Hennie Viljoen, marketing manager, MiTek Industries South Africa

Q: What has led to the trend towards pre-fabricated trusses in commercial and industrial environments?
Although there are several factors that have influenced the commercial and industrial roofing sectors, pre-fabricated timber roof trusses, as well as light gauge steel trusses have opened new avenues in terms of aesthetics and practical functionality, particularly in accommodating internal geysers, internal ducts and walkways, to name a few.

They are also proven to be the fastest and most cost-effective solution for roof framing in most cases.

Q: What are the advantages?
From a safety perspective, pre-fabricated roof trusses are engineered by adhering to the SANS codes. They are also manufactured off-site in a factory-controlled environment (except, in some cases, for ultra span), which translates into high-quality products that can be delivered to site with minimum on-site work alteration required.

Consideration is also given to the importance of minimising site waste, which has never been greater than in current times, leading the majority of house builders to prefer pre-manufactured building components.

Q: How sustainable are roof trusses?
In terms of environmentally friendly building materials, trusses are one of the most sustainable products. Both timber and light gauge steel are environmentally friendly, especially ultra-span light gauge steel, which is recyclable and therefore even more sustainable than timber.

Q: How adaptable are roof trusses?
Depending on span, pitch and depth, the possibilities are endless. In most circumstances timber trusses may appear to be the most cost-effective choice in the residential sector. However, when it comes to low-cost housing and large-span developments, light gauge steel trusses are more versatile and cost-effective.

In the residential sector, timber trusses are ideal for all types of roof structure applications, be those small or large spans. They are well suited for attics, creating extra space at a lower overall building cost – a benefit that is still underutilised in SA.

Commercially, timber roof trusses are suitable for most roof structure applications, up to 17m clear span, after which transportation can be a challenge unless using a site splicing option.

In the industrial space, it is possible to use timber in some instances, but this is dependent on truss span, depth/height and roof pitch.

Q: What load burdens are lessened through roof trusses?
With pre-fabricated engineered roof trusses, uniform or point loads can be added to certain trusses where, for example, a solar panel or geyser may be required. This ensures the load is catered and designed for in the relevant truss. This is crucial because should additional loads not be catered for, the truss/es may fail.

Q: How do you translate architecture into practical application?
Architectural building dimensions are entered into the MiTek software and the roof design is applied in the layout component. This provides a complete roof structure that can be exported to the engineering section of the software to ensure trusses are designed according to the SANS codes and other safety specifications.

The beauty of our design and engineering software is that it analyses the forces that pass through each connection based on the load cases submitted, and thereby provides the safest and most cost-effective solution.

Q: How advanced is the tech behind trusses?
The roof truss manufacturing industry demands faster results, cost-effectiveness and increasingly higher quality, which is why we never stop developing and improving our software. Following on from our current industry-leading software 20/20, we are about to release a new programme called Pamir – a significant software development within the roof truss industry in the past two decades.

Q: How will this software transform processes?
The roof layout, truss engineering, high-quality CAD output features and detailed reporting are combined into one integrated software platform. With Pamir we can edit building dimensions, move walls, include room additions and the likes, and watch the roof dynamically re-frame in seconds.

Pamir has a number of CAD functions that allow users to produce high-quality output, including building elevations, live cross sections, zoomed-in 3D detail and truss profiles – quickly and easily. A free, downloadable Pamir Viewer is also available, which can be installed on any Windows PC. This enables individuals in the supply chain (including architects, engineers and homeowners) to view the roof model and navigate the roof design in 3D. 

By Kerry Dimmer
Image: Janine Petzer

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