Best sheds for NZ conditions

If you are looking for a robust and long-lasting shed, environmental conditions are a key consideration. While some cheaper sheds may be suitable as a more temporary solution, they may not be able to withstand the wind, rain, snow, and salt-laden wind from seaspray around New Zealand. 

In this blog, we highlight the best solutions for shed building in New Zealand conditions, taking all the environmental factors into account. We also share the best sheds for these conditions, with a specific focus on wind loading, snow loading, and corrosion zones in coastal environments.

How climate conditions impact shed design

New Zealand experiences a vast range of climatic conditions, with temperatures ranging from subtropical to well below freezing. The majority of the country is also located close to the coast, resulting in moderate rainfall, frequent sunshine, and a higher level of salt spray. 

The weather is also prone to changing unexpectedly, with cold fronts and tropical cyclones blowing in from the ocean. As a result, your shed design and construction must account for a multitude of conditions. 

Wind loading

In New Zealand, wind zones are used to calculate the design load of building materials needed in a given location. They also help engineers and designers understand how to use those materials effectively. The three main categories to take note of are high, very high, and extra high.

In windy locations, the best building materials to use include timber and structural steel. These materials are robust and are fixed with bolted connections that easily withstand the extreme pressure of wind. 

Timber poles

Timber pole sheds are ideal for higher wind zones because they are generally between 175SED and 300SED (Small End Diameter in millimetres). Depending on the size of the shed, the poles are also firmly concreted into the ground between 1.2m to 2.0m deep so they won’t shift. 

Structural steel

Structural steel is an excellent product for high-wind areas and is widely renowned for its durability. Compared to roll-form steel, which is around 2-3mm thick and relies on the shape of its profile for strength rather than the thickness of the steel itself, structural steel is often 8-12mm thick and sometimes even thicker.

Snow loading

Some New Zealand locations are prone to high snowfalls, requiring engineering for snow loads. The snow load of a shed refers to the downward force on its roof, caused by the weight of accumulated snow and ice. If the snow load exceeds the building’s weight capacity, it may cause severe damage and even collapse. 

Timber poles work exceptionally well in high snow loaded areas, however, most pole shed designs can only achieve a clearspan of up to 6.0m. Alpine uses a structural steel rafter system in the roof that is securely bolted to the timber poles on the perimeter of the shed. This means that a larger span can be achieved of up to 20.0m without the need of internal centre supports, depending on the level of snow loading at the specific building site.  

You can find more information on the best sheds for high snow areas here. 

Coastal environments

• Corrosion zone A — Not applicable in New Zealand
• Corrosion zone B — Low risk
• Corrosion zone C — Medium risk 
• Corrosion zone D — High risk 

You can find more information on the best sheds for coastal areas here. 

Coastal grade cladding

To reduce the risk of corrosion and achieve longevity, we recommend using coastal-grade cladding for your shed. This cladding is coated with additional protective layers, meaning it will endure years of salt-laden winds and sand. 

Hot dip galvanised steel 

With a shed near the coast, we recommend hot dip galvanised rust protection for all steel components. This thick and durable coating evenly coats every surface, and will last a very long time. This rust protection system can only be used on structural steel as the galvanising baths are too hot for thin rolled steel and would severely damage lightweight portals.  This means that rolled steel sheds are not well suited for coastal environments as the salt laden wind can quickly corrode the thin steel. This can result in structural flaws over time. 

Birds 

If birds can perch in your shed, they will cause significant damage to the assets you store inside, with acidic droppings, lice, and nesting materials that increase the risk of fire. At Alpine, our Zero-Bird-Perch® rafters use a simple 'slot & bolt' system so there’s nowhere for birds to perch or nest. This means that the purlins sit flush between the rafters (not on top of the rafter) and due to the strength of the design, no apex braces or knee braces are required meaning that there are no areas in the roof space that birds can roost or nest. 

If you are looking for a shed that will comfortably handle the tough New Zealand conditions for generations, talk to the team at Alpine, they will ensure the shed is designed to your specific site requirements to give you peace of mind that your shed will last the distance, no matter where it is located. Our team will also handle the building consent process for you, making it quick, simple, and efficient. We know everything there is to know about kitset pole shed construction so let us take the load off you. 

Contact our team today or use our shed builder tool to plan your new shed and we’ll get in touch to let you know the estimate and any relevant requirements.