Service
Concrete Crack and Spall Repairs
Cracks in concrete are common, and many are harmless. Concrete shrinks as it dries and moves slightly with temperature and ground conditions, so fine cracks often appear even in well-built slabs. Other cracks are warning signs: of ground movement, failed bases, tree roots or water getting underneath. Spalling, where the surface flakes or breaks away, can be cosmetic or can point to deeper issues. Rowville Concrete assesses and repairs cracked, spalled and lifted concrete on driveways, paths, patios and slabs across Rowville and nearby suburbs, and replaces damaged sections when repair isn't enough.
Understanding the cracks you're seeing
Fine shrinkage cracks
Hairline cracks, sometimes in a random or map-like pattern, often form as concrete dries. They're usually cosmetic and may not need more than monitoring, sealing or a surface treatment.
Cracks at or near joints
Control joints are designed to encourage cracking in straight lines. Cracks that follow joints are usually doing what's intended. Cracks that run beside a joint or across a panel may mean the joints were too far apart or cut too late.
Wider or displaced cracks
When one side of a crack is higher than the other, or the crack is wide enough to catch a heel or grow weeds, the slab is likely moving. Causes include poor compaction, washouts from leaking pipes or downpipes, tree roots and changes in soil moisture. These cracks usually need more than a surface fill.
Structural cracks in house slabs or walls
Cracks in house slabs, footings or walls should be looked at by a structural engineer, especially if they're growing, if doors and windows have started sticking, or if floors feel uneven. Soil movement varies widely from site to site, and a proper assessment is the starting point.
Spalling and surface damage
Spalling shows up as flaking, pitting or pieces breaking away from the surface. Common causes include:
- •surface weakness from finishing or curing problems when the concrete was poured;
- •rusting reinforcement close to the surface expanding and cracking the concrete above;
- •impact damage from heavy loads or dropped objects;
- •wear from water, chemicals or abrasion over time.
Shallow surface spalling can often be patched or resurfaced. Where rusting steel is involved, the damaged concrete needs to be cut back, the steel treated or replaced, and the area rebuilt.
Repair options
Crack filling and sealing
Cracks are cleaned out, often widened slightly with a grinder to give the filler something to grip, and filled with a flexible sealant or a rigid repair compound depending on whether the crack is still moving. Fillers stop water and weeds getting in, but they won't hide the crack completely.
Patching
Spalled or chipped areas can be patched with repair mortars. Patches rarely match surrounding concrete perfectly in colour, but they restore a sound surface.
Resurfacing
Where a slab is sound but covered in fine cracks and patches, an overlay can refresh the whole surface. See concrete resurfacing.
Saw-cutting and section replacement
For slabs that have sunk, lifted or broken into pieces, the most reliable fix is to saw-cut around the damaged section, remove it, repair the base and pour a new section. This is common for driveway panels near garages, crossovers and trees, and for path bays over old service trenches. Dowels can connect the new concrete to the old where the design calls for it.
Full replacement
When damage is widespread, replacing the whole driveway or path may be better value than repeated repairs. See driveway replacement.
Finding the cause
Repairs last longer when the cause is dealt with. We look for:
- •Water. Broken downpipes, leaking taps or poor falls saturating the ground under the slab.
- •Trees. Roots lifting or drying the soil near the concrete.
- •Loads. Heavy vehicles, trailers or skip bins on concrete not designed for them.
- •Base failures. Soft or poorly compacted material under the slab.
Trip hazards on footpaths
If a cracked or lifted section is on the council footpath outside your property, it's council land, and repairs follow council requirements. See council footpath reinstatement.
Where we quote
We quote crack and spall repairs across Rowville, Noble Park North, Wantirna, Boronia, Glen Waverley, Lysterfield South and the other suburbs on our locations page. For sealing after repairs, see concrete sealing, and see the full repairs and resurfacing hub.
Crack repair FAQs
Fine cracks are common and often cosmetic. Wide cracks, cracks with one side higher than the other, and cracks that keep growing suggest movement and should be assessed.
Not usually. Fillers and patches seal the crack and restore the surface, but they'll generally remain visible. Resurfacing can give a more uniform look if the slab is stable.
If the slab is still moving, the crack may reopen. Flexible sealants cope with small movements. Larger movement means the cause needs addressing.
Often, yes. The sunken section can be saw-cut, removed, rebased and re-poured. The new section won't match the old concrete exactly in colour.
Yes. Cracks in house slabs, footings or walls, especially if they're growing or causing doors to stick, should be assessed by a structural engineer.
Related services
Concrete sealing → · Concrete resurfacing → · All repairs & resurfacing →
Service areas
Rowville · Noble Park North · Wantirna · Boronia · Glen Waverley · Lysterfield South · See all service areas →
Get a crack repair assessment
Send us photos of the cracks, including a close-up with something for scale, and a wider shot of the area. We'll advise on the likely options and arrange a site visit for a written quote.