I laid pavers for eleven years before I picked up an inspection licence, so when I crouch down at a front entry and rock a paver with my palm, I’m not guessing what I’m feeling for. On a job in Perth’s outer eastern suburbs last month, six pavers near the letterbox rocked under light pressure, and when I lifted one the bedding sand underneath had washed into a hollow the size of a dinner plate. The owners had no idea — from standing height it just looked like a slightly uneven path.
Most of the Perth metro sits on free-draining sandy soil, which is good news for a slab footing but bad news for paving bedding layers. Water that would pool and soften clay somewhere else just disappears straight through Perth sand, taking the fine bedding material with it. That’s what erosion under paving looks like here — not a wet, boggy patch, but a slow disappearing act underneath a surface that still looks dry. Add stormwater from a downpipe discharging onto the same corner, or an irrigation line running under the path, and the hollowing speeds up considerably.
The rule of thumb most inspectors and building surveyors work to is a lip of 5mm or more between adjacent pavers being worth flagging, and anything past 10mm going in as a genuine trip hazard rather than a cosmetic note. I measure with a straightedge and a tape rather than eyeballing it, because settlement is deceptive under raking light — a shadow can make a 3mm lip look far worse than it is, and flat midday sun can hide a real one. Location matters too: the same lip on a side path gets a lower priority than one on the main entry path where an agent will be walking buyers through at inspection time.
A lot of Perth’s newer subdivisions are built on cut-and-fill blocks, where the rear of the block has been built up with imported fill to level a sloping site. Paving laid across the boundary between original sand and that fill will often settle unevenly for the first few years as the fill compacts under its own weight and under foot traffic. It’s not a construction fault in most cases — it’s what happens when you build in the first two or three years after fill goes down — but it does mean paving on a five-year-old fill block deserves a closer look than the same paving on an older, established block. I always ask when the block was filled and by how much, because a metre of imported fill under a rear patio behaves very differently in year two than it does in year eight, and the paving on top is the first thing to show it.
Re-bedding a section of settled paving runs somewhere around $40 to $70 per square metre in the Perth market, while a full relay of a driveway-sized area, including new bedding sand and edge restraints, tends to land between $3,500 and $7,000. Termites are worth mentioning here too — paving laid hard up against a timber-framed wall with no visible weep holes or inspection gap is exactly the kind of thing that hides termite activity from a routine visual check. If the settlement is isolated to a small area I’ll usually suggest getting Perth Pavers out to quote the re-bed properly rather than guessing at a number for the contract, since bedding sand composition and paver type both change the price more than people expect.
How much paver movement is considered normal settlement? A few millimetres in the first one to two years after laying is common, especially on fill. Ongoing movement past that point, or sudden new lips appearing on established paving, is what gets flagged as active.
Does paving settlement affect a building and pest inspection outcome? Paving itself sits outside the structural scope of most reports, but where it touches a wall or hides subfloor vents, it gets noted because of what it might be concealing.
Can I just top up with more sand instead of re-bedding? It’s a short-term fix at best. Without addressing the erosion source — usually a downpipe outlet, a condensate line, or an irrigation head discharging under the surface — the new sand washes out on the same timeline as the original, and you end up doing the job twice within a couple of wet seasons.