SAWPA is an industry association which promotes the use of treated timber and treated timber products.
Understanding Timber Preservation.
A general introduction to the subject of wood technology and wood preservation. Knowledge of these fundamental factors can be of considerable assistance in gaining an appreciation of the value and importance of timber preservation and the selection of the most appropriate method of treatment. The growth of the Wood Preservation Industry has been one of the most important technical developments within the forest industry. The wide acceptance of preservation as an integral part of wood processing and utilisation has been a significant contribution to the use of what is the only structural raw material having a renewable and sustainable source of supply. There are timber structures still in existence after hundreds of years of service but there are fence posts which have rotted after only 18 months service.
This is due not only to a great variability in wood properties and our environment but also to the way in which the products are used. Wood suffers minor and gradual physical and chemical changes as a result of age. It is an organic material which can support the life of other organisms if the environment is suited to their growth and this, under certain conditions, leads to rapid breakdown of the wood. What are the circumstances in which wood is likely to be attacked by destructive agents and what measures should be taken to defeat them?
Most people can identify wood when they see it and can give names to the more familiar timbers in general use. However, much is taken for granted and relatively few may know timber in terms of a growing form of plant life or understand what structural variations produce the features characterising species which enable us to name them. The differences which exist between species are sufficient for us to realise that timber is a substance of greater diversity and character than materials such as steel and concrete. To enable the best use to be made of wood and to ensure the correct selection of the type best suited to any application, it is necessary to understand something of its structural form and characteristics and how these vary from species to species.
CCA (Copper-Chrome-Arsenate) is an industrial wood preservative and is widely used in South Africa. When applied to timber it enhances the durability by preserving it against biological deterioration such as insect attack (wood borer and termites) and fungal decay (rot). In South Africa only CCA Type C is allowed to be used as it is internationally recognised as the most stable and effective type, i.e. apart from its efficacy as a timber preservative, it successfully fixes to the lignocellulose material in wood. CCA may only be applied by industrial high pressure process from where the familiar term “pressure treated wood” hails from.
South African Standards SANS 1288, SANS 457-2/3 and SANS 753/4 specify the marking requirements for any preservative treated product that claims to comply with the respective Standards. The following information must be contained in the marking: a unique plant identifier or trademark, product certification mark, SANS standard designation, a hazard class, date or year of manufacture of poles…
A tree trunk has three main zones; the bark, the sapwood and the heartwood. Trees are basically triangular in shape and they gain height by growing outwards and upwards. At the start of each growing season, a new layer is added to the outside of the wood so that every part of the tree gets bigger – roots, trunk, branches and twigs.
An important consideration when building with timber is predicting how long the structure will last. Whilst insects, decay or rotting organisms and marine borers can all attack wood, some timber species have the ability to resist attack better than others. The natural durability of a species to resist attack by wood destroying organisms is an indication of how long that timber will last when it is exposed to a defined set of exposure conditions without any additional preservative protection. The natural durability of timber species varies, even so within the wood from the same species of tree, depending on whether its sapwood or heartwood.
According to NRCS VC 9092, The Compulsory Specification for Preservative Treated Timber, any preservative treated timber product claiming to be preservative treated must be branded as specified in the relevant SANS product standards. An important part of the brand is the Hazard Class, which indicates the service conditions to which the product is exposed and the level of treatment or level of protection that must be applied to the wood. The Hazard Classes have been defined as follows…
This Guidance Note addresses the importance of the use of properly preservative treated timber in the construction of substructures for timber decks and its compliance with the requirements as stipulated in the Building Regulations and relevant SANS Standards.
IN SOUTH AFRICA TREATED TIMBER IS BY LAW REQUIRED TO COMPLY WITH NATIONAL AND COMPULSORY SPECIFICATIONS AND MUST BEAR MARKING CONTAINING THE FOLLOWING INFORMATION
Preservatives for pressure treatment of wood guidance note
Exterior surface coatings play an important role in the final steps of the manufacture or construction and later, in the maintenance and renovation of wooden objects and structures. The consumer expects a reasonable level of performance from these finishes. However, the performance and hence the selection of an acceptable finish for an exterior wooden structure or product is influenced by several factors. These include wood characteristics, environmental exposure conditions, appearance of the finished product as well as durability, cost, ease of application, maintenance and renovation or removal of the finish….
This Guidance Note provides guidance to specifiers, designers, engineers, timber frame builders, or any other person or company regarding the correct use of treated timber poles for pilings or foundation poles in permanent buildings. This note gives information on the correct Hazard Class treatment needed for such poles as well as a remedial inspection and maintenance treatment program to be implemented by the relevant and applicable parties after installation. This note is in addition to and supports of all the requirements already specified in the relevant and applicable national and compulsory standards as well as the regulations related to the compliance and use of preservative treated timber.
There are two regulations in South Africa that apply to wood preservation. Both these regulations refer to compliance of SANS 10005, and in order for the reader, end-user, specifier, regulating authority etc. to fully understand the interpretation or intent of each regulation, one needs to read it in context with the relevant clauses given in SANS 10005, The preservative treatment of timber. SANS 10005 (previously SABS 05) is the code of practice that was developed many years ago as a guidance document on all matters pertaining to wood preservation, i.e. wood preservative types, processes, methods, treatment requirements, hazard classifications, reference to the relevant product specifications, handling precautions etc. SANS 10005 is commonly referred to by industry as “the bible” of wood preservation…
Safety precautions and warnings for use, handling and disposal of CCA preservative treated wood…
Building a wooden deck is a very popular project among DIYers, so here’s a deck to inspire and challenge you.
It seems that you always need an extra parking space at home, and carports are the ideal solution for a tight budget or a tight space. Here is a wooden design, that can double up as a structure for climbing plants, but is attractive enough to be left as is, too.
Finding storage space for all those things that don’t quite fit in the garage is easy when you have a garden shed. When you build one with durable pressure treated SA Pine you can count on some long-lasting protection for all those items you need to stash away and secure. This plan is adaptable to meet your storage needs. Three flooring options are specified and an optional ramp can be built to help get a wheelbarrow or mower in or out more easily. Inside, the 76 x 38mm stud wall will simplify the installation of shelves or hardware from which to hang tools.
With our ideal weather, why not put up a jungle gym in your garden for the children. This jungle gym is simple to construct and because of its rustic look, it won’t make the garden look messy, but will enhance it. But this doesn’t compare with how much the kids will love it.
Serve drinks around the pool with a poolside bar made from treated timber. The bar we are making has a roof section but you can choose to leave this out. See the photos of both kinds to see which is most suitable for you.