Durability - Treatment Biological/ Physical Hazards Weathering Fire Chemical TIMBER Species Natural durability of heartwood Maintenance ensures protection remains functional Treatment enhances durability of sapwood Fungi Termites / borers Marine Design Detailing minimises exposure to hazards

Treatment of timber in PROTECTED ENVIRONMENTS (H1 and H2) All species Secondary elements Primary elements All species Sapwood Excluded No treatment Sapwood allowed H1 treatment for lyctus-susceptible sapwood (NSW, Qld) H2 treatment in termite prone areas where specified Sapwood Excluded No treatment Sapwood allowed H1 treatment for lyctus-susceptible sapwood (NSW, Qld)

Treatment of timber in ELEVATED EXPOSED ENVIRONMENTS (H3) Primary and secondary elements Class 1 & 2 species Sapwood excluded No treatment Class 3 & 4 species Primary and secondary elements Sapwood excluded H3 treatment or better Sapwood allowed H3 treatment or better Sapwood allowed H3 treatment of sapwood

Treatment of timber IN-GROUND (H4 and H5) Primary and secondary elements Sapwood excluded No treatment Sapwood excluded H4/ H5 treatment Sapwood allowed H4/ H5 treatment Sapwood allowed H4/ H5 treatment Class 1 & 2 species Class 3 & 4 species

COMMON PRESERVATIVES Boron dipping

TREATMENTS LOSP timber mc unchanged dimensional stability clear limited water repellency may be difficult to glue Both are pressure treatment processes CCA ‘wet’ process timber needs to be redried greenish appearance

Pressure Treatment Processes  Drawing vacuum to suck out moisture  Holding vacuum for a time to allow moisture to move  Adding treatment chemicals in solvent  Pressurising vessel to force chemicals into wood  Holding pressure for a time to allow chemicals into wood Involves some or all of:  Placing wood in pressure treatment vessel  Removal of chemical  Removal of wood  Redrying

Penetration in pressure processes thin treated heartwood case Treated sawn section treated sapwood Treated round log treated sapwood Good penetration of sapwood Poor penetration of most heartwood

TREATMENTS For all chemically treated wood,  use and dispose of timber correctly  penetration of heartwood is limited  a little better penetration through ends