What changes when the base already exists
On soil, roughly 30% of the job is excavating and building a base. On a sound slab, that work is already done, which is why people assume this is the cheap version. What replaces it:
- No pins, adhesive instead. There is nothing to peg into. The turf is bonded down with a turf adhesive, which means surface preparation matters: the slab has to be clean, dry and sound for the adhesive to hold.
- A foam underlay, typically around 5mm. It softens a surface that has no give at all and it evens out minor imperfections in the concrete. It is a comfort and levelling layer, not a drainage layer.
- Drainage becomes a design item rather than an assumption. On soil, a permeable turf backing over a compacted crushed rock base lets water keep moving downward. On concrete, the backing delivers water to a surface that may not shed it at all.
- Edges are finished, not restrained. Perimeters are glued and trimmed against walls, thresholds and paving edges rather than held by an edge restraint, and neat trimming around downpipes, gully traps and steps is a real part of the labour.
Drainage: the whole job, honestly
Concrete laid as a paving surface usually has some fall to it, because whoever poured it wanted rain off it. Concrete laid as a shed pad, a clothesline slab or an infilled area often does not. The first thing worth doing, before anyone quotes, is a bucket of water on a still morning. Watch where it goes. If it sits, you do not have a turf problem, you have a slab problem, and turf will conceal it rather than solve it.
Where there is no usable fall, the realistic options are to build one with a screed or a build-up, to cut a channel or spoon drain to an existing outlet, or in some situations to drill drainage holes through the slab. Which one applies depends on the slab's thickness, what is beneath it, and whether it forms part of a building. That last consideration is exactly why this is a conversation with an installer and sometimes a builder rather than something to decide from a web page. What we will say is that a quote which does not mention drainage at all on a hard-surface job has not engaged with the main risk.
There is a Perth wrinkle worth knowing. Much of the metro area sits on free-draining Bassendean and Spearwood sand, so wherever water leaves the slab it usually disappears quickly once it reaches ground. That is a genuine local advantage over cities on heavy clay. It is not universal, though: parts of the plain are mapped by the WA Government as poorly drained sand with clay or an iron-organic hardpan below, and the plain margin suburbs sit on sand over clay. Getting water off the slab is step one either way; where you send it is step two.
Over paving, and over a courtyard that belongs to a strata company
Paving behaves like a slab if it is level, stable and well laid. It does not if the pavers rock, have settled unevenly or sit on a failing sand bed, because every high point reads through the pile and every low point becomes a wet spot. Judge the paving as it is today rather than as it will look with grass on it.
The other question in Perth's villa stock is whose courtyard it is. In a survey-strata scheme the lot is surveyed land, so a courtyard inside your boundary is normally yours. In a strata scheme the lot is cubic space defined by reference to the building, and clause 3AB of Schedule 2A fixes the lot boundary for many modern single-tier schemes at "the external surfaces of the building occupying the area represented on that floor plan", expressly not reaching anything outside a building. The practical result is that a great many Perth villa courtyards are common property over which the owner has exclusive use rather than land the owner owns. Only your scheme plan settles it, and Landgate points people to a licensed land surveyor or its Strata Enquiry Line for the answer.
On approvals, the WA position is more determinate than most people expect. The hard threshold, the lot-alteration regime in sections 87 and 88 of the Strata Titles Act 1985, applies to a structural alteration, and turf is very unlikely to meet the regulations' test for a structure. What usually does apply is the default conduct by-law, Schedule 2 by-law 14 on the appearance of a lot, which requires the strata company's written consent for something visible from outside that is not in keeping with the rest of the building. Two limits on that: no WA statute, regulation, default by-law or Landgate guidance mentions artificial turf at all, so the position is derived, and we have not been able to search WA tribunal decisions to see if it has ever been tested. Get consent in writing before material is ordered.
Heat, in the hardest case there is
A small enclosed courtyard, walls on three sides, concrete underneath, facing west, in a city that averages 28.7 days a year at or above 35°C and 4.5 at or above 40°C at Perth Airport. That is the worst-case heat scenario for synthetic turf and it is also an extremely common Perth courtyard. We would rather say so than let you discover it in February.
