A flat roof patio is the most common design we install across the Perth metro area, and the one most people picture when they imagine adding cover to a backyard. It sits on a single low plane, keeps the profile down where height is restricted, and gives the most usable covered area for the money.
It is also the design most often built badly, because the things that make a flat roof work are the things you cannot see from the driveway.
The short version
Most Perth volume builders do not include a patio as a standard inclusion, so it becomes an owner-arranged addition after settlement. Newer estates are also where planning approval and design guidelines are most likely to apply, which is worth checking before you sign.
A Flat Roof Patio Is Not Actually Flat
This is the part worth understanding before you compare quotes. Every flat roof patio is built with deliberate fall so water moves off it. If it were genuinely level, water would sit on the sheeting, find the laps, and eventually find its way inside.
The amount of fall is calculated from the span, the height available at the house connection, and where the water needs to go. On a wide patio with limited height to work with, that calculation is most of the engineering. It is also why we measure on site rather than quoting from a description.
The Gutter Does More Work Here Than on a Pitched Roof
We use a box gutter by default. Every house is different though, and the guttering a job actually needs is normally determined by what we are attaching to, so it is one of the things we assess at the on-site quote rather than assume in advance.
On a flat roof the gutter carries more importance than on a pitched one, because water arrives with less momentum behind it. Getting the sizing right is what stops a Perth downpour backing up into the eaves.
Roof Materials for a Flat Roof Patio
Flatdek, Trimdek and corrugated are all Colorbond profiles and all work on a flat roof. Flatdek gives the flattest, most contemporary line and is the profile we fit most often. Colorbond is durable, pre-painted, available across the full colour range, and all the coil comes from BlueScope.
Solarspan is the insulated option. On a flat roof facing west it makes the single biggest difference to comfort through summer, because a low flat plane collects heat all afternoon and radiates it straight down. The underside also finishes as a clean ceiling rather than exposed sheeting. Our roof materials guide compares the options.
Flat, Skillion or Gable
All three are built on the same powdercoated, epoxy-primed, 100% Australian Orrcon steel system, so the choice is about proportion, height and light rather than quality.
- A flat roof is the most cost effective and keeps the profile low. It suits a modern home with a low roof line and a space that already gets enough light.
- A skillion runs a single slope, which gains height on one side and sheds water decisively without carrying a full pitch across the span.
- A gable gives the most height through the middle and the most open feel underneath, and it suits a house that already has a pitched roof line.
If a flat roof would leave the area too dark or too low, that is the signal to look at a gable. If cost, a low profile and maximum covered area matter more, flat is the better use of the budget.
Approvals and Build Time
A flat roof patio is a permanent structure, so it needs building approval in most cases. We prepare the site plan and elevations, prepare the engineered specifications and lodge on behalf of the owner. Certified through a private building certifier, approval takes approximately 2 weeks. Installation follows 8 to 12 weeks after that, because the structure is manufactured to your measurements.
Book a Free On-Site Quote
Call 08 6500 0614, email sales@onestoppatioshop.com.au or request a quote online. As a registered builder we provide a 6-year structural warranty on every job.
Frequently Asked Questions
A patio with a roof on a single low plane rather than a pitch. It is the simplest and most cost effective design, keeps the profile down where height is restricted, and suits modern homes with low roof lines. It is always built with enough fall to drain properly.
Not when they are built with the correct fall and the right gutter. A flat roof patio is never truly level. The fall is calculated from the span, the height available at the house connection and where the water needs to go, which is one of the reasons we measure on site.
It is worked out per job rather than fixed in advance, because it depends on the span and the height available where the structure meets the house. On a wide patio with a low fascia, that calculation is most of the engineering.
Generally yes, because it uses less material and a simpler roof structure. Both are quoted per job, since span, roof material and how the structure connects to the house move the price more than the shape alone.
Yes. Solarspan is the insulated option, built on a Bondor panel with a Colorbond top-skin. On a west facing flat roof it makes the biggest single difference to comfort through summer, and it finishes as a clean ceiling underneath.
We use a box gutter by default. Every house is different though, and the guttering a job actually needs is determined by what we are attaching to, which is assessed at the on-site quote.
