KNOW YOUR MATERIAL

KNOW

YOUR MATERIAL

Understanding timber performance and the ‘where and why’ it should be specified is often clouded by misunderstanding and unfamiliarity with the material. As Rachel Pattison, Associate, Price & Myers points out, these misconceptions need to be challenged.

Having had a passion for timber engineering since university and had the opportunity to work on many successful timber projects, I am keen that timber continues to form a part of the UK construction market.

It is essential we use timber where practically possible to help address the climate emergency. With increasing pressures and targets from local authorities to become net zero there are requirements for design teams to submit whole lifecycle carbon emissions at planning stage and beyond. The use of timber helps drive down the embodied carbon of a building, when carefully considering sequestration and end-of-life scenarios. As I’m sure many others in the industry have recently found, the current challenges around the use of timber including fire, insurance and durability are proving difficult and sometimes resulting in timber being disregarded or omitted from schemes.

A common misconception from clients and insurers is that timber buildings are unsafe. We have found resistance from many clients in the past couple of years over the use of timber, with their reasoning largely coming down to fire and insurance concerns. This has been a detriment to a couple of projects where the use of timber would have been ideally suited. Whilst it is appreciated that new building regulations, and the behavior of mass timber in fire needs to be respected and properly accounted for through calculation or testing, I believe we need to do more to better inform our clients. Ensuring the right members of the design team are appointed with the appropriate experience is essential for this process.

It is welcoming to hear and read about current research into fire behavior of exposed mass timber buildings. On-going research like this is paramount to understanding the fire dynamics so the structure can be designed appropriately. This research will hopefully feed into new design standards and form a clear approach for the design of mass timber in the UK.

More recently there have been some discoveries on a few cross laminated timber (CLT) buildings where there has been water ingress and CLT panels have found to be rotten. This is a huge safety concern. Quite often the cause of water ingress is largely down to lack of maintenance and/or poor workmanship on-site. A better system needs to be in place for quality control on-site and sign off from approved inspectors, architects, and engineers. New technologies should be used to be able to monitor moisture content within cavities and concealed areas. Architects and designers should follow some simple best practice detailing rules to prevent potential water ingress and durability problems in the future. Looking at how other countries, including Norway and Canada, can implement mass timber on such a large scale, I think the UK can learn a lot from them. The industry needs to come together and work collaboratively to address these issues through research and knowledge sharing.

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01. Rachel Pattison, Associate, Price & Myers