A hairline crack of about 1/8 inch in a concrete driveway can usually be filled with flexible sealant before winter. Wider cracks, or a slab where one side sits higher than the other, need a contractor to find the cause first.
Aurora's driveways come in two very different shapes. Around the older streets near Yonge, a driveway is often a narrow strip beside a mature tree with decades of roots under it. In the newer northeast subdivisions, it can be a wide, long slab that carries two or three cars. Both crack, for different reasons, and the repair that suits one can be wasted money on the other. This guide covers what a crack is telling you, what you can fill yourself, what to do about salt, and the Town's zoning rules that matter the moment a repair turns into extending or widening the driveway.
Read the crack before you fill it
Three things decide whether a crack is a sealant job: its width, whether the two sides are level, and whether it is still growing. Concrete Network, an industry reference for concrete contractors, puts the do-it-yourself line at about 1/8 inch: a crack that thin may be something you can handle yourself, and anything wider is worth a contractor's opinion because it can signal a bigger stability problem.
- Hairline to about 1/8 inch, slab level: a normal shrinkage or settling crack. Clean it out and fill it.
- About 1/2 inch or wider: the same reference says to set a foam backer rod or sand into the crack before filling, and that significant cracks may need a professional.
- One side higher than the other, or the crack keeps lengthening: the slab is moving. Filling it hides the symptom and the crack returns.
Mark the ends of a crack with a pencil and a date. If it has not moved by spring, it was probably done moving.
Sealant, epoxy or something bigger
A flexible crack sealer, usually sold in a tube for a caulking gun, is the default for a thin driveway crack because it stays bonded as the concrete expands and contracts through an Ontario year. Epoxy filler is also suited to cracks around 1/8 inch or smaller, but it hardens fast and it is rigid. If the cause is movement, the concrete will simply crack somewhere else. Read the label for the temperature range the product can be applied in; late October mornings can fall outside it, which is a good reason to do the job on a dry, mild afternoon rather than wait for a better week that may not come.
Why this slab cracked
A few small cracks after many years are normal; eventual cracking in concrete is close to inevitable. A driveway that cracked within a few years of being poured points elsewhere. Concrete Network lists too much water in the mix and too few control joints as common installation causes, and large tree roots near the slab as a separate problem that should be dealt with before any repair. That last one matters in Aurora's older neighbourhoods, where mature trees sit close to the pavement. Filling a crack that a root is still pushing open is a short-lived fix.
On a big northeast Aurora driveway, ask where the saw cuts are. A long slab with few control joints will crack along its own line sooner or later, and a contractor who knows that can sometimes cut a joint where the slab wants to split instead of fighting it.
Do it before winter
Water is the damage mechanism. Concrete Network notes that a cracked surface is at greater risk because water enters the cracks and exerts enough pressure when it freezes to widen them. Repairing before winter arrives is the standard advice for exactly that reason.
Salt is the second half. Sources aimed at homeowners advise skipping de-icers entirely the first winter after new concrete goes in, since new concrete is more susceptible to salt, and using sand for traction instead. Fertilizer-based de-icers (ammonium nitrate or ammonium sulfate) react chemically with concrete and should not be used at all. If your driveway was recently poured or resurfaced, plan for a shovel and a bag of sand rather than a bag of salt.
Walkways, the apron and the Town's part
The walkway from your door to the driveway is on your lot, so its cracks and trip hazards are yours to repair. The strip between your lot line and the road is different: the sidewalk, curb and the driveway apron that crosses the boulevard sit on the Town's road allowance. We could not find a page on aurora.ca that sets out what a homeowner may repair there, so call the Town before you cut, patch or replace anything past your property line. Anything you dig deeper than a surface patch needs utility locates first; Ontario One Call arranges them.
The width rules, if repair turns into widening
Patching a crack changes nothing about your driveway's footprint. Extending it, or replacing it wider than it was, does. The Town of Aurora Zoning By-law 6000-17 (section 5.6.1, in the January 2024 consolidation of section 5) sets the maximum driveway width for residential lots with fewer than five parking spaces by lot frontage:
- Frontage under 9.0 metres: 3.5 metres.
- 9.0 metres to under 18.0 metres: 6.0 metres.
- 18.0 metres or more: 10.0 metres, but never more than 6.0 metres at the street line.
- Estate Residential and Rural zones: no maximum width, but still no more than 6.0 metres at the street line.
The same section says a driveway can be no narrower than 2.7 metres, allows one driveway access per residential lot (a second only on lots with 25.0 metres of frontage or more), requires a hard, stable surface outside Rural zones, and says vehicles may only be parked in a yard on a properly constructed, drained hard-surface driveway. Wider than the limit means a minor variance from the Committee of Adjustment, and the Town has published notices for owners asking for a 10-metre width at the street line on a lot where 6 metres applies. Measure your frontage and your current width before you let a contractor pour a bigger slab.
If you are in the Aurora Heritage Conservation District, ask the Town's heritage staff before changing a front-yard driveway surface or layout; heritage rules were outside what we could confirm for paving.
What to ask before you hire
- What do they think caused the crack, and does the repair address it or just cover it?
- Is the price itemized by crack length, any slab replacement, and disposal?
- If they quote a wider or longer driveway, have they checked it against your lot frontage?
- Will they call for utility locates if they dig?
Prices vary with how much needs cutting out versus filling, and we have not quoted a figure here because the cost sources we could check did not reliably cover Ontario. Get two or three written quotes and compare what each one actually includes.
Quick answers
Can I fix a cracked concrete driveway myself?
Yes, if the crack is about 1/8 inch wide or thinner and the slab is level on both sides. Wider cracks can point to a bigger problem, so have a contractor look first.
Should I use sealant or epoxy on a driveway crack?
For a thin crack, a flexible sealant is the usual choice because it stays bonded as temperatures rise and fall. Epoxy filler suits small cracks of about 1/8 inch or less, but it is rigid, so if the slab keeps moving the concrete can crack again nearby.
How wide can I make my driveway in Aurora?
It depends on your lot frontage: 6 metres for lots 9 to under 18 metres wide, 10 metres for 18 metres or more, and never more than 6 metres at the street line. Estate Residential and Rural zones have no overall cap but keep the 6-metre street-line limit.
When should I repair driveway cracks in Ontario?
Before winter. Water that gets into a crack and freezes can push it wider, so a crack you ignore in October is usually bigger by April.
Can I use road salt on a new concrete driveway?
Avoid de-icers the first winter after new concrete is placed, because it is more vulnerable to salt. Use sand for traction instead, and never use fertilizer-type products like ammonium nitrate, which react with concrete.
Related reading
- More home repair guides for Aurora
- All Rhodex services: get a fixed price
- Deck and Fence Repair on a Larger Northeast Aurora Lot
- Exterior Repairs in Aurora's Heritage District
- Foundation and Basement Crack Sealing in Older Downtown Aurora
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