What the surface is actually telling you
A settled patio or a rippled driveway looks like a paver problem. In most cases it is not. Concrete pavers are dense, well-fired units that routinely outlast the granular base beneath them by twenty or thirty years. When a section sinks, tilts or develops a ridge, the stone has moved with the base rather than failed on its own. That distinction matters because it changes the repair entirely.
The first thing to sort out is whether the pavers themselves are damaged or whether they have simply shifted. Run your eye across the surface at a low angle on a bright morning. Settlement shows as a smooth bowl or a gradual slope. Frost heave shows as a ridge or a lifted corner. Structural damage to the paver, spalling, a through-crack, a shattered face, is a different category and needs a different answer.
Toronto's freeze-thaw cycle is hard on bases. A surface that was installed without adequate compaction, without a proper granular sub-base depth, or without edge restraint along the perimeter will move. The pavers follow. Understanding why interlock sinks in this climate is the starting point for any honest repair conversation.
When re-levelling is the right call
Lift and relay is the correct scope of work when the pavers are structurally sound and the base problem is correctable. That covers the majority of settled surfaces we open in Toronto.
- The pavers lift cleanly without breaking. A paver that comes up in one piece and has a flat, unspalled face is reusable.
- The settlement is localized, covering a section rather than the whole surface. A bowl near a downspout or a low corner near the lawn edge is a classic washout pattern.
- The base has lost its fines through water infiltration but the granular material is otherwise intact. Adding and recompacting bedding sand, then relaying the pavers, restores the surface.
- Edge restraint has failed along one run, allowing the border course to migrate outward and the field pavers to follow. Resetting the edging and relaying the affected zone is straightforward.
- The pattern and colour are consistent across the surface. If you relay into a matched field, the result is indistinguishable from new work once joint sand is swept in.
A re-levelling job on a typical Toronto patio runs less than a full replacement by a meaningful margin because the material cost is near zero. The labour is the same category of work, but you are not sourcing and delivering new stone. For a detailed look at what moves the number, the re-levelling cost page breaks down the variables.
One thing worth checking before any quote is finalized: if the base repair requires excavation deeper than a few centimetres, Ontario One Call must be contacted before any digging begins. That is a legal requirement in this province, not a formality.
When replacement is the honest answer
There are surfaces where re-levelling would be doing the work twice. A contractor who tells you to relay pavers over a base that cannot hold them is not saving you money.
- The pavers are spalling or cracking across a wide area. Spalling, where the face of the paver flakes away, usually traces back to a sealer applied over damp stone or to a low-quality unit that has absorbed water and cycled through too many freezes. If more than a quarter of the surface shows this, replacement is more cost-effective than selective patching.
- The base has failed completely. Soft spots underfoot, pavers that rock under foot traffic, or a surface that has settled more than once in five years all point to a base that needs to come out and be rebuilt from the sub-grade up. Relaying into a failed base produces the same result in two or three seasons.
- The pavers are discontinued and matching is impossible. A partial relay in a noticeably different colour or texture looks worse than a full replacement. The discontinued pavers page covers the options when the original product is no longer available.
- The drainage grade is wrong across the whole surface. If water pools at the house foundation or across the centre of a patio, the fall was never correct. Fixing grade means lifting everything, regrading the sub-base, and relaying. At that point the scope is effectively a new installation.
- The border or soldier course has been driven over repeatedly and is shattered. A border course replacement can sometimes be done in isolation, but if the damage extends into the field, full replacement is cleaner.
How to read base condition before deciding
You do not need to lift the whole surface to understand what is under it. A few indicators are visible before the first paver comes up.
Joint sand migration is one of the clearest signals. If the joints are empty along a run and the sand has washed into a low corner or into the lawn, water has been moving through the base. That is a joint washout pattern, and it tells you the bedding layer has been disturbed. Whether the base granular beneath it is still sound determines the scope.
Lippage, where adjacent pavers sit at noticeably different heights, is another indicator. A single lifted paver near a tree root is a spot repair. Lippage across a two-metre run suggests the bedding sand was not screeded evenly or has compressed unevenly under load. That is a re-levelling job.
