Durability - Protection

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

2. PRINCIPLES • Isolate timber from insects • Protect timber from water KEEP TIMBER DRY • Protect timber from sun/heat

3. ISOLATE TIMBER FROM PESTS • Barrier must be continuous – no direct path from ground to timber • Barrier edges must be easy to inspect • Seal any gaps • Types: • Monolithic slabs • Mesh barriers • Graded stone barriers • Reticulated chemical barriers

4. Stone barriers Chemical blanket ant caps ISOLATE TIMBER FROM PESTS Termimesh, granoguard ant caps, etc

5. ant caps ISOLATE TIMBER FROM PESTS Inspect timber regularly • barriers can be penetrated or bridged • inspect barrier for signs of penetration (galleries) • inspect wood for signs of infestation (galleries)

6. KEEP TIMBER DRY • Moisture essential for fungal growth • Moisture can cause swelling, cracking So… • Detail to prevent moisture getting into timber • Ensure ventilation to remove condensation and surface moisture • Maintain effective protective coatings

7. KEEP TIMBER DRY - posts • Protect important timber from ponded water • Elevate timber posts above water or wet surfaces • Detail connections to avoid trapped water Horticultural Training Centre, Mornington, Tas Photo: Greg Nolan CTBA, Bordeaux, France Photo: Geoff Boughton Marina residence, North Haven, SA Photo: Greg Nolan clearance ventilation

8. KEEP TIMBER DRY – other details • Protect timber from rain • good paint/Copper Napthanate seal • end-grain caps • roofs/verandahs • Use corrosion resistant fasteners Aboriginal Studies building, Cutin University, Perth, WA Photo: Geoff Boughton End-grain caps

9. Replaceable capping rail/ sloping KEEP TIMBER DRY – other details • Ensure water can run off exposed timber surfaces • grade or slope upper surface • Give timber good ventilation • Avoid condensation Forintek office, BC, Canada Photo: Geoff Boughton

10. KEEP TIMBER DRY simple detailing is better!  better  better Create details that have minimum opportunity to trap water!

11. PROTECTED H1/H2 30º EXPOSED H3 PROTECT TIMBERFROM SUN Hot sun can dry timber, cause shrinkage, cracking. Weatherboard house, NZ Photo: Geoff Boughton Nanga camp, Dwellingup, WA Photo: Geoff Boughton

12. PROTECT TIMBERFROM SUN • use top quality paints, stains, & water repellents • opaque systems work best light colours cooler, less weathering Devonport, Tas Photo: Geoff Boughton Hillarys, WA Photo: Geoff Boughton

13. MAINTAIN PROTECTION • repair & maintain paints, seals regularly • clear finish stains : 3 - 5 year maintenance • light colour paints : 7 - 10 year maintenance • see detailing for protection from water Devonport, Tas Photo: Geoff Boughton

14. EXPOSED TIMBER MEMBERS Timber can be used in exposed situations including high humidity and aggressive chemical environments Rotorua, NZ Photo: Geoff Boughton Mandurah Swimming Pool Photo: Greg Nolan

15. Clever detailing for exposed members High level of protection needed for critical structural members • Easily replaceable sacrificial elements • Use of durable timbers • Detailing to shed water • Effective coatings Replaceable face plate Lake footbridge, Finland Photo: Geoff Boughton

16. Top Bottom   Clever detailing for exposed members • Grade - fewest inclusions, splits, nicks in upper surface • Orientation - heart towards bottom • Size -minimise surface area

17. Clever detailing for exposed members • Glues - must use/specify exterior glues • Moisture content- • protect from moisture if possible • seasoned products close to equilibrium for most of Aust. • allow for shrinkage when using unseasoned timber Mooloomba beach house, Stradbroke Is., Qld Photo: Greg Nolan Horticultural Training Centre, Mornington, Tas Photo: Greg Nolan