Accurate measurements are the fastest way to get the right DIY kit first time — and avoid annoying surprises on install day. Online Patios recommends using their free “How to Measure” guide before requesting a quote, so your kit can be matched to your space and requirements.
Tools You Will Need
A high-quality tape measure and a level are essential. Once you have your numbers, head over to our Carport Specials to see which standard size fits your space best.
✅ Tape measure (5–8m is ideal), pencil, notepad
✅ A second person (seriously—makes it easier and more accurate)
✅ Step ladder (only if needed and safe)
✅ Your slab/deck dimensions (if the base is already down)
Pro tip: measure everything twice and write it down as you go.
Measuring Height and Clearance
Clearance is vital for caravans and 4WDs. If you’re unsure, check our Flyover Kits which offer adjustable height options.
The two core measurements Online Patios uses
Across their kits, the sizing is generally based on two measurements:
- Length (the long side — often along the house wall)
- Roof sheet length / span (how far the roof projects out)
Our guide also notes roof sheet sizing considerations:
- Insulated roof sheets are 1m wide
- Single skin sheets are 331mm wide
Measure by kit type (choose the one that matches your build)
1) Flyover roof (patio/carport)
A flyover sits higher and uses brackets to span over the existing roofline.
Measure:
- Length along the house wall (this is measurement #1).
- From the wall out to where you want the roof to finish (slab edge/deck edge).
- Add 300mm from the back wall so extenda brackets sit correctly over the house frame.
- Add another 200mm at the front for guttering and fascia flashing.
So if you measure 4.5m from wall to slab edge, the guide example adds 500mm total (300mm + 200mm) to reach 5.0m sheet length.
2) Attached to a wall (timber/brick/block/concrete)
This is a direct wall-attach style.
Measure:
- Length along the house wall (measurement #1).
- From the wall out to the roof finish point.
- Add 200mm at the front for guttering and flashing (e.g., 4.5m becomes 4.7m).
3) Attached to fascia (timber or metal fascia)
This is one of the most common DIY styles—and also the one where people forget a key subtraction.
Measure:
- Length along the house wall (measurement #1).
- Wall to roof finish point, then add 200mm for guttering/flashing.
- Measure wall to edge of fascia/eave, then deduct that eave measurement from your sheet length.
Example from the guide: if your wall-to-finish is 4.7m and your eave is 600mm, your sheet span becomes 4.1m.
4) Freestanding patio/carport
Freestanding means no attachment to the home—supported entirely by posts.
Measure:
- Measure the longest side along the slab/deck/area (measurement #1).
- Measure the other direction out to the finish point, then add 300mm to allow for guttering and flashing.
Example: 3.0m becomes 3.3m.
Two important extras people forget
Cutback (insulated roofing only)
When ordering insulated sheets, Online Patios asks for a cutback (LHCB or RHCB). It’s used to determine which side you’ll start laying the insulated roof sheets from, based on the fall direction and your installation start side.
Posts: slab plates vs footings vs deck
Online Patios often lists options depending on whether posts are fixed to a slab or set into footings, and notes that if you need posts attached to a deck, you should let them know so the kit components can be adjusted.
Quick accuracy checklist (takes 2 minutes, saves headaches)
- Confirm the slab/deck is square (check diagonals corner-to-corner)
- Note any obstructions: doors, windows, downpipes, gas meters, hot water units
- Think about where you want guttering to drain
- Take a few photos from wide angles—super helpful for quoting
Want the easy option? Download the free guide (and we’ll help if you’re unsure)
Online Patios provides a free “How to Measure” PDF you can view/download, and they actively recommend using it before requesting a quote.
And if anything feels unclear—attachment type, fascia depth, cutback, slab vs footings—just reach out. Their kits are supplied as engineered DIY packages with plans and instructions, and they can also customise to suit exact sizing and wind rating needs.
Get in touch
Call 1300 156 381 and we’ll help you confirm your measurements and get a fast, accurate quote.
Still nervous about your measurements? Don't be. Request a Fast Quote and our team will review your dimensions to ensure a perfect fit before we start production.
- Double-Checked: We review all measurements before your kit goes to the factory.
- Expert Guidance: Stuck on a tricky corner? Send us a photo and we’ll guide you.
- Standard Sizes: We offer kits in the most common Australian home dimensions to simplify your choice.
Got Your Measurements Ready?
Take the next step toward your new outdoor space. Whether you need a standard size or a custom fit, we make the process stress-free.