Durability
Because of their exposure to the weather, durability is an important consideration in deck construction:

• All timbers should be of class 1 or 2 durability. Suitable decking species are provided in Table 5.
  
• Cypress decking should be supplied with sapwood limited to 10% of the cross sectional area and 50% of faces or edges.
  
• Hardwoods with sapwood exceeding 10% of cross-sectional area should be factory treated with preservative.
  
• Sapwood should be avoided where possible in exposed applications.
  
• Posts should be kept clear of the ground via the use of galvanised metal post shoes or similar fitments.
  
• Connectors must be a minimum of hot-dip galvanised, however environments such as splash zones around pools, coastal regions or industrial corrosive environments, require stainless steel or silicon bronze connectors.
  
• Joints should be designed to minimise moisture entrapment using drained joints and flashings. Protective coatings can also be used to minimise moisture up-take inside the joint.
  
• A coat of water repellent preservative or oil based primer, plus a coat of surface finish, should be applied to the tops of joists and all surfaces of the decking. An alternative is to utilise proprietary capping, bituminous felt or coated capping systems. Where necessary this should be done prior to fixing and particular attention should be paid to ends of decking boards and the supporting timber framework.
   

Figure 4:Staggered deck board ends

 

Figure 6: Nailing at board ends

Figure 5: Nailing at intermediate locations