A Little Treatment goes a long way: Treated Poles

November 20, 2014

Timber and wood are sensitive materials and thus need to be treated with preservatives to improve resistance to attacks by wood destroying fungi and insects. The treatment of timber enhances its durability to a level which is suitable for it's intended use. Furthermore treated poles should be protected from other external elements such as the weather through the application of coating or oil.

Treated Poles

There are a variety of ways in which poles can be treated according to the environment the pole is exposed to. Where some treatments protect timber against borer or termites, others protect against insects and decay. There are 6 hazard levels that will determine how your poles will need to be treated according to the level of potential exposure it will have:

Hazard Level Exposure Specific Service Conditions Biological Hazard Typical Uses
H1 Inside, above ground Completely protected from the weather and well ventilated and protected from termites Lyctid Borer Framing, flooring, furniture, interior joinery
H2 Inside, above ground Protected from wetting, Nil leaching Borers and termites Framing, flooring, etc., used in dry situations
H2F Inside, above ground Protected from wetting, Nil leaching Borers and termites Framing
H2S Inside, above ground Protected from wetting, Nil leaching Borers and termites LVL/Plywood (glue-line treatment)
H3 Outside, above ground Subject to periodic moderate wetting and leaching Moderate decay, borers and termites Weatherboard, fascia, pergola posts, window joinery, framing and decking
H3A Outside, above ground Products predominantly in vertical exposed situations and intended to have the supplementary paint coat system that is regularly maintained Moderate decay, borers and termites Fascia, bargeboards, exterior cladding, window joinery, door joinery and non-laminated verandah posts
H4 Outside, in-ground contact Subject to severe wetting and leaching Severe decay, borers and termites Fence posts, greenhouses and landscaping timbers
H5 Outside, in-ground contact, contact with or in fresh water Subject to extreme wetting and leaching and/or where the critical use requires a higher degree of protection Very severe decay, borers and termites Retaining walls, piling, house stumps, building poles, cooling tower fill
H6 Marine waters Subject to prolonged immersion in sea water Marine wood borers and decay Boat hulls, marine piles, jetty cross bracing

Types of Treated Poles

Creosote Treatment: One of the most common ways to treat timber is through the Creosote Treatment Process. Coal-tar creosote is valued in its toxicity towards fungi, insects and marine borer as well as its natural water repellant quality. It is commonly used to preserve and waterproof cross arms, pilings, telephone poles, transmission poles, marine pilings and fence posts. This is done using the "full-cell process" or "empty cell process".  

Copper Chrome Arsenate Treatment: Copper chrome arsenate (CCA) treated poles are timber that has been preserved with a substance containing copper, chromium and arsenic. This specifically prolongs the life of wooden poles that need to stand the test of time. This treatment method has been safely used for over 60 years having been invented in 1993. CCA treated poles have gained popularity due its low conductivity, low corrosion and combustibility resistance. This is both a cost effective and environmentally friendly method of treating poles as it prolongs the life of the pole, has no offensive odour and will not contaminate the soil surrounding the treated pole. Both of the above methods are available at the R&B Group. All R&B Group products meet the relevant SABS specification and ISO9001 standards, against pest, insect & fungal infestation. This ensures that you receive only the highest quality and professionalism for your treated poles.