Design For Durability
In the building industry every project will have unique design and construction requirements. Accurate and detailed documentation of the most suitable structural design will assist greatly in minimising construction problems and challenges and ensure projects are completed in a timely manner. The correct design will support the interpretation of the client brief and work within the constraints of the selected products, while taking into consideration the climate and weather.
MANAGING RISK
To correctly specify and utilise timber, particularly for exposed locations, it is critical to firstly assess the potential hazards for the specific application. A number of considerations should be thought about and discussed in the design phase to ensure the longevity of you timber while also mitigating the risk of potential design and construction flaws.
Consider the following:-
- Importance of correct design – It provides clear instructions on the intent, performance and construction of the project. Drawings and specifications should be clear and reflect the manufacturers’ product guides outlining the correct installation and use of products.
- Fit for purpose – Take into consideration the location and exposure to weather to help specify where timber can perform at its best. Consider where timber will be installed and how water and rain will run down the structure. Moisture is the number one issue when working with timber so good design to mitigate moisture build up wherever possible is very important.
- Working within the limits of timber – Being a natural product there are some constraints of what can be achieved but designing to the timbers strengths and durability status can create a stunning outcome. There are certain areas or designs where timber might not be the best choice and another product or a different species of timber may be more suitable.
- Orientation –Plan for the best orientation or exposure to maximise service and performance life. Realising that timber is a natural product prone to the elements means designing to keep timber not only visually appealing but also durable for years to come.
- Seasoning & weathering – Consider what sides of the structure would be satisfactory to install the timber on. Harsh weather with prevailing westerly winds may not be ideal for any natural product. Consider what finish you will apply to maintain the desired look of your timber. Be aware of different rates of weathering in different areas and orientations. It’s important to think about not only how the timber looks once installed but also 5, 10 and 20 years down the track.
DOCUMENTATION
Providing extensive documentation ensuring everyone from the
clients, to architects, to builders and all the other trades on site are on the
same page will ensure a smooth build. Detailed drawings and specifications will help eliminate installation problems. The specifications should provide clear instructions on the intent and construction requirements along with expected performance of timber used in the project. Specific attention should be given to the elimination or control of moisture being exposed to timber.
QUALITY OF CONSTRUCTION
The quality and reliability of fixings, detailing of connection points and coatings should match the timber selection so that the hazards are reduced to lessen the need for regular maintenance. Where possible, allow water to freely run off surfaces when it is exposed, and make sure the timber can dry out if it gets wet. Pay particular attention to areas of the home prone to taking on excess moisture and common building features that can cause problems with weather tightness.
Key factors:-
- Cladding cavity and flashing– A very important step in the quality of construction to ensure still air can be properly ventilated and any moisture that gets trapped can dissipate. Good ventilation is extremely important for the longevity of the timber cladding. Refer to our Cavity Set up behind timber cladding for further detailed information.
- Ventilation –An essential part of a timber deck design is to evaluate and eliminate stagnant moisture underneath the deck. Ground conditions, drainage and sufficient airflow are key factors to consider. For further information refer to our Decking ventilation and gap spacing guide.
- Finishing detail –Attention to detail for the small things can have a lasting effect in the long run. Specify robust, corrosive resistant fasteners and fixings made from a long lasting material with the correct finish or coating. Sealing of all end joins and grain will prevent moisture entry.
Designing for durability and ensuring the proper installation of timber products is extremely important to ensure that the home is protected from the harsh Australian climate and to maximise service and performance life.
Poor installation or design can cause timber products to fail and or have a much shorter service life. Ensuring longevity of your timber must start in the design phase and work its way through to the finishing touches.
