Hazard Class

Exposure

Service Condition

Hazard

Example uses

H3

Outside above ground

Periodic moderate wetting and leaching

Moderate decay, borers and termites

Weatherboards, fascias, pergolas, framing etc.

H4

Outside inground

Severe wetting and leaching noncritical applications

Severe decay, borers and termites

Fence posts, retaining wall less than 1 m high, landscaping timbers.

H5

Outside inground with or in fresh water

Extreme wetting and leaching, critical application

Very severe decay, borers and termites

Piling, house stumps, power poles cooling tower fill, building poles, retaining walls more than 1m high

H6

Marine waters

Prolonged immersion in sea water

Decay and marine wood borers

Boat hulls, marine piles, jetty cross bracing, jetty landing steps.