Ring a shed supplier for a quote and within about thirty seconds someone will ask what wall height you want, whether you’re after a skillion or a gable, and how many PA doors you need. If none of that means anything to you, the conversation gets harder than it needs to be.
None of it is complicated once someone explains it. Here’s the language, grouped by where you’ll run into it, so you can talk to us, your council and your builder without guessing.
How Sheds Are Measured
Sheds are quoted as three numbers, and mixing up the order is the most common mix-up there is.
Span. The width of the shed, measured across the gable end. It’s the direction the rafters run. When someone says a 9m x 12m shed, the 9 is usually the span.
Length. The other direction, made up of a number of bays. Length is the easy dimension to change because you’re just adding bays.
Wall height. Measured from the slab to the top of the wall, not to the peak of the roof. This is the number people underestimate most often, especially anyone parking a caravan.
Apex height or ridge height. The height at the highest point of the roof. On a gable shed it’s noticeably taller than the wall height, and it’s the number council will look at against any height limit.
Clear height. The actual usable height under the door opening or under a beam, once you’ve allowed for framing. Always the number to check for vehicle clearance.
There’s a diagram on our quote page showing how dimensions are read, which saves a lot of back and forth.
The Frame
Portal frame. The main structural unit of a shed. Two columns with rafters over the top, joined into a single frame. A shed is a row of these standing in line with sheeting wrapped around them.
Column. The vertical member. The post, in plain English.
Rafter. The member running from the top of the column up to the apex, carrying the roof.
Bay. The space between one portal frame and the next. Shed length is bays multiplied by bay width. Closer bays mean a stronger building, which is why sheds in high wind areas often have more frames in the same length.
Clear span. A shed with no internal columns, so the whole floor is open. Everything we supply is clear span, which matters if you’re driving machinery in or fitting out a workshop.
Girts. Horizontal members running along the walls between columns. The wall sheeting screws to these.
Purlins. The same idea on the roof, running across the rafters. Roof sheeting screws to these.
Knee. The joint where the column meets the rafter. Also called the haunch.
Apex. The top joint where the two rafters meet on a gable shed.
Mullion. A vertical member in an end wall or around an opening, supporting girts and framing up doors and windows.
Bracing. Steel strap or cable running diagonally through the roof and walls to stop the building racking sideways under wind load. Not optional and not the place to save money.
Roof Shapes and Pitch
Gable. The traditional two sided roof meeting at a ridge. Sheds water both ways, gives you height in the middle, and looks like what most people picture when they think shed.
Skillion. A single slope from one wall to the other. Cheaper, lower, and good where you’re working under a height limit or want a flatter modern look.
Mansard or Quaker. The barn roof. A steeper lower section with a flatter section above, which is what gives American barns their shape and creates the usable space upstairs.
Roof pitch. The angle of the roof, in degrees. Ours are available in 11, 15, 22, 30 and 45 degrees, plus mansard and Quaker. Steeper pitch means more headroom, better water runoff and a taller looking building. It also means more steel and a higher apex height, which can matter for approval. Our roof pitch page shows what each one looks like.
Eave. The lower edge of the roof where it meets the wall line.
Overhang. Roof extending past the wall. Shades the walls and keeps rain off doorways.
Barge. The finishing capping along the sloping edge of a gable end.
Flashing. The folded steel that seals joints, corners and junctions. Small parts, big job. Most shed leaks are flashing problems, not sheeting problems.
Gutter and downpipe. Included in the kit. Where the water goes after that is a site question, and often a council one.
Doors and Openings
Roller door. The curtain style door that rolls up into a drum above the opening. The usual choice for vehicles. Quoted as width x height of the opening.
PA door. Personal access door. The normal hinged door you walk through. Cheap to add and worth having so you’re not lifting a roller door every time you need a screwdriver.
Sliding door. Runs on a track across the outside of the wall. Common on farm sheds and barns where the openings are wide.
Open bay. A bay left unsheeted at the front. Standard on machinery sheds where you want to drive straight in.
Awning or lean-to. A roofed extension off the side of the main building, either open or enclosed. Cheap way to add covered space without extending the shed itself.
Cladding and Steel
Cladding. The sheeting on the roof and walls. Different profiles have different looks and different spanning ability. Our cladding options page runs through corrugated and the flatter panel profiles.
COLORBOND steel. Pre painted steel from BlueScope, available across the full colour range. Our colour page has the lot.
ZINCALUME steel. Unpainted coated steel with the silver finish. Cheaper than Colorbond and very durable, but you don’t get a colour choice.
Sarking. The foil blanket sitting under the roof sheeting. Reflects heat and, more importantly, stops condensation dripping off the underside of the roof onto whatever you’ve parked below.
Fixings. The screws. Sounds trivial until you’re in a cyclone area, where spacing, washer type and fastener spec are all engineered rather than assumed.
Shed Types You’ll See Advertised
Garaport. A garage with an attached open bay under the same roofline. Lock up one side, park the boat or the trailer under cover on the other. See the garaport range.
American barn. The mansard roof shape with a raised centre section and lean-tos either side. Stacks of usable height in the middle. Ours are on the barns page.
Rural lockup. A farm style shed with enclosed bays for anything you don’t want sitting in the open.
Skillion garage. A garage with the single slope roof. Lower profile, often the pick where a height limit is tight.
Engineering and Compliance
Wind region. Australia is split into four regions, A to D, under AS/NZS 1170.2. The region sets how hard the shed has to be built and it moves the price. We’ve got a full guide to wind regions if you want the detail.
Terrain category. How exposed your particular site is. A bare paddock is treated differently to a block surrounded by houses.
Importance level. How serious the consequences are if the building fails. Most domestic sheds are level 2.
Cyclonic rating. Region C and D builds, with heavier framing, cyclone washers and cladding tested for repeated loading. That’s what the cyclone rated range is.
Engineered plans. Site specific drawings and certification for your shed at your address, which is what council wants with an application. Not a generic set.
ShedSafe. An accreditation run by the Australian Steel Institute confirming a supplier’s kits are engineered to the relevant standards. We’re accredited, and it’s worth asking anyone you’re quoting with whether they are.
Class 10a. The building classification for a shed or garage under the National Construction Code. A non-habitable building. A house is Class 1a, which is a different build entirely.
Slab and Site Words
Slab. The concrete floor you pour before the shed goes up. You supply it. Thickness and reinforcement come from the engineering, not from a rule of thumb.
Edge beam or thickened edge. The deeper section of concrete around the perimeter that the shed bolts into.
Footings. What holds the building down. On a shed, uplift usually governs, so the footings are there to stop the whole thing lifting rather than to stop it sinking.
Anchor bolts and cast-in brackets. The two common ways of tying the columns to the concrete. Which one you use depends on the engineering and how your builder works.
Cut and fill. Levelling a sloping site by cutting into the high side and filling the low side. Fill needs compacting properly or the slab suffers for it.
Erector. The crew who put the kit up. We supply the kit, and we can point you to builders we work with in our area.
Putting It Together on a Quote
Once you’ve got the language, a quote reads quickly. Span, length and wall height. Roof style and pitch. Door sizes and positions. Colours for roof, walls, gutters and trim. Wind region the price has been calculated to.
That last one is the one to check when you’re comparing suppliers. A quote priced to the wrong region isn’t cheaper, it’s just wrong, and it won’t get through council.
If you want to see the range first, the shed types page has everything, and there are set sizes ready to go on the shed kit specials page. More common questions are answered on our FAQs.
Or just ring us on 1300 887 433 and describe what you want in your own words. Working out the technical version is our job.