Author: Lisa Smith
Corrugated metal sheeting has been a trusted building material in New Zealand for generations, from iconic farm sheds to garden studios and lifestyle buildings. Corrugated steel in particular is valued for its durability, low maintenance, and ability to withstand New Zealand's diverse climate.
When planning a timber shed or structure, many people spend time choosing colours, roofing materials and window placement, but often don’t give much thought to the orientation of the corrugated metal cladding. Should the sheets be installed vertically, as is more traditional, or horizontally for a more contemporary appearance?
The answer is that both orientations can perform exceptionally well when the building is properly designed and the sheets are correctly installed. The direction of the cladding doesn't directly determine whether your shed is weatherproof. Rather it influences the appearance of the building, the framing behind the cladding, installation methods and ongoing building functionality.
Weathertightness and Drainage
This is one of the biggest considerations for most people when deciding on the orientation of their sheet metal cladding. While the direction of the sheeting can play a small part, the most important factor for keeping water out of your shed or building will be the design and craftsmanship of the building.
Corrugated steel is inherently weather-resistant regardless of whether it runs horizontally or vertically. What determines long-term weathertightness is the quality of the installation.
Correct flashing details, appropriate fasteners and careful sealing around windows, doors and corners are all far more important than the direction of the corrugations.
Orienting the sheets vertically can make logical sense with regard to rainwater drainage. This is because the rainwater can run directly down the grooves under the flow of gravity. Installing the sheets horizontally does present slightly more resistance as the water now needs to flow across the grooves, rather than down them, however as with the vertical sheets, gravity is doing the majority of the work. Provided the horizontal sheets are installed with a slight slope rather than completely level, water will flow to the ground under the influence of gravity.
Outpost Buildings has a range of kitset sheds, livestock shelters, chicken coops and more that utilise durable Zincalume or Colorsteel roofing & wall cladding as horizontal sheets. The buildings are designed with weathertightness and drainage at the forefront, with flashings, galvanised fasteners and sloped roofs & walls to ensure the water flows off the buildings rather than pooling.
The Importance of Site Preparation
Proper site preparation is the one of the most important factors in preventing water from pooling around the base of your building, regardless of which way the corrugated sheeting runs. Even the most weatherproof steel cladding can be compromised if the building rests in a low-lying hollow or on uneven, poorly drained ground. Preparing a slightly elevated, level build platform, typically by clearing topsoil and laying a compacted gravel pad, allows rainwater to naturally drain away from the foundation rather than settling at the timber base.
By establishing a well-drained, raised site, you protect the bottom edges of your cladding from persistent ground moisture, reduce mud issues, and ensure your building remains dry and structurally sound for years to come.
Aesthetic Appeal
Installing the corrugated sheets vertically has often been seen as a default for agricultural buildings, garages and garden sheds throughout New Zealand. The uninterrupted vertical lines can make a building appear taller.
Horizontal corrugated metal has become increasingly popular in contemporary residential architecture and modern garden buildings. Running the sheets horizontally creates strong visual lines that can make a shed appear longer and lower, helping it blend naturally into landscaped gardens and outdoor entertaining areas. For some homeowners, this modern aesthetic can be a primary reason for choosing horizontal cladding.
Extra Strength for Relocatable Buildings
Beyond aesthetics, running corrugated steel horizontally offers a distinct engineering advantage for portable structures, by providing enhanced lateral strength. When corrugated metal is fixed horizontally across vertical wall studs, the rigid steel acts as a continuous structural brace for the walls. This dramatically increases the building’s shear resistance, helping it withstand the flexing and twisting forces that occur whenever a structure is moved.
Most Outpost Buildings kitsets are designed to be fully relocatable and are mounted on heavy-duty treated timber skids. This allows the buildings to be moved around whenever your lifestyle block or farm layout needs to change. The combination of the horizontal metal sheets and skid mounted bases help ensure the buildings are tough enough to be moved again and again without compromising their structural integrity.
Installation Considerations
Vertical sheet installation can be a simple process when planned in advance. Sheets often run from the bottom plate to the top of the wall with minimal joins, allowing rainwater to drain down the corrugations. The simplicity of the installation does depend on the building design, with the spacing of the vertical studs playing a key factor, as these serve as the primary attachment point for the sheets. The installation of horizontal timber pieces between the vertical framing studs may be necessary in order to attach the sheets to the frame and create overlaps.
Installing the sheeting horizontally can add to the strength of the building as the sheets can be attached directly to the vertical studs without the need for additional horizontal pieces. This does require the length of the sheets to match the spacing of the studs to avoid excessive sheet overlap.
Based on guidelines from BRANZ on Metal Wall Cladding, as long as the cladding is installed to code with correct overlaps and flashings, both vertical and horizontal orientations can be watertight. The choice doesn't come down to whether the building will be dry or damp, but rather to style and framing.
Purchasing a quality kitset building from a trusted manufacturer such as Outpost Buildings takes that guesswork out of stud spacing, sheet length or additional wooden bracing. Every Outpost kitset building is designed with durability and ease of construction in mind. Rather than spending days measuring and cutting framing timber and metal sheets, you receive a complete kit with clearly labelled pre-cut components and straightforward, easy-to-follow assembly instructions. This not only saves valuable construction time but also helps ensure the building is assembled accurately.
Final Thoughts on Orientation
The orientation of corrugated metal cladding has a noticeable effect on the appearance of your building, the framing design, the building functionality requirements and the installation process. A trip past the Big Dog and Sheep in Tirau, as many people have done on a Waikato road trip, provides a great demonstration of both vertical and horizontal metal sheet cladding used within a single design. When installed correctly using recognised New Zealand building practices, both horizontal and vertical corrugated metal provide excellent durability, weather resistance and long service life.
Ultimately, the best decision is the one that complements your property, suits your intended use, such as horizontal metal sheets for a relocatable building and is supported by quality construction.
By combining durable corrugated steel with a precision-engineered timber kitset like those from Outpost Buildings NZ, you'll have a building that's not only attractive but built tough to handle the demands of New Zealand's climate for many years to come.