What actually helps: shade over part of the space, whether that is a tree, a sail or a pergola; a lighter yarn colour, which runs cooler as a matter of physics rather than marketing; hosing the surface before use, which drops the temperature quickly; and using the space early or late. Suppliers sell products with specific cooling claims attached, for instance All Seasons markets a COOLplus yarn it says runs 30% cooler and an evaporative Cool-Off infill; those are the supplier's claims and we report them as claims. Manufacturer TigerTurf, for its part, acknowledges the surface gets warm while noting it stays below the extremes of asphalt and concrete, and recommends the same mitigations.
For what any of this costs, and how the small-job effect lifts the per-square-metre rate, see the Perth cost guide. If the surface is a dog area rather than a sitting area, the pet turf page covers backing permeability and the cleaning routine, both of which matter more on a hard base.
Turf over hard surfaces: common questions
Can turf go straight onto an existing slab?
Yes, and it is one of the more common small jobs in Perth's villa and townhouse stock. There is no excavation and no crushed rock base, because the slab already is the base. The turf is bonded with adhesive rather than pinned, and a foam underlay of around 5mm is usually laid first to soften the surface and even out minor imperfections. The whole question then becomes water: where it goes, and whether it can get there.
What if the slab has no fall?
Then you have a decision to make before anything is glued down. A flat slab holds water under the turf, and a permeable turf backing simply delivers water to a surface that will not shed it. Options include creating a fall with a screed or a build-up, cutting a drainage channel or spoon drain to an existing outlet, or drilling drainage holes through the slab where that is appropriate and permitted for the structure. Which is right depends on the slab, what is under it and whether it is part of a building. That is an installer and, sometimes, a builder question, not a turf question.
Does old paving need to come up first?
Not necessarily. Well-laid, level, stable paving can act as the base in much the same way a slab does. Loose, rocking or badly settled pavers are a different matter, because every high point telegraphs through the pile and every low point collects water. The honest test is whether the surface is level, sound and draining now. If it is not, laying turf over it hides the symptom and keeps the cause.
Is a foam underlay necessary?
It is standard practice on a hard base and it does two jobs: it takes the harshness out of a surface with nothing underneath it, and it smooths out minor imperfections in the concrete. Around 5mm is the figure Australian installation guidance uses. Note that an underlay is a comfort and levelling layer, not a drainage solution. If water has nowhere to go, foam will not save it.
Does turf on concrete get hotter than turf on soil?
A concrete slab in full sun is already a heat store, and that is the honest concern in a city that averages 79 days a year at or above 30°C at Perth Airport. Unshaded artificial turf has been reported by Western Sydney University researcher Dr Sebastian Pfautsch at close to 100°C. Manufacturers including TigerTurf note the surface gets warm and point to hosing, shade, cooling infill and timing. Lighter yarn colours run cooler. A small, enclosed, west-facing courtyard over concrete is the hardest heat case there is, and it is worth designing shade into it rather than hoping.
Can I do this on a strata or survey-strata courtyard?
That depends first on whether the courtyard is part of your lot. In a survey-strata scheme it usually is, because the lot is surveyed land. In a strata scheme the lot is cubic space defined by reference to the building, and an outdoor paved area is often common property. Where the area is visible from outside, the default WA conduct by-law on the appearance of a lot requires the strata company's written consent. Laying turf is very unlikely to be a structural alteration under sections 87 and 88 of the Strata Titles Act 1985, which is the harder threshold. No WA statute or guidance mentions artificial turf by name, so this is derived rather than stated.
Is a slab job cheaper than a lawn job?
Per square metre, usually not. You save the excavation, the base material and the spoil removal, which is real money, but you add adhesive, underlay and often drainage work, and slab jobs tend to be small, so the fixed costs of getting a crew and materials to site are spread thinly. One Australian supplier publishes balcony and rooftop work at $90 to $150 per square metre installed, above its standard residential band, largely because of membrane and drainage requirements. Ask for the drainage solution to be itemised rather than assumed.
Do Perth's watering rules matter for a paved courtyard?
Only in the sense that they stop applying. The two-day sprinkler roster and the 1 June to 31 August Sprinkler Switch-off govern watering lawns and gardens with sprinklers, and neither addresses artificial turf. Worth noting separately that Water Corporation and DWER material does not treat hosing hard surfaces the way some eastern-state utilities do, so we are not going to import a rule that WA has not published.
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