SPEAKER INTERVIEW: ROBERT MARSH

Robert Marsh will be speaking at The Big 5 Show next November. He shared with us some insight on what Purlins are and their importance in the MENA region. He is the Commercial Manager at voestalpine Metsec and will be talking on How designers can optimise purlin delivery at the Architecture Talks.

What is a purlin and how will it change the construction market of the MENA region?

Light-gauge cold-formed steel roof purlins were first introduced to the UK construction industry in the 1950’s, to replace heavier hot-rolled steel angle and channel sections. A purlin is a secondary structural member that spans between the primary/main steel frame to support the roof cladding. The use of purlins in the MENA region is already very well established with Metsec first supplying purlins from the UK to projects in the UAE as early as the 1980s. Since then the demand has increased exponentially with a number of different company’s setting up to manufacture locally to meet that demand. Over the last 30 year there have been a lot of advances made in purlin systems and how they are designed, which have led to cost/time savings and purlin strength allowing for long spans to be achieved. Not all these advances have been adopted in the region and are therefore not taken advantage of by designers and specifiers.     

How is the grade of steel important in designing and how can one ensure optimum selection of the same?

Steel grade is an extremely important factor. If an Engineer bases their design on a purlin manufactured from 450N/mm2 yield strength but the purlin supplied is manufactured from 350N/mm2 then this can have serious repercussions. While purlins manufacture from 350N/mm2 will be cheaper making them far more appealing to contractors, they generally have 25% less strength than the higher grade 450 which could lead to structural failures if the engineers design is based on strength not deflection limit, even if the purlin size and gauge of both is exactly the same. In reality if a 350N/mm2 purlin is substituted when 450N/mm2 has been specified the 350 purlin should have a higher gauge or web width to compensate. This is something that is sometimes over looked at costing stage. Engineers and Designers prefer to specify 450 because if offers a better strength to weight ratio than 350 therefore saving weight and ultimately cost of a project. The quickest and easiest way for an engineer to choose the optimum purlin size and purlin system is to use a dedicate purlin optimization software such as MetSPEC which was developed to be a quicker and more accurate alternative to using load tables.          

How can one reduce onsite installation time in an increasing manner?

Purlins rely on a number of other components called accessories to increase overall strength and resist twisting or sagging under load. By developing accessories such anti-sag rods and side rails supports to simply “ clip in “ without the need for tools, nuts, bolts or washers allows the steel erector to considerably reduce the installation time. We have also developed a way to color code and laser print pre-fix markings on the purlins which allows for easy identification and setting out on-site.

How can one eliminate human error and speed up purlin fabrication?

Working in conjunction with Tekla Structures over many years we have developed  intelligent macros within their 3D drafting software  that allow the user to rapidly model  the cold rolled purlins and accessories. The macros do not allow the purlin systems limitations to exceed and ensures the model meets our manufacturing requirements. Once a model has been created a digital file transfer of this data can be sent for validation and ordering purposes. This reduces time in producing and transferring details and eliminates errors earlier in the process.

What is light Steel Framing Systems (SFS)?

Benefits of SFS v Blockwork.   Steel Framing System ( SFS ) is a fast track modern method of construction that provides a solution that is considerably lighter than traditional methods such as blockwork. Manufactured from lightweight galvanised steel to form stud and track sections , SFS can be used in any type of construction project and support any type of external façade system and although rarely used in the MENA region it is now the prominent building method used in the UK, USA and other parts of the world. Benefits over blockwork include being more cost effective, lighter, quicker to build, less labour required, greener and more sustainable.

Why are you participating in the Architectural Talks of The Big 5 and what can visitors expect to learn at your session?  

To increase the knowledge of purlin optimization benefits, product and software innovations and BIM capabilities.  As well as learning more about and how to improve design on an established system such as purlins.  It’s also an opportunity to have an introduction session on SFS, a relatively new modern method of construction growing in demand in the MENA region.

About Robert Marsh -

Robert Marsh has over 20 years’ experience in the construction industry, assisting consulting engineers and architects to design and specify cold rolled purlin and light gauge steel framing systems, while also working closely with contractors and specialist sub-contracts.

In 2007 he joined voestalpine Metsec plc, the UK’s largest specialist cold roll-forming company, where he has been involved in some of the UK’s largest construction projects.

In 2016, voestalpine Metsec appointed him Commercial Manger to the Middle East to help support ongoing projects such as Midfield Terminal, Warner Bros World theme park and Expo2020, and to expand the company’s regional design and manufacturing capabilities.     

You can hear more from Robert Marsh on How designers can optimise purlin delivery at the Architecture Talks on 27th November, 13:00 - 13:45.