and record in the consent file:

• the name and details of the original mill the timber was sourced from
• the manufacturer of the timber frames or trusses
• photos of the markings or branding (or lack of) on the timber
• photos of the timber's quality (such as any large or excessive defects such as large knots in the timber)
• what documentation exists on the timber frames and trusses (producer statements, frame and truss plans, specifications, etc).

Any other intelligence received from building suppliers, manufacturers, building practitioners or the public should also be considered, recorded and filed.