Cracks are the earliest warning sign on any asphalt surface. On their own they do little harm. The problem is what gets into them: rainwater. Once water reaches