Specially designed triangular box trusses have been used for the first time to overcome access limitations for a covered courtyard in John Septimus Roe Anglican Community School at Mirrabooka in Western Australia.
The trusses were designed using Pryda Build by Rockingham-based Pryda fabricator WA Spantruss, assisted by Prydaâ€™s Market Development Engineer Bernard Kennelly and following a brief from the architects Brooking Design.
Costing $1.1 million, construction of the D Block enclosure (which began in January this year and is scheduled for completion in August) presented a comprehensive challenge because of its location between two adjacent brick structures and the fact that every effort had to be made to restrict noise transfer among all three spaces. This was due in no small part to students undertaking a variety of activities in all areas with potentially up to 190 students using the spaces at any given moment.
Brooking Design is a noted specialist and award winner in school architecture with currently more than $10 million worth of projects either in design or under construction. Recently recognised for its work on the John Septimus Roe Kindergarten in Beechboro WA, by the Western Australian chapter of the Australian Institute of Architects, the Australian Interior Design Awards and Dulux Colour Awards, Brooking Design has used Pryda fabricators to solve complex truss design issues in the past.
The John Septimus Roe Anglican Community School was no exception, with the Nordic style courtyard design needed to match the previous kindergarten project Brooking Design had completed at the venue â€“ and the use of timber, insulation and natural lighting essential to meeting sustainability requirements.
WA Spantruss designed and supplied 9.2-metre long double parallel girder trusses for each of the 14 portals or panels needed to cover in the courtyard â€“ supported 4.8 metres above the ground by laminated LVL timber beams.
The timber columns, trusses and plywood forming the construction of roof and walls have resulted in a significant reduction in noise transfer.
The use of the triangular box construction (where two truss sections were connected together) means the roof can not only include light panels but it also is aesthetically pleasing and an interesting geometric form that bathes the internal space in diffused sunlight.
When combined with the padding between the double timber stud wall frame, the triangular box trusses not only significantly reduce reflected noise, but also provide improved insulation.
Use of the triangular box sections (comprising large numbers of the same, simple and cost effective shaped truss) was critical to the successful completion of the project because it resulted in a lightweight, rigid structure that only needed common fixings, quick and easy to use on site without any special skills required.
Because access to the site was so confined, the triangular boxes could easily be formed on site by two or three carpenters and then lifted into place by a very small crane that quietly manoeuvred between the timber columns.
With the project scheduled to be completed in August, the triangular box trusses have significantly contributed to achieving the projectâ€™s objectives of restricting noise transfer, access to natural light, improved insulation qualities and speedy onsite erection.