What’s the big deal?

Timber cladding is back. Using timber cladding on buildings over 10 metres in height is now possible again thanks to Fireshield WoodSafe-Exterior. In 2017 a restriction on the use of combustible external claddings was published in the New Zealand Building Code (C: Protection from Fire: C/AS2) which meant that the maximum height for timber cladding was restricted to buildings under 10 metres in height.

Gone were all the inspirational designs utilising timber facades. With the introduction of WoodSafe-Exterior to NZ, with its Type A certification, architects can use cedar in all forms of timber profiles, to once again bring beauty and design freedom back into our building industry.

What WoodSafe is

Fireshield WoodSafe-Exterior is a range of pre-finished, hard wearing, polymeric fire rated timbers specifically designed for exterior and wet area use. It is treated off-site and provides a certified Type A fire rating. The fire treatment is pressurised and heat treated into the fibres of the timber. This means there is no visible coating at all.

The treatment is durable for the lifespan of the timber (NZBC B2/AS1 requires 15 years, WoodSafe will outlast this). WoodSafe timbers can be stained or oiled, prolonging the life of the timber even further. It is the only timber that meets the requirements for external use above 10m or within a metre from the boundary.

WoodSafe uses only FSC and PEFC sourced timber and is considered untreated timber when being disposed of.

What WoodSafe is not

WoodSafe is not fake timber. Nor is it timber treated with ammonium phosphate. Ammonium phosphate systems are not weather tested and are susceptible to leaching. They are not suitable for exterior use and cannot be stained or oiled.

Let's get technical

There are two types of categories for cladding material:

• Cladding Type–A: Peak heat release rate (kW/m²): 100 / Total heat release rate (MJ/m²): 25
• Cladding Type–B: Peak heat release rate (kW/m²): 150 / Total heat release rate (MJ/m²): 50

The Acceptable Solution allows for Type A external claddings to be installed where the building is over 10m in height, and/or where there is less than 1m from the boundary. WoodSafe Exterior has been certified as Cladding Type A.

WoodSafe-Exterior is weather tested and is a heat-cured polymeric system which are the only fire impregnation systems currently approved for exterior use in NZ, weather tested to ASTM D2898 and EN16755. This means the fire-retardant properties are durable for the lifespan of the timber and never need to be maintained.

WoodSafe Exterior is leach resistant which is brought about by high temperature curing of the complex chemical system in the treated wood following impregnation and re-drying and achieves WPA and EN16755 Type EXT which is suitable for EN1995 Service Class 3 applications, the most severe category.

Why trust Fireshield WoodSafe-Exterior?

The team at Fireshield are known as specialists in passive fire products. The owner-Director is a registered fire engineer and the technical team consists of architects, designers, estimators and coatings specialists. They work with you from specification right through to building completion.

WoodSafe Exterior has been used in projects throughout Europe and America for over 30 years. With Fireshield’s technical support, designers across NZ are once again able to create beautiful timber facades and facade features on buildings over 10m high, or less 1m from the boundary.