Building Components

Not too sure about the different components of your shed? Please click the + against each term below for a description of what each component is. If you cannot find the information you are looking for, please call 1800 821 033 to be connected with your nearest THE Shed Company outlet. 

An anchor bolt is used to attach objects, structures and columns to concrete on a variety of projects. Anchor bolts may also be known as “hold down” bolts, L-bolts, Chemset, sleeve or Tru-bolts. Their purpose is to secure the building to the foundation via the hold down bracket.

Apex refers to the top or highest point of the roof.

The apex plate or apex bracket joins the two rafters, forming the peak of the building.

A bearer is a member which supports the joists, for example in a mezzanine floor. Bearers run in an opposite direction to the floor joists, taking all the loads from the floor joist and transferring it to the columns and mid posts.

Bracing is important to the structure of your building. Bracing is determined by wind loading, terrain and the location of the building. Bracing is required on each and every building and provides strength and stability while preventing movement in the building. Bracing may take the form of Strap, Wire or Rod. The amount of bracing required will be determined by THE Shed Company and our Engineer.

Bridging are members fitted between and attached to purlins or girts to prevent twisting. They are supplied when the spans of the purlins and girts reach certain lengths.

Structural C and Z Section purlins and girts are used extensively in the shed industry across an array of applications where strong, reliable steel framing is used. To determine the size of C and Z sections the Engineer will need to take into consideration the span (width) of the building, the bays sizes and wind loading.

Capping is used to cover and protect gaps between roof cladding. Ridge Capping is used over the two runs of roof sheeting at the Apex of the roof. Barge Capping is used to cover the roof and wall cladding at the gable ends.

Cladding is a layer of non-load bearing material provided to protect and control the weather elements from infiltrating the building. Cladding is offered in an array of profiles to compliment both contemporary and traditional architecture. Built for long term performance, these profiles can be offered in high and low profile and corrugated.

A Column is a vertical C-Section used to support the rafters. Columns will vary in size depending upon the size of the structure. Columns join to the rafter via the knee bracket and may also be referred to as 'end wall columns' or 'intermediate columns'.

Corner flashing is a folded piece of steel in an ‘L’ shape which is placed vertically in corner situations where two walls meet to protect the building from weather. 

Rectangular or round downpipes are sections formed as a conduit for the disposal of rainwater collected in your gutters down to the ground. Each length of downpipe has one end larger than the other to allow for joining of different lengths. Downpipes maybe removed upon request. 

The eave purlin is a major structural component of the building. The eave purlin supports the roof, walls and gutter of the building and screws or bolts directly to the knee bracket or eave purlin bracket. 

Flashing is used to make your structure weather resistant and prevent water from entering the building. Flashing and capping are strips of metal formed to cover and weatherproof the edges of roofing and walls. Providing a significant aesthetic appearance to the building, corner flashing covers the gap between the side and end wall sheeting. Flashing also delivers the benefit of providing protection from vermin.

Girts are a horizontal structural section used to support a cladded wall. Depending upon their position, girts will be referred to as either 'side wall girts' or 'end wall girts'.

Side wall girts attach to the columns to support wall cladding and will vary in size and metal thickness.

End wall girts run between or over the end wall columns and are attached to the column via an end wall girt bracket. On most sheds the girts will overlap at columns.

A girt bracket joins wall girts to columns and roller door jambs.


Gutters are a channel at the eaves or on the roof of a building used to carry rain water. A functional product, they fit to the top of the side wall cladding and are supplied in a range of shapes depending on your area. They are available in a range of colours to coordinate to your facade.  

A pre-formed light gauge metal bracket that attaches at regular intervals to the fascia or wall of a building to support the guttering.

The header refers to a beam running across the opening of an open bay, personal access door or roller door. The header is used to attach sheeting and provide horizontal support above the door.

Hold down brackets may be an angle bracket or 'U' bracket, and are bolted to the web at the base of the column, into the slab or piers. Intermediate columns will have a 'U' bracket. 

Insulation is material used in the walls and roof of a steel building to reduce passage of heat through the cladding. An option to consider if you’re planning on spending significant time in the building, insulation provides a year round comfortable temperature solution. Insulation is easily installed in all applications and is ideal for commercial, residential, and rural applications. 

A jamb is a vertical side member for roller doors, PA doors and windows. The jamb bears the weight of the item and the wall girts. 

The Knee Plate or Knee Plate Bracket is a folded bracket which joins the columns and rafters together. These are either left or right hand brackets and are fixed to the 'web' and ‘flanges’ of the C Section.  

A mezzanine (floor) is an intermediate level between the floor and ceiling which provides additional floor space. Mezzanine flooring can double the available flooring space of your existing premises and can be used for additional offices or new storage area for your business/property. 

Mullions support the end walls, are longer than the columns and extend to the top of the rafters. Mullions may be referred to as end wall mullions (EWM). 

PA Door (Personal Access Door) is a door used by personnel for access and exit from a building. Available in an array of sizes and choose from the range of COLORBOND® colours including ZINCALUME®. 

A portal frame consists of two columns and two rafters, joined together by two haunch brackets and one apex bracket. Portal Frames may also include knee and apex bracing depending on the span, height and wind speed. Multiple portal frames create our steel kit sheds.  

Purlins are screwed to the rafters to support the roof cladding. They will vary in size and thickness according to the bay size and wind speed of the building.

A rafter is a C section that is designed to support the roof. Rafters will vary in size and thickness depending upon the size of the structure. Rafters join together via an apex bracket / plate. Also referred to as 'End Rafters' and 'Mid Rafters'.

A roof ventilator or Whirly Bird, is installed close to the apex of the roof to draw air from the building and assist with ventilation. With the use of natural air streams (wind) turbines draw out high temperatures from the roof and ensure there is proper air circulation in your house or building. A ventilator will help keep your structure dry and reduce air moisture and mould in winter while preventing heat build-up in summer. 

A skillion roof is a mono-pitched roof that slopes in a single direction. Available in either 6° or 12°, skillion roof sheds will have a high side and low side (when describing building height). 

Skylight sheeting is fibreglass sheet that can replace a single piece of roof sheeting to allow light into the building. A skylight is an excellent source of distributing natural light.

Top hats are used for the roof purlins and wall girts. Top hats varies in size with the main sizes used in the shed industry being: TH64075, TH64100, and TH120100. The size of Top Hat to be used will be determined by the engineer according to the size of the building and wind load on the building.

Vermin flashing is installed between the concrete and the wall cladding sheets to prevent vermin entering the building. It also prevents corrosion of sheeting which can be caused from direct contact with the concrete slab.

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