'Timber roof truss designer' now registered as professional designation

The registration of the professional designation officially took place late last year, when the SAQA board registered 'certified timber roof truss designer' as an additional professional designation on the NQF in terms of Section 13 (1) (i) (ii) of the National Qualifications Framework Act, 2008 (Act No. 67 of 2008) which states that SAQA must "recognise a professional body and register its professional designation if the criteria contemplated in subparagraph (i) have been met".

According to Amanda Obbes, national coordinator of the ITC-SA, “Thanks to the newly assigned professional status, professionals registered with the ITC-SA under the designation of timber roof truss designer will now receive due recognition in contracts documentation and will be recognised by statutory organisations as competent persons in their specific field of operation.”

Competencies required for membership

In order to secure and maintain membership status with the institute, timber roof truss designers must be able to demonstrate specific competencies in line with the category of roof structures for which they are permitted to design. The designer is to assume the manufacturer’s responsibility for translating a roof and truss design into an actual roofing solution that is both safe for the client and manufactured in a cost-effective manner by the fabricator.

In recommending material options for the roof design, the designer should demonstrate an understanding of the industry and have knowledge and understanding of design, terminology in roof engineering, the characteristics and properties of material used for structural design in roofing, the organisational and sector requirements as well as manufacturing tolerances and limitations. Quality control capabilities are also required as demanded by context.

The designer should be able to name and describe different materials used in roofing, identify structural properties, non-compliance of timber and steel, structural connectors and their application, and be able to differentiate between the advantages and disadvantages of the different structural materials, being able to understand the specification criteria.

Theory of structures

A comprehension of the theory of structures, to which roofs are designed to be able to carry all the applied loads, is essential. In this endeavour, the designer should be able to discuss triangulation of members in a truss and the transfer of the load to the foundations; differentiate between load definitions, application and specification; identify the difference between – and impact of – the different types of structural forces; identify the strength and impact of materials on a structure; and describe the methods of connections used in the design and manufacture of trusses.

The interacting factors in roof designs to deliver accurate estimates that do not compromise quality must be grasped, as should the fact that a functional roof structure is based on the key considerations of the impact of forces and weight distribution that can be handled by the supporting structure.

The designer should be able to construct or manufacture specialist timber formwork and trusses for roofing in line with safety legislation, the National Building Regulations and requirements, and based on specification drawings. The role of safety is crucial and understanding the implications of design modifications and industry convention to handle practical challenges is imperative.

The timber roof truss designer should be able to define the design responsibilities of the various role players within the organisation involved in the preparation, submission, review and approval of each truss design drawing and estimate. Contractual requirements as well as an appreciation for the impact of design and manufacturing inefficiencies and the handling of trusses are also competencies of this designation.

Designing green roofs

In promoting and designing green roofs, the designer should utilise design principles to optimise a green roof’s performance and align with client objectives, determine major functions and components of a green roof, be able to describe the characteristics and assess various advantages of different green roof systems, and be able to use an integrated design process in a project for maximum benefit.

“Members across all designations are to be confirmed as competent in the area of work for which they are registered. The institute shall ensure that Continuous Professional Development (CPD) opportunities are offered to these registered designations in a bid not only to drive and enhance competence in the sector, but to reduce consumer risk in enlisting the services of a registered professional,” says Obbes, adding, “Members that are found to have brought the ITC-SA and/or the industry into disrepute will be dealt with in terms of the ITC-SA’s disciplinary procedure and may even be removed from the register of practicing professionals.”

“The registration of timber roof truss designer as an additional professional designation in the portfolio of professions overseen by the ITC-SA will be of great benefit, not only to the institute and its members, but to the construction sector at large by contributing to skills development and professional service delivery in South Africa,” she concludes.