Overview of Timber Treatment for Radiata pine and Douglas fir

 

For full details check B2/AS1

Where timber treatments are used
LevelSpeciesBuilding Element
Floor framing protected from weather but exposed to ground atmosphere
H1.2 Radiata pine
Douglas fir
Jackstuds, subfloor braces, wall plates, floor joists to the subfloor, blocking, walings and battens, nogs and diagonal boards
H1.2 Radiata pine
Douglas fir
Interior solid wood flooring for ground floors
Enclosed roof framing and trusses
H1.2 Radiata pine
Douglas fir
Sarking and framing not protected from solar-driven moisture through absorbent cladding materials
H1.2 Radiata pine
Douglas fir
Enclosed flat roof framing and associated roof members
H1.2 Radiata pine
Douglas fir
Enclosed skillion roof framing and associated roof members
H1.2 Radiata pine
Douglas fir
Valley boards and boards supporting flashings for box gutters, roof penetrations and upstands to roof decks
H1.2 Radiata pine
Douglas fir
All roof trusses, including gable end trusses, roof framing, ceiling and eaves framing, purlins and battens
Enclosed wall framing protected from the weather
H1.2 Radiata pine
Douglas fir
Framing and other members within or beneath a parapet
H1.2 Radiata pine
Douglas fir
Framing and other members within enclosed decks or balconies (see H3.2 for cantilevered decks)
H3.2 Radiata pine Framing and other members within enclosed cantilevered decks (including joist trimmers, nogs and blocking)
H1.2  Radiata pine
Douglas fir
Framing and other members supporting enclosed decks or balconies (including for cantilevered decks)
H3.1 Radiata pine Battens used behind cladding to form a cavity (H3.1 treatments can be either solvent-based or boron. H3.1 boron treatments supplied grey primer-painted)
H1.2 Radiata pine
Douglas fir
All other exterior wall framing and other members including exterior and boundary joists
Internal Wall Framing
H1.2 Radiata pine
Douglas fir
Internal walls
Mid-floor framing
H1.2 Radiata pine
Douglas fir
All mid-floor framing, including boundary joists, ceiling framing and ceiling battens and double top plates
Interior flooring
H1.2 Pinus species
Douglas fir
Interior flooring
Other framing
None Radiata pine
Douglas fir
Wall framing and roof framing (including trusses) protected from the weather, in unlined and unoccupied farm buildings and outbuildings, except buildings with high internal humidity, such as saunas, spas etc
H3.2 Radiata pine Framing exposed to the weather and above ground
H4 Radiata pine Framing, such as fence posts and landscape timbers, that is exposed to the weather and is in contact with the ground
H5 Radiata pine Framing, such as house piles, poles and crib walling, that is exposed to the weather and is in contact with the ground.

Note 1: For structural use of other species, refer to NZS 3602:2003 Tables 1 and 2.

Note 2: For non-structural use of radiata pine, Douglas fir and other species, refer to NZS 3602:2003 Table 3.

Note 3: A higher treatment level also satisfies the level specified in this table.

This information is published by the Ministry of Business, Innovation and Employment’s Chief Executive. It is a general guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case. Expert advice may be required in specific circumstances. Where this information relates to assisting people: