The robust case for CLT

As you may have suspected, I’m committed to engineered timber and believe it has a massive part to play in the future of the construction industry. The alignment of market need and political will is clear and this is why we are experiencing a step change in the adoption of offsite manufactured structural timber systems.

The new STA Advice Notes, freely available to members, have been developed for the collective good of our industry in a fast-developing business. KLH worked alongside other industry specialist’s B & K Structures, CCG OSM and Stora Enso to form part of the steering group, with additional technical support from TRADA and Milner Associates.

Produced under the banner of the ‘Robustness of CLT Structures’, the five technical papers provide guidance for the design, concept detailing and installation of panelised Cross Laminated Timber (CLT) building structures.

As engineered timber gains traction across the industry, more construction professionals are getting involved in projects using CLT as a core structural component. It is therefore essential that the design and installation teams together with the follow-on trades understand the building materials being adopted. The Advice Notes provide best practice principles and include guidance on installation to deliver robust CLT buildings.

The advice notes focus on core areas for the continuing evolution and growth of CLT building in the UK.

They look at durability, addressing the essential design and installation principles to support the development of robust structures, where durability is of course expected to be for the design life of the building.

CLT wall to foundation interfaces are another focus, including concept details on the interface of CLT wall panels and foundation support for heated buildings, whether housing, hotels, educational buildings or offices.

Over-arching principles for good practice detailing for the external CLT envelope are covered in another note, indicating strategies for controlling heat, air and moisture and providing indicative detailing to ensure structural durability.

Also a key area covered is construction process and sequencing for installation of CLT structures. This includes tolerances for fabrication and the protection of CLT during transport, storage and erection, together with a site inspection checklist.

The final topic is CLT structural design and manufacturing quality assurance, which incorporates advice on requirements for accredited third party assessment and certification for key components and elements, including ETA and CE marking.

From my professional standpoint, these Advice Notes demonstrate the STA’s commitment to raising quality.

It is essential to promote best practise principles across the wider construction industry to support the creation of robust structures that combine functional and load bearing characteristics, meet architectural aspirations, stand the test of time and help ensure a robust future for CLT-based construction in the UK.