In much of Britain a patio is used on a handful of summer evenings, then left to the moss. On the Sunshine Coast, the outdoor area is often the busiest room in the house for most of the year. This article covers what goes into building one well: the slab, the finish, the roof over it and the ground underneath, which near the beach is rarely what a British homeowner expects.
The alfresco is a room, so plan it like one
Australians use the word alfresco for a covered outdoor living space, usually attached to the house and opening from the kitchen or family room. On the Sunshine Coast it typically holds a dining table, a barbecue and somewhere to sit out of the sun, and for many households it is where meals happen from September to May.
That changes the priorities. Size matters more than in a British garden: a table for six with chairs pulled out, plus space to walk around it and a barbecue that is safely clear of the eaves, takes up more room than most people guess. Shade matters more than sun. And the link to the indoors matters, because a step down, a lip or a door track in the way becomes a daily irritation.
Many newer homes are designed with the alfresco floor at, or very close to, the internal floor level. That looks good and is easier to live with, but it means drainage at the threshold has to be thought through carefully so that a summer storm does not drive water under the sliding doors.
Falls, drainage and the summer storm
South-east Queensland gets heavy summer rain, often arriving as short, intense afternoon storms. Any slab beside the house needs a fall, a gentle slope, that carries water away from the building rather than towards it. The fall is subtle enough that you will barely notice it on a dining table, but it has to be built in from the start; it cannot be added later.
Where the slab meets the house, check that it sits below any weep holes in the brickwork and does not bridge the termite protection or the damp-proof arrangement at the base of the wall. A slab poured too high against a wall is a common way for water and termites to find a path into a home. Grated drains at the threshold and a lawful connection to stormwater finish the job.
Sand, salt and what lies beneath
Close to the beach, from Caloundra up through Mooloolaba and Coolum to Peregian, many blocks sit on sand. Sandy ground does not swell and shrink like the reactive clays found further inland and in the hinterland, which is helpful, but it needs proper compaction before concrete goes on it. Loose sand under a slab will settle unevenly and cause cracking.
Some low-lying parts of the coast also contain acid sulfate soils, which can release acid when they are dug up and exposed to air. If your project involves significant excavation, such as for a pool, the council may require these soils to be identified and managed. The Sunshine Coast Council’s mapping and your builder or certifier can tell you whether that applies to your block.
Salt air is a factor for anything metal. Reinforcing steel needs adequate concrete cover, and exposed fixings, brackets and roof framing near the water should be rated for a coastal environment. Galvanised or stainless options cost more upfront and save money later.
Finishes for bare feet and wet pool decks
An outdoor area on the coast is walked on barefoot, often with wet feet coming straight from the pool. Two things follow. The surface needs to grip when wet, and it should not get scorchingly hot in direct sun. Dark-coloured concrete and some pavers can become unpleasant to stand on in January.
Popular choices include exposed aggregate, which has natural texture; honed concrete with an anti-slip treatment; and broom or textured finishes for purely practical areas. Pool surrounds have additional rules: the area around a pool forms part of the barrier arrangements, so check fencing clearances and gate positions before the slab layout is fixed.
Because the right choice depends on the soil, the exposure and how the space will be used, it helps to look at local work and to speak with experienced concreters on the Sunshine Coast who pour on sand and near salt water routinely. Ask to see jobs that are a few years old, not only freshly sealed ones.
Roofs, footings and approvals
A patio roof over the alfresco is almost standard. It might be insulated sandwich panels, a skillion attached to the existing roofline or a freestanding gable. Whatever the style, the posts need proper footings, and those footings are designed for both the soil and wind uplift. In a storm, a roof wants to lift, and the footings and fixings hold it down.
In Queensland, many patio roofs need building approval through a private building certifier, and some also need council approval because of boundary setbacks or overlays. Work above a modest value must be carried out by a contractor licensed with the Queensland Building and Construction Commission, so check the licence before paying a deposit.
It is usually simpler to design the slab and roof together. Footings can be placed in the right spots before the concrete goes down, and the fall of the slab can be coordinated with where the roof drains discharge.
Questions readers ask
Do I need approval just for a concrete slab?
A plain slab at ground level often does not, but drainage, overlays or proximity to boundaries can change that. A roof over it is far more likely to need approval, so check with a certifier or the council.
Should I seal an outdoor slab?
Sealing helps resist staining from barbecue fat and leaf tannins. Choose a sealer with an anti-slip additive for any area that gets wet.
Are pavers better than concrete on sand?
Pavers laid on a well-compacted base cope well with small movements and are easy to lift for repairs. Concrete gives a seamless surface and is often cheaper over large areas.