10 Terms To Know Purlins Mullions C Sections What Does It All Mean

Posted by Donald Goodlad | Blog | April 13, 2021
10 Terms to Know: Purlins, Mullions, C Sections…what does it all mean?

Shed Talk | Making Sense of Product Names

While a shed or garage may seem simple, there are a lot of components and add-ons that can cause a bit of confusion for first-time owners.

We summarise ten of the more common shed parts to give you a better understanding of your garage construction:

Barge Caps

are used to cover the joins in your roofing. The long, narrow sheeting keeps your roof watertight and covers unsightly panel joins


are used in roofing to both attach panelling and create space for insulation and ventilation. While they aren’t heavy-load bearing, they also provide better roof integrity. These are often called top hats or top hat battens due to their profile shape.


In short, keep your garage dry. Used in different areas where rain may enter, they seal potential problem areas, such as around windows, doors and rooftop ventilation.

Fly & Strap Bracing

is used to reinforce your building. Fly bracing is used around roofing beams to give stronger attachment to roofing panels. Strap bracing comes in a roll and can be cut to length, making it incredibly versatile for timber and steel structures.


provide an anchor point for wall panelling. The lightweight, horizontal rail is generally used to give external wall panels something to screw onto, though can also be used internally.


sit over door and window openings to support everything above them, including wall panels and roofing. Without headers, your door frame could collapse.


are the vertical beams in doorways and windows that keep glass and panels in place and are often used to instal latches, handles and locks.


Similar to girts, secure external panels to the skeleton of your shed. The primary difference is that purlins are used specifically for roofing panels.


is a thin sheet, usually plastic, that provides extra waterproofing and insulation for your roof.

Web Cleats

in general are used to join load-bearing beams. fasten secondary, usually horizontal beams to the sturdy columns or down posts of your garage.

So there you have it – now you know all the terms and will be able to order your parts with confidence!

If you still can’t tell your purlins from your girts, and get the right advice for your needs.