DESIGN POINTS What to consider.
Timber is a natural and renewable resource, providing an environmental advantage over common building materials. Timber will only perform within the limits of its natural properties. When specifying, it’s critical that the characteristics and properties of the timber are considered when determining how they will respond to the environment they are placed in.
Timber is a hygroscopic product, which means that it will absorb or lose moisture depending on the environment it is placed in. When timber is placed in a high humidity (moist) environment it absorbs moisture and expands, oppositely when timber is placed in a low humidity (dry) environment it sheds moisture and shrinks. Although the species used to manufacture Hurford’s Shou Sugi Ban has a lower radial and tangential shrinkage rate compared to hardwoods used for the same application, and is kiln dried, it is important that local conditions are taken into account when planning.
Consider the level of sun exposure, wind, rainfall and humidity in the area. Identify any possibilities of extreme conditions and alter the designs to suit. Allowances made at design stage can avoid potential problems later on. Our cladding profiles allow for 2.5mm expansion and 7mm contraction which is sufficient for normal conditions.
Leaching of tannins occur when timber is exposed to rain which may cause staining on surfaces in contact with a timber product. Leaching can be problematic when using a hardwood cladding product if not prepared and maintained correctly. Hurford’s charred timber cladding is produced using a conifer species, Callitris glaucophylla which doesn’t leach, avoiding any potential staining issues.
At design stage it’s important to detect any potential water traps or ventilation issues that will increase the chances of the cladding being affected by moisture. Hurford’s Shou Sugi Ban cladding profile and trim designs provide water diversions to decrease the chance of any sitting water, although, the Moisture Barrier System does not eliminate the need for good building practice and meeting the Building Code of Australia. An appropriate waterproof flashing needs to be installed to ensure the installation is watertight.
BUSH FIRE ATTACK LEVEL
There are six bush fire attack levels that are used to determine the appropriate construction to be applied to a development. Hurford’s Shou Sugi Ban standard production, Cypress is rated BAL-LOW. Most metropolitan and suburban blocks are defined as BAL–LOW. These sites have no special requirements as there is a very low risk of bushfire attack.
Shou Sugi Ban is also available in Durable Australian Hardwoods and BAL-29 Australian Hardwoods.
In many parts of Australia, the construction of new buildings and additions to existing buildings will be assessed with a BAL rating. The relevant Australian Standard AS 3959 provides for a range of Bushfire Attack Levels (BAL) for proposed construction. Read more by visiting www.as3959.com.au
It is well known that any timber left uncoated and exposed to direct or indirect sunlight will inevitably weather and grey off. Hurford’s Shou Sugi Ban Refined Architectural Cladding is no exception.
Shou Sugi Ban is supplied pre-oiled to assist in the protection from aging and colour change. During installation it is required you coat any sawn cut ends with Feast Watson Timber and Deck Stain, Black Japan.
Once Shou Sugi Ban Refined Architectural Cladding is installed, you need to apply a second coat of Feast Watson Timber and Deck Stain, Black Japan.
Periodic maintenance, including reapplying a fresh coat of Feast Watson Timber and Deck Stain, Black Japan is required to maintain the dark burnt texture of the product. Leaving the product unmaintained or uncoated will lead to the dark Shou Sugi Ban to naturally patina and age, changing its appearance. This change in appearance will not affect the performance of the product.
For more information on Feast Watson Timber and Deck Stain, Black Japan or to find a stockist please click on their website link www.feastwatson.com.au or call 1800 252 502.
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Q U E S T I O N S
Hurford’s are a Wholesaler and are unable to supply direct to builders and the public.
Please email us if you have a question or email your name, phone number, address so we will provide details of the closest Hurford’s reseller or if you request a sample piece.
Email: [email protected]