One of the great benefits of using Pryda Span floor trusses, in the $6 million Richmond custom-built six-unit complex, was the ease with which I met height restrictions on buildings imposed by Yarra City Council,” reveals Avanzi Constructions’ builder, David Grant.
“Because of its open-web construction, Pryda Span was in its element because we could pass all the services (electrical wiring, plumbing and air conditioning ducts) straight through, allowing us to maximize internal space height,” he said.
“If it had been alternative timber joists, we would have had to construct bulkheads for these services. Ceiling heights would also have had to be reduced to the minimum 2.4-metre requirement – as opposed to the 2.7-metre heights achieved in the upstairs living areas in all units, through the use of Pryda Span metal webs.”
Building height restrictions are critical in inner suburbs like Richmond, where substandard block leads to problems of overshadowing next-door abodes if strict council regulations are not adhered to when constructing multi-storey units.
“We are talking about six two and three-storey units with a common driveway on a 1000 square-metre block that previously accommodated two people,” Mr Grant said.
Faced with narrow equipment access, David Grant – who began the project (scheduled for completion in June) in July last year – decided to build outwards from the rear of the block so building materials could be more readily delivered and installed.
Dahlsens won the tender for the roof and floor trusses, delivering 900 lineal metres of Pryda Span to predetermined lengths as required.
“The longest span was 5.5 metres,” Mr Grant said. “However, Pryda Span is so light to handle there is a 15-20 per cent time saving in laying the product and passing the services, that more than compensates for any additional material costs that might be incurred.”
Another benefit of using Pryda Span was that, once it was in place, flooring could be laid immediately and internal stairs installed – providing a much safer work environment on the Richmond site.
However, it is the net installed cost benefits of its fully engineered open-web floor truss systems that Pryda is keen to promote – whether it be timber webs (Pryda Longreach) or metal webs (Pryda Span).
While the company acknowledges a possible material cost increase when compared with other flooring systems, installation provides significant labour savings and design advantages leading to overall cost benefits.
An interesting case study is the St Clair Park Village outside Auckland, New Zealand. Despite a six per cent increase in material costs by using Pryda Longreach floor trusses instead of solid joists, framing time was reduced by two weeks. This meant labour saving was 2.5 times the material cost increase resulting in an overall reduction of project costs.
In addition, open-web floor trusses have considerable design advantages that could result in reducing the requirement for costly support construction – for example, using long spans may eliminate the need for some internal load bearing walls.
Where architects and designers require greater scope, Pryda can provide extra long spans (up to 7.1 metres at 400mm depth using MGP12 pine) and large cantilevers with the ability to support high loads.
Pryda floor trusses also are ideal for sloping blocks and in some instances their use may eliminate or reduce associated excavation costs.
Each floor truss is customized for the job by the licensed Pryda Fabricator – including required stiffness, depth, timber grades and span – and computer designed using Pryda design software for optimal performance and cost and installation efficiency while eliminating waste.
For enquiries on Pryda floor truss systems please contact Pryda Australia on 1800 810 741.