LOCAL PROJECT
GARETH GRIFFITHS IMAGING
From left : Wayne Megaw ( Deloitte ), Kirsten Goosen , Mark Noble and Fran Ventura ( V & A Development Team ), at the roof wetting .
THE RIDGE : CLT FAÇADE
Cross-laminated timber ( CLT ) is classified as an engineered timber , made into panels and used in the construction of houses and commercial buildings . It is manufactured to specifications issued by the relevant authorities .
First developed and used in Germany , CLT is regarded as a fast-rising star in the use of natural materials in construction . The usage of CLT in Europe grew from the early 1990s and the first national specifications were issued by the Austrian authorities in 2002 . Usages included housing and for multi-storey buildings . As recently as 2015 , USA ’ s National Building Code incorporated CLT , followed by the International Building Code .
CLT is made by gluing together layers of solid-sawn lumber . Each layer of boards is usually oriented perpendicular to adjacent layers and glued on the wide faces of each board , usually in a symmetric way so that the outer layers have the same orientation .
An odd number of layers ( 3 , 5 , 7 , and so on ) is most common ( the Ridge uses 5 ), although even number configurations do exist . Regular timber is an anisotropic material , meaning that the physical properties change depending on the direction at which the force is applied .
“ The Ridge features double carbon savings by adopting CLT timber façade construction , making this mode well worth promoting in an age of climate change . Firstly , by choosing CLT , GHG ( COe ) emissions from concrete , steel and aluminium are avoided , all of which have high carbon footprints . And secondly , the CLT stores the carbon dioxide that was absorbed when the tree was growing and locks it away for as long as the building stands ,” explains Brunette .
Fast facts :
1 . Cross-laminated timber ( CLT ) is similar to Glulam , or ‘ shutterboard ’, but the timber grain runs in perpendicular directions in each layer , imparting great cross-direction strength to the product .
2 . CLT has become increasingly popular in Europe , the US and Canada . Building codes and specifications have been issued governing its use . It offers unique benefits to the environmental
performance of a building by way of lowering the building ’ s contribution to greenhouse gas emissions . 3 . CLT has a very long lifespan . 4 . At the Ridge , the CLT panels installed feature a sacrificial layer of timber skin on the outside , which will weather and produce beautiful colours over its lifecycle . It can theoretically be replaced , although it is unlikely that this will be necessary .
5 . CLT is a warm and people-friendly material . Inhabitants of the building will benefit by working in an office that features a low emission and low human toxicity material .
6 . The Ridge is one of the first commercial buildings in South Africa to feature a timber exterior and interior cladding .
PROFESSIONAL TEAM :
Professional Landlord / Developer Tenant Architect Engineering Team ( Comprehensive service ) Project Manager Quantity Surveyor Interior Architect Main Contractor Geo-tech engineer Landscape Architect Acoustics Ecobricks
Façade design , manufacture and installation team : CLT fabricator Façade – aluminium and glass fabricator and erector
Company V & A Waterfront Deloitte StudioMAS Arup Mace Smith & Co Paragon Interface GVK Siya Zama Core Geotech Planning Partners SRL V & A Waterfront
XLAM Geustyn & Horak
ACKNOWLEDGEMENTS :
Gareth Griffiths , materials scientist and professional sustainable construction writer .
www . timberiq . co . za // OCTOBER / NOVEMBER 2021 13