Preservative Treatments

Preservative Treatments 2017-06-19T00:30:57+00:00

Preservative Treatments

Evolution Forest Products is able to offer its range of timber based products with a range of treatments to extend the life of the product. Timber is treated with a preservative to improve the timber’s resistance to attack by wood destroying fungi and wood destroying insects. In other words, the timber’s durability is enhanced to a level which is suitable for the intended use. However, such “treatment” does not afford the timber protection against weathering.
Both untreated timber and treated timber used externally should be protected from the affects of weathering by the application of a coating or oil.
Levels of Treatment – Hazard Levels

There are six main levels of treatment and a number of sub-levels. These are called hazard levels and relate to the hazard to which the timber is going to be exposed.

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 (envelope treatment) used in dry situations south of the Tropic of Capricorn only
H2S Inside, above ground Protected from wetting, Nil leaching Borers and termites LVL/Plywood (glue-line treatment) used in dry situations south of the Tropic of Capricorn only
H3 Outside, above ground Subject to periodic moderate wetting and leaching Moderate decay, borers and termites Weatherboard, fascia, pergola posts (above ground), 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, pergola posts (in-ground) 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

Notes:

  1. Examples shown in this table are not exhaustive.
  2. Not all preservatives are suitable for all hazard levels.