ANNUAL REPORT 09/10 - Forest and Wood Products Australia

36 | OPERATIONS
Assessing the suitability of roof system
designs for fire prone regions
Identifying designs incorporating timber trusses that
pass the Australian Bushfi re Attack Level standards
test will avoid potential loss of market in Victoria and
elsewhere as new standards are adopted.
Building houses in bushfi re-prone regions requires a
careful choice of materials; they must be affordable,
easy for local builders to source and work, and effective
in reducing the chances of the house catching fi re. In
partnership with other material suppliers, this project
assessed various sheet metal roof designs and materials
including roof trusses, battens, lining boards and fascia
linings. Roof ridges and roof valley prototypes were built
to compare timber, steel, plasterboard, cement-sheet
and insulation products. Each prototype was placed in
front of a furnace, and then radiant heat was measured at
strategic points inside the roof.
The project identifi ed successful designs that featured
timber trusses lined with a proprietary fi re-resistant
cement sheet, timber battens and a steel roof fi nished
with close-fi tting fl ashing and capping. These designs
passed the Australian Bushfi re Attack Level standards
test and are effective for fi re-prone regions and ensure
that timber trussed roof systems are still available to the
housing market for use in all regions of Australia.
PRA133-0809 An assessment of the bushfi re attack level
(BAL) performance of various sheet metal roof systems if
tested in accordance with AS 1530.8.2-2007 Section 16
(Flame Zone).
FWPA ANNUAL REPORT 09/10
Monitoring the performance of IBAs under real
time and accelerated testing regimes
Standards and performance requirements can slow the
uptake of new adhesives and understanding more about
durability testing can provide increased opportunities for
Australian industry to adopt advanced adhesive systems.
This project focused on the performance of isocyanatebased
adhesives (IBAs) used to bond Australian wood
species in Australian conditions. IBAs are an alternative to
phenolic-based adhesives used to produce engineered
wood products (EWP). There were three main areas of
investigation; a three year exposure test to monitor the
durability of IBAs; fi ve accelerated test methods; and the
hygro-mechanical responses (i.e. response to changes
in environmental conditions, particularly moisture) of
thin fi lms of adhesives. The wood species tested were
Radiata Pine, Victorian Ash and Spotted Gum.
The project has found that determining a correlation
between the three-year exposure test results and the
accelerated tests is diffi cult. Both the phenolic-based
adhesive and the IBAs performed similarly in the
exposure test, and there was no signifi cant adhesive
degradation associated with the Radiata Pine or Victorian
Ash samples. A longer exposure period may be required
for any trends to become more apparent.
PNB034-0506 The durability of isocyanate-based adhesives
under service in Australian conditions. The results from a
three-year exposure study and accelerated testing regime.
The samples at an exposure site in Darwin showing a
close-up of the loaded samples in the test rigs.