ABC Sheds Articles

Shed terminology explained

Shed terminology explained

A shed-building project is filled with technical terms and industry lingo, which can be confusing. In this article, we’ve outlined the most used terminology in the shed industry to help you make informed decisions and have a strong understanding when planning your shed project.

Structural steel shed


Apex refers to the top of the roof and is the highest point of the building. The apex joints are the point where the rafters are connected with an apex plate.


The bays are the distance between one portal frame to the next. For example, a shed with a length of 24m may consist of three 8m bays.


Bracing provides strength and stability and prevents movement. The amount and type of bracing required are determined by the wind loading, terrain, location, and design of your shed. 


Centre Support

A centre pole is a supporting post in the internal structure of a shed, supporting the rafters. This can be a cost-effective option if you have a particularly large span however it does impact the flexibility of storage inside. 


ClearSpan is the measurement across from one column to the opposite column without supporting posts in between. At ABC Sheds, our maximum standard clear span is 60m, using structural steel, I beam type framing and web trusses.


Columns run vertically from the foundation to the trusses, supporting the roof and walls. These also determine the wall height of the building.


Girts are metal purlins, running horizontally on the outside of the columns. The girts support the wall sheets and strengthen the building.

Hot dip galvanising

Hot dip galvanising is a thick and durable coating applied by immersing steel fabricated components in molten zinc/alloy. This coating provides an exceptional rust protection system and maximum durability.

Hot dip galvanising


Wind loadings and snow loadings are used to calculate the design requirements for your location. In extreme climates, the best building materials to use include timber and structural steel. 


Mullions are vertical columns in the middle of a gable end wall, sharing the load with the girts to support the wall sheeting.

Portal frame

Portal frames consist of columns and rafters bolted together at the knee joint and apex joint.


Purlins are metal battens that are fixed horizontally on top of the portal frame. This is what the roof sheets are fixed to. Purlins are made with roll-formed steel, which is flat sheet metal rolled into a C or Z shape.


Rafter beams create the roof frame, running from the apex to the gutter. They also support the roof purlins.

Roof pitch

The roof pitch is the slope or angle the roof falls from the apex to the gutter.

Shed doors

Shed doors

Shed doors include personal access (PA) doors, roller doors, and slider doors. A PA door is a standard-sized door that allows people to access the shed, a roller door features a continuous sheet that rolls up above the door opening, and a slider door opens horizontally along a track. 

Shed span

The shed span is the width of the building. At ABC Sheds, we can achieve a shed span of up to 60m.


A skillion roof has one flat surface, sloping in one direction. These are commonly used for lean-tos and awnings in sheds.

Structural steel

Structural steel is a special type of hot-formed steel, which has been roll-pressed at very high temperatures. This is thicker and fed through rollers, measuring anywhere from 5mm to 20mm thick.


Universal beams (UB), also known as I-beams, are structural steel beams formed in the shape of an I. These beams come in various shapes, sizes, and thicknesses.

Wind design speed/ Wind regions

Every building site has a wind speed determining the required building strength and steel specification. Wind design speed is measured in metres per second. For more information, read our article about Australian wind regions.  

Shed cladding

Shed cladding

Base Metal Thickness (BMT)

Base Metal Thickness measures the thickness of the metal before it has been coated with colour.

Total Coated Thickness (TCT)

Total Coated Thickness is the thickness of the metal sheet after it has been coated with paint. For more information, read our article comparing BMT with TCT.


COLORBOND® is a steel manufacturer in Australia, with a range of roofing, guttering, walling, fencing, and more. At ABC Sheds, we use COLORBOND® Trimwall and Trimclad for shed roof and wall cladding. 


Zincalume® is a steel cladding, available as roofing, flashings, cladding, gutters, fences, and more. At ABC Sheds, we use Zincalume® Trimwall and Trimclad for shed roof and wall cladding.