Soft spots underfoot are the most direct signal of base failure. Press firmly on a paver that feels spongy. If it flexes or the adjacent pavers move, the granular base has either washed out or was never compacted properly. Opening that section will confirm it, but the repair will involve base work regardless.
At Toronto Interlock Repair, the standard practice before quoting any re-levelling job is to pull a paver or two in the worst area and look at the bedding sand depth, the granular layer, and the sub-grade. That five-minute check changes the scope of work more often than any surface reading does. See the full process on the base repair page.
Partial relay versus full surface scope
Not every job is all-or-nothing. A sunken section near a downspout on an otherwise stable patio is a candidate for a partial relay. The affected zone comes up, the base is corrected, and the pavers go back down. If the surrounding field is level and the pavers match, the result is clean.
The risk with partial work is colour variation over time. Pavers weather and accumulate surface deposits differently depending on sun exposure, foot traffic, and whether they have been sealed. A paver that has been outside for ten years will not look identical to the same unit freshly relaid, even if it is the same product. On a driveway where the contrast is obvious, some owners prefer to relay the whole surface for visual consistency.
Driveways present a specific challenge because the load is higher and the consequences of base failure are more visible. A sunken driveway that has developed ruts under wheel tracks usually needs base work across the full travel path, not just the worst spot. Patching the low point without addressing the compaction under the adjacent runs produces a surface that develops new low points within a season or two.
For patios, the threshold is different. A sunken patio section near the house is worth addressing promptly if water is running toward the foundation, but a settled corner away from any structure is rarely urgent. A small settled area under about a square metre is often not worth a call-out on its own unless it is a trip hazard or draining toward the house.
Fixing drainage so the repair holds
The most common reason a re-levelling job fails within a few years is that the water problem that caused the original settlement was not addressed. Pavers are not waterproof. Water moves through the joints, through the bedding sand, and into the base. In a well-designed surface, it exits at the edges or through a drainage layer. When it has nowhere to go, it saturates the fines, they migrate, and the surface settles again.
Before closing any repair, the grade needs to be confirmed. A minimum fall away from structures is the standard, and on a surface that has settled it is worth checking that the corrected grade actually achieves that. A string line across the surface tells you quickly whether the relay has restored the intended slope.
Edge restraint is the other piece that gets skipped. Spike edging along the perimeter holds the border course in place and keeps the field pavers from migrating outward under load. A surface without it will spread at the edges over time, opening joints and allowing more water infiltration. The edge restraint page covers the options.
Where surface water is arriving from a neighbouring property or from a roof without adequate downspout extension, a channel drain at the low point of the surface can intercept it before it reaches the base. That is an addition to the repair scope, not a replacement for it, but it is often the difference between a repair that holds and one that needs revisiting.
Once the base is corrected and the pavers are relaid, the joints need to be filled. Polymeric sand is the standard choice for a surface that has had water problems, because it sets firm and resists washout better than plain joint sand. It is not a permanent fix for a drainage problem, but it reduces the rate at which fines migrate through the joints.
Making the call before you phone
The decision tree is simpler than it looks from the outside. Pavers that are intact and a base that is correctable point to re-levelling. Pavers that are damaged across a wide area, or a base that has failed completely, point to replacement. The grey area is a base that has failed but pavers that are still good, and in that case the honest answer is a full base rebuild with the existing pavers relaid on top, which is closer to replacement in cost but avoids the material expense of new stone.
- Walk the surface and note where it is soft, where it rocks, and where the joints are empty.
- Look at the pavers themselves for spalling, through-cracks, or shattered faces.
- Check the grade with a straight edge or string line to see whether water is running toward or away from the house.
- Look at the perimeter for missing or failed edge restraint.
- Pull one paver in the worst area if you can do so without breaking it, and look at the bedding sand depth and the granular layer beneath.
That five-step check gives any contractor enough information to quote accurately. If a contractor quotes a full replacement without looking at the base, or quotes a re-levelling job without pulling a paver, the scope may not match the actual problem.
For a sense of what either path costs in the Toronto market, the paver replacement cost page and the re-levelling cost page both lay out the variables that move the number. No two jobs are identical, and a surface that looks simple from the top sometimes reveals a more involved base condition once it is opened.
Toronto Interlock Repair offers assessments where the base condition is checked before a scope is agreed on. That is the only way to give a quote that holds.