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Durability - Hazards Biological/ Physical Hazards Weathering Fire Chemical TIMBER Species Natural durability of heartwood Maintenance ensures protection.

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Presentation on theme: "Durability - Hazards Biological/ Physical Hazards Weathering Fire Chemical TIMBER Species Natural durability of heartwood Maintenance ensures protection."— Presentation transcript:

1 Durability - Hazards 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

2 Hazards Anything that may cause deterioration of timber during service Reduce long-term performance Can counter the effects of hazards by Selection of appropriate species (Natural Durability) Treatment Detailing to minimize exposure to hazards Includes weathering, chemicals, fire No classification for these hazards – use appropriate detailing to minimize hazard impact Includes fungal, insect, marine organism attack Can classify according to Hazard Class scale

3 Physical Hazards Weathering - degradation due to weather rain sunlight Chemicals - timber performs well relative to steel/concrete resistant to degradation for pH>2 and pH<10 softwoods marginally better than hardwoods Fire - burning strength during fire insulation of walls prevention of spread

4 Preventable problems Weathering Kangaroo Point, Qld Photo: Geoff Boughton Plamerston, NT Photo: Geoff Boughton Marmion, WA Photo: Geoff Boughton

5 Biological Hazards Fungi Termite/borers Marine organisms Can classify according to Hazard Class scale

6 Preventable problems Fungi damage Marine borer damageTermite damage Photo: Geoff Boughton Horticultural Training Centre, Mornington, Tas Photo: Greg Nolan

7 Hazard Class ExposureService ConditionsBiological Hazard H1Inside above groundFully protected Well ventilated Borers only H2Inside above groundProtected from wetting, nil leaching Borers and termites H3Outside above groundModerate wetting & leachingDecay borers and termites H4Outside in groundSevere wetting & leachingSevere decay borers and termites H5Ground contactExtreme wetting, leaching &/or critical use Very severe decay borers and termites H6Marine waters north & south Prolonged immersion in sea water Marine wood borers and decay H6SWMarine waters south only Prolonged immersion in sea water Marine wood borers and decay

8 Natural Durability (Heartwood) Extractives and growth characteristics affect natural durability of timber species ClassDurabilitySpecies 1 Highly durableIronbark, Tallowwood, Cypress, Turpentine, Forest red gum 2 DurableSpotted gum, Blackbutt, River red gum, Western Cedar, Stringybark (yellow & white) 3 Moderately durable Brush box, Rose/flooded gum, Sydney blue gum, Silver topped stringy bark 4 Non-durableDouglas fir, Hoop pine, Radiata pine, Mountain ash/ Tasmanian oak, Unidentified timbers

9 Long-term Performance of Timber Can match natural durability class with environmental hazard to estimate long-term performance of untreated timber heartwood Natural Durability Class Heartwood Service Life (years) H1 fully protected H3 Above ground exposed H5 in-ground Class 150 + 25 + Class 250 +3015 – 25 Class 350 +158 – 15 Class 450 +5 - 8< 5

10 Hazard links to Treatment level Treatment levels have classes with same names as the Hazard levels H1 – lowest level treatment – suitable for H1 hazard environments – indoors, protected H2 – treated timber suitable for H2 hazard environments – suitable for all internal use H3 – treated timber suitable for H3 hazard environments – suitable for above ground external use H4 – treated timber suitable for H4 hazard environments – suitable for use in contact with dry ground H5 – treated timber suitable for H5 hazard environments – suitable for all in-ground use

11 H1 indoors, protected, ventilated Aged Care residence, Tapping, WA Photo: Geoff Boughton Wall panels Holybank Forest Centre Lilydale, Tas Photo: Greg Nolan

12 H2 all internal use, poorly ventilated eg. concealed wall frames and floor timbers

13 H3 above ground external use Marina residence, SA Photo: Greg Nolan Queenscliffe Jetty, Vic. Photo: Greg Nolan

14 H4 in contact with dry ground Play equipment, Geelong, Vic Photo: Geoff Boughton Hardwood walkway, Margaret River, WA Photo: Geoff Boughton

15 H5 all in-ground use, critical, subject to wetting pole house, Townsville, Qld Photo: Geoff Boughton Nanga Camp, Dwellingup, WA Photo: Geoff Boughton Logging bridge, Pemberton, WA Photo: Geoff Boughton

16 H6 Marine use – prolonged immersion in sea water Bussleton Jetty, WA Photo: Geoff Boughton Bussleton Jetty, WA Photo: Geoff Boughton


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