In 2014, the roofing sector in West Australia earned a 33 per cent satisfactory rating, based on construction. This data is from the most recent inspection report of the WA Department of Commerce Building Commission.

1. Report: WA Earned 33 Per
Cent Satisfactory Rate for
Residential Metal Roof
Construction
Timberfix

2. In 2014, the roofing sector in West Australia earned a 33 per cent satisfactory rating, based on construction.
This data is from the most recent inspection report of the WA Department of Commerce Building
Commission.
The inspection was conducted to assess the durability of residential roofs and their resilience to wind
damage. It also aimed to check if the roofs met the performance standards set by the National Construction
Code.
Study on Satisfactory Roof Construction
The inspection consisted of a 12-point assessment, where the inspector examined the following aspects of
the construction of 123 sheet metal clad timber frame roofs of houses in Perth and South West:
 Tie-down corrosion
 Tie-down installation
 Timber roof batten within 1200mm of roof edges
 Timber roof batten connection in general roof areas
 Metal batten
 Rafter connection to the top plate
 Connections for the remainder of the roof
 Collar Ties
 Timber Truss
 Timber roof beams
 Steel roof beams
 Other sundry areas

3. The results showed varying ratings for the 12 general inspection points. The lowest rating is in relation to
corrosion (11 per cent), while the highest rating is batten installation (63 per cent).
Low Satisfactory Rating
From the relatively low satisfactory rating (33 per cent), it can be argued that the overall performance of
sheet metal clad timber roofs in WA dwellings is not impressive. The Commission attributed poor
performance to the following issues:
 Incorrect labelling of products
 Unavailability of conforming products
 Missing or improvised components
 Ineffective quality control
 Poor workmanship
Roof Construction Standard
For over 20 years, the Building Code of Australia (BCA) has been strictly requiring builders to construct roofs
in which timber and roof frames are firmly tied together and to the building structure. This can be done with
metal straps, propriety brackets, rods, bolts and appropriate screws. Compliance with the BCA can increase
the chances of roof resiliency, especially during strong winds and storms.
Based on discussions with roof manufacturers and builders, the Building Commission estimated that about
14,161 or about 60 per cent of houses in WA use sheet metal clad timber roofs in 2014. This can raise
concerns to thousands of home owners in WA. What can be done to ensure roof durability is regular
inspection, even during construction.

4. Sources:
http://www.timberfix.com.au/
https://www.commerce.wa.gov.au/sites/default/files/atoms/files/general_inspection_report_2016.pdf
https://www.commerce.wa.gov.au/announcements/improving-quality-control-roof-construction