Treatment of outdoor timber and decking
By Merensky Timber
With the dwindling supply of tropical hardwoods caused by major deforestation of natural forests , and the subsequent high prices of sustainably-sourced tropical hardwoods , there is a need for alternative sources of wood that don ’ t carry a hefty price tag – for the user ’ s pocket , or for the environment .
There are many alternatives that can be used for interior applications , but woods suitable for exterior use are a completely different proposition , as explored in this article .
Merensky Timber is researching exterior-use wood for various reasons . “ This allows us to utilise our fifth-generation Eucalyptus Grandis hardwood to its fullest extent and to provide existing customers with practical advice on the use of timber ,” says George Dowse , researcher at Merensky Timber .
“ We offer affordable , sustainably-sourced alternatives to tropical hardwoods , and place much emphasis on testing the various options in our South African climate , which differs considerably from the climatic conditions in many of the countries where large-scale tests are typically performed .”
WALKWAY EXPOSURE TESTING UNDER HIGH FOOT TRAFFIC CONDITIONS
Wood used in exterior applications such as decking , or walkways needs to be both strong and durable . One option for improving timber durability is to alter its physical properties through impregnation , heat treatment , or a combination of these processes . This works for certain applications but in most cases the overall costs end up as high as for tropical hardwood alternatives , and producers require large capital investments .
“ With this in mind , Merensky has turned its focus to surface treatments , and understanding what best suits our timber in various applications , so that we can give practical advice to our customers ,” says Dowse .
“ Our exposure testing covers the majority of South Africa ’ s commercially-available surface treatment options , including oil- , solvent- and water-based alternatives . Our testing also covers combinations of these as well as the use of additives such as waxes and UV-protective colour pigments .”
Dowse says the Merensky Research team has drawn up various conclusions through this testing , which form the basis of its recommendations to customers .
IMAGE BY RICHARD MCALL | PIXABAY
Not all treatments can be universally applied on all species and variations of wood .
22 AUGUST / SEPTEMBER 2021 // www . timberiq . co . za