Shed plans and quotes are full of technical terms, but you don’t need a degree in construction to understand them. This glossary explains the parts that make up a shed – from RHS (Rectangular Hollow Section) frames to portal frames, purlins, columns and more. By learning what each component does, you’ll be better equipped to choose the right design and communicate with builders.
Takeaway points
- Demystify the terminology: Learn what common terms like RHS, rafters and purlins mean so you can follow plans and quotes confidently.
- Understand the structure: Knowing the role of columns, portal frames and cladding helps you appreciate how a shed is engineered for strength and weather resistance.
- Make informed choices: Familiarity with components allows you to discuss custom features, durability and compliance requirements with your shed supplier.
Shed Structure
RHS – Rectangular Hollow Section.
Column – An upright Pillar – Internal Upright
Rafter – A beam Forming part of the internal framework of the roof.
Portal Frame – Consists of 2 Columns and 2 Rafters to make a complete section.
Purlin – Longitudinal structural members in a roof to support the roof cladding.
Girts – Horizontal structural members on the wall to support the wall cladding.
C Purlin – Sheet metal folded to look like a C that can be used as a roof purlin or wall girt.
Z Purlin – Sheet metal folded to look like a Z that can be used as a roof purlin or wall girt
Footing – A structural member that goes into bored holes in the ground. Footings are the first construction member of
the build. The footings are the anchor point for your entire shed.
Tek Screw – sometimes called a self-drilling screw. These screws drill their own pilot holes as they go.
Shed Extras:
Whirlybird – A Cylindrical dome that rotates in the wind and draws warm air from the shed.
PA Door – Personal access or man door
Skylights – Fibreglass light panel that replaces a sheet on the roof and allows light into the shed.
Cladding:
BMT – Base Metal Thickness – is a term to describe the thickness of the metal used not including coatings or paint. The thickness of your sheeting will affect the price of your shed. Thicker sheeting costs more.
TCT – Topcoat Thickness -total coating thickness is a term used to describe the overall thickness of a coloured or coated sheet steel like COLORBOND®. This figure includes the base metal thickness plus the paints or coatings.
Building Codes:
Class 10a – non-habitable structure that is classified as a shed, carport, or private garage.
Class 1 – Domestic or Residential building.
Shed Roof Styles:
Gable – A pitched roof that replicates a triangle.
Skillion – A flat roof that has a high point to a low point.
Barn – A larger Central Shed positioned between 2 smaller symmetrical awnings