Can a Vancouver paver patio sit over an existing concrete slab?

Yes, you can install pavers over an existing concrete slab in Metro Vancouver — but only if the slab is structurally sound, properly sloped, and the finished height won't create problems with doors, thresholds, or drainage.

This approach is sometimes called a "paver overlay" or "thin-set installation," and it's a legitimate method that saves the cost of demolishing and removing the old concrete. That said, it's not always the right call, and Metro Vancouver's wet climate adds some important considerations that make this decision more nuanced than it might seem in a drier region.

When Installing Over a Slab Makes Sense

The existing concrete must pass a few tests before an overlay is worth considering. First, it needs to be structurally intact — no major cracking, heaving, or soft spots. Hairline cracks are generally acceptable, but large cracks (wider than 6mm), sections that flex underfoot, or areas where the slab has settled unevenly are red flags. Pavers laid over a failing slab will mirror every problem beneath them, often within a season or two.

Second, the slab must drain properly. This is where Metro Vancouver's rainfall becomes critical. If the existing concrete already ponds water or drains toward your house, adding pavers on top won't fix that — it will hide the problem while the water continues to saturate the area beneath. The finished paver surface needs a minimum 2% slope (about 6mm per 30cm, or ¼ inch per foot) away from the building. If the slab doesn't already have that slope, a paver overlay will likely make drainage worse, not better.

Third, check your door and threshold heights. Adding pavers over an existing slab raises the finished surface by at least 40-50mm (the thickness of a standard 60mm paver sitting on a thin bedding layer, or a 40mm paver on a mortar bed). If your patio door threshold, sliding door track, or step height is already close to the existing slab level, this added height can create a trip hazard, block door operation, or direct water toward the building's foundation.

Two Methods for Paver Overlays

Dry-laid on a thin sand bed — A thin layer of coarse bedding sand (25mm or so) is screeded over the concrete, and pavers are laid on top. This is faster and cheaper than mortar, but it relies entirely on the concrete slab for drainage and structural support. The sand layer must be kept thin and consistent, and edge restraints must be anchored into the concrete perimeter. This method works well when the slab is in good shape and properly sloped.

Mortar-set (wet-laid) — Pavers are set individually in a mortar bed over the concrete, similar to tile installation. This method is more labour-intensive and expensive, but it allows the installer to fine-tune the slope of each paver and create a more rigid, stable surface. It's often used for natural stone overlays (flagstone, slate, granite) where the irregular thickness of the stone requires a mortar bed to achieve a level surface. The tradeoff is that mortar-set pavers are harder to repair — you can't simply lift and relay an individual paver the way you can with a dry-laid installation.

The Case for Demolishing the Old Slab

Sometimes the right answer is to remove the existing concrete entirely. If the slab is cracked, settled, or draining toward the house, an overlay just delays the inevitable. Demo and removal of a 400 sq ft concrete slab in Metro Vancouver typically runs $2,000-$4,500 including disposal, which is real money — but it gives you a clean slate to build a proper granular base with full drainage control. A well-built paver installation on a proper base will outlast any overlay by many years.

In Metro Vancouver's clay-heavy soils (common in Surrey, Burnaby, Delta, and Langley), the original concrete slab may have been poured on an inadequate base that has since settled. If the slab is uneven, the overlay will be uneven too.

Practical Tips

Before committing to an overlay, have a contractor assess the existing slab with a level and a hose — run water across it and watch where it goes. Check your door threshold clearance with a tape measure. And confirm with your municipality whether the added height creates any issues with grading or drainage bylaws.

If you're ready to explore options, Vancouver Interlock can match you with an experienced local hardscape contractor who can assess your slab and give you an honest recommendation — free of charge.