TIMBER

                                                       TIMBER TREATMENTS   

SPECIES:

Native: rimu

Exotic: pine
Imported: kwila and balau

 TREATMENT:

 Types of treatment prevention from what? treated timber is to protect against damage by wood broing
insects or from moisture.

1.1 Protected from the weather, above ground Protected from the weather, always dry Borer Interior finishing timber –

H

see NZS 3602

H

but with a possibility of exposure to moisture

Protected from weather, but with a risk

of moisture content conducive to decay

Decay fungi and

borer

Wall framing –

see NZS 3602
1.2 Protected from the weather, above ground,
H3

(A

S/NZSZS 1604)

Exposed to the weather, above ground Periodic wetting, not in contact with

the ground

Decay fungi and

borer

Plywood – see NZS 3602

H3.

the ground

Decay fungi and

borer

Cladding, fascia, joinery

– see NZS 3602

H3.2

protected from the weather but with a risk

of moisture entrapment

Periodic wetting, not in contact with

the ground, more critical end uses

Decay fungi and

borer

Decks, pergolas,

external beams, posts

not in ground

H4

in fresh water

Ground contact, or conditions of severe or

continuous wetting

Decay fungi and

borer

Fence posts, landscaping

timbers not requiring

a building consent

H5

in fresh water

Ground contact, or conditions of severe or

continuous wetting, where uses are critical

and where a higher level of protection than

H4 is required

Decay fungi and

borer

House piles and poles,

crib walling, posts in

ground for decks,

verandas, pergolas
Exposed to the weather, in ground orExposed to the weather, in ground orExposed to the weather, above ground or1 Exposed to the weather, above ground Periodic wetting, not in contact withSTRENGTH APPREARANCE?

Aluminium is a poor insulator (metal conducts heat). The most common framing material, it is light, strong, durable and low maintenance. Choose aluminium framing products with thermal breaks (which place insulation between the interior and exterior part of the frame) or aluminium combined with other materials.

Timber is a good insulator, improving with frame thickness. Although a traditional framing material, it is less durable and should be treated and sealed for weathertightness to reduce swelling and shrinkage when exposed to rain and sun. It needs regular maintenance.

Composite timber-aluminium windows are better insulators than aluminium. Aluminium sits outside and is joined to the internal timber facing with a moisture barrier. They combine durability with a timber look for inside areas.

uPVC is a good insulator made from vinyl plastic. It is light, low maintenance and steel-reinforced for strength. Because uPVC is affected by ultraviolet light, durability needs proving in NZ conditions. Manufacture of uPVC uses petrochemicals and creates hazardous wastes  - see exterior building materials for more. uPVC use is growing in New Zealand.

Steel has largely been replaced by aluminium except for fire-rated windows and heritage building renovations.

Exposed to the weather, in ground orExposed to the weather, in ground orExposed to the weather, above ground or1S/NZSZS 16041.21.1