Types of sheds


Farm sheds

Farm sheds provide shelter for livestock and machinery, ensuring protection from the weather and predators. From farm machinery sheds to storage to shearing sheds, our farm sheds are designed for multiple applications. 

Hay sheds

A hay shed is used to store hay bales and handling equipment, protecting hay from the elements. With our flexible hay shed bay sizes, you’ll always have the right amount of storage space for your hay.

Yard covers

A yard cover is a roof designed to sit over an animal yard, offering protection from the elements and enabling good airflow and access. They can be used for feed pad covers, shearing area covers, milk station shelters, drafting yards, processing and tagging, and loading and unloading. 

Feedlot shelters

A feedlot shelter is a roof designed to sit atop a feedlot, providing shelter for animals and farm workers. At ABC Sheds, our flexible bay sizes allow us to cover any existing yards.

Grain sheds

A grain shed keeps your grain safe and dry all year round, with a concrete pad and a fully enclosed shed structure.

Fertiliser sheds

A fertiliser shed is a fully enclosed shed, keeping your fertiliser safe and secure. This means you can purchase fertiliser when the prices are lower and keep your farm well stocked at all times.

Cotton sheds

Cotton sheds are fully enclosed sheds designed to store cotton out of the elements. Common features include an overhead gantry crane, cantilever canopies, sliding doors or roller doors, personal access doors (PA), drive-through loading bays, and roof and wall insulation. 

Dressage arenas

A dressage arena is a space for equestrian riders, either covered or uncovered. At ABC Sheds, we specialise in fully enclosed arenas, allowing riders to use the arena all year round. 

Horse stables

Horse stables provide a sheltered and comfortable place for horses to rest. At ABC Sheds, we custom design every horse stable to suit your needs and can tie it in with your dressage arena.

Aircraft hangars

Aircraft hangars are designed to store planes and other aircraft safely and securely. This keeps your valuable assets out of the elements and allows you to complete maintenance. At ABC Sheds, we can also incorporate a mezzanine floor or residential space to suit your needs. 

Commercial sheds

A commercial or industrial shed is used for warehousing, manufacturing, retail, or other commercial buildings. 


A workshop is a multi-purpose shed designed for storing vehicles, machinery, equipment, tools, and workpieces. This provides a practical space to work on projects, with everything you need at hand.

Cola shelters

A cola shelter is a roof structure, designed to cover outdoor learning and play areas. This protects students from the rain or the hot sun. At ABC Sheds, our cola shelters can clearspan up to 60 metres.

Cyclone rated sheds

A cyclone-rated shed is designed and engineered to withstand strong wind speeds, according to the relevant wind zone. At ABC Sheds, we use fully fabricated frames and galvanised columns to maintain a strong building that complies with industry standards in high cyclone regions. 

Kit sheds

A kit set shed is packaged as a complete kit, pre-drilled and pre-cut according to the shed design. When the kit is delivered to the site, the structural elements can be lifted into place and fixed together more efficiently. 

At ABC Sheds, our shed kits come with footing cages, bolts, screws, downpipes, gutters, flashings, an installation DVD, and a clear set of instructions. 

Shed houses

A shed house is built inside the shell of a steel shed, fitted out as a residential space. The exterior of the building looks like a shed while the inside has lighting, plumbing, electrical, interior walls, and appliances.

Durakit sheds

Our Durakit range is a selection of pre-designed structural steel kit sheds, with stock available for delivery in under 4 weeks. View the complete range and pricing in the free Durakit brochure.

Custom sheds

Customised shed

A custom shed is built according to your needs and specifications with a completely bespoke design. This typically requires more design time. At ABC Sheds, we can customise your shed with various features, including:

  • Different bay sizes
  • Foam cell or wool blanket insulation
  • Roller doors or sliding doors
  • PA doors
  • Mezzanine floors
  • Windows
  • Vented ridges
  • And more.

With ABC Sheds, we’ll work with you until your new shed ticks all your boxes, simply reach out today or start planning your shed using our online shed builder tool.