Choosing the right shed construction material is one of the biggest decisions you’ll make when starting your build. With so many factors to consider, it’s important to understand what will best suit your specific needs and environment.
There has always been a lot of discussion around what type of shed construction is better, steel sheds or timber sheds, and both systems offer unique advantages. However, there are key differences to consider before deciding what’s right for your project.
In this article, we’ll explore the pros and cons of each option and explain why Alpine’s unique system brings together the best of both.
Steel sheds
You’ll see steel sheds across New Zealand, from small garden sheds to large commercial and rural workshops. However, not all steel sheds are created equal. There are two common types of steel frame construction used today: cold-rolled steel and structural steel. They may look similar, but their performance and longevity differ significantly.
What is cold-rolled steel?
Cold-rolled steel is created by passing flat sheets of steel, usually 2–3mm thick, through rollers that bend them into shape. The resulting hollow sections form the portal frames of the building.
The pros of Rolled Steel
- Lightweight: The thinner steel makes the structure lighter and easier to handle on-site. This can reduce costs in terms of heavy lifting gear required, such as cranes or telehandlers.
- Rigid design: With knee and apex braces, cold-rolled sheds have good structural rigidity and can be designed to meet habitable building codes.
- Cost-effective: As the wall thickness of the steel is so thin, there is relatively little steel in the entire structure, which typically means cold-rolled metal sheds are usually cheaper to manufacture.
The cons of rolled steel
- Durability: The thin steel can be easily dented, and its strength relies on the shape of the profile rather than the steel’s actual density. A dented portal can easily compromise the structure.
- Rust: The thin steel cannot be hot-dip galvanised as it will warm and even melt due to the heat of the galvanising baths. This means the only option is to Electroplate the steel, which offers minimal rust protection, and when Tec screws are used, the heat from installation can strip the protective layer, leading to corrosion - especially near the coast.
- Bird proofing: The braces and open sections in these sheds create areas for birds to perch and nest, leading to an unhygienic interior and damage to anything stored inside due to the corrosive bird droppings.
- Noise: Because the portals are hollow, they amplify sound, making these sheds noisy during storms or when machinery is running.
What is Structural Steel?
Structural steel is significantly thicker, generally between 5–10mm, and is the material of choice for sheds that require maximum strength and lifespan.
The pros of structural steel
- Exceptional durability: Structural steel is extremely strong and doesn’t rely on shape alone. It resists dents and damage, making it ideal for long-term performance.
- Superior rust protection: It can be hot-dip galvanised, giving a much thicker, longer-lasting coating than electroplating. If rust does form over time, the steel can be grinded and painted; this isn't an option with the thin rolled steel.
- Design flexibility: Ideal for wide-span buildings, structural steel can achieve clear spans of 40 metres or more and easily incorporate gantry cranes or other heavy equipment.
The cons of structural steel
- Higher cost: Because of the steel’s thickness and weight, structural steel is more expensive to produce and transport.
- Heavy lifting required: Installation often requires cranes and specialised equipment, which can add to construction costs.
Timber Sheds
Timber sheds remain a popular choice throughout New Zealand for their durability, cost-effectiveness, and visual appeal. Most timber-framed sheds use timber poles with rough-sawn framing to create strong, reliable structures.
The pros of timber sheds
- Durability: Modern timber treatments allow timber sheds to last for decades. The poles can withstand knocks and perform very well in high wind and snow-loaded areas.
- Quieter internal environment: Timber naturally absorbs sound, reducing noise from machinery or bad weather, which provides a much more enjoyable working environment. This is a major advantage over metal sheds.
- Birdproof Design: Unlike many steel sheds, timber sheds typically don’t require knee or apex braces, leaving no gaps for birds to nest or perch.
The cons of timber
- Wet timber issues: Some suppliers use wet timber, which can shrink or warp as it dries. While this doesn’t normally cause structural issues, it can affect the final appearance.
- Limited clearspan: Standard timber beams can only span around 6m, while laminated (LVL) beams can reach up to 10m, depending on site conditions.
- Bracing limitations: Timber pole sheds can struggle to meet bracing requirements for habitable dwellings, so they’re best suited for workshops, storage, or farm buildings.
The Alpine System
At Alpine Buildings, we’ve taken the best features of both materials to create a unique, long-lasting solution. Our structural steel and timber-framed shed system combines structural steel rafters with timber poles and framing to deliver superior durability, strength, and value.
This combination allows for clearspans up to 21 metres, while maintaining the cost advantages of timber. The strength and rust resistance of our steel frame construction mean every Alpine shed comes with a 50-year building consent, double the lifespan of most roll-form steel sheds.
This design also includes a fully birdproof rafter system, with purlins set between the rafters to eliminate nesting areas. The result is a cleaner, more hygienic interior that protects your equipment and expensive assets.
To ensure quality, all Alpine timber is dried, graded and checked three times before it is sent out in a kitset. This attention to detail means you get straight, stable timber that won’t shrink, warp, or create gaps after installation.
Why Choose Alpine?
With three decades of experience designing sheds NZ wide, Alpine Building system has refined its process to deliver sheds that are durable, quiet, birdproof, and built to last. Our blend of structural steel and timber construction provides the best of both worlds.
If you’re weighing up steel vs timber shed options, talk to our team. We’ll help you choose the right design for your site and ensure your shed is an investment that lasts for generations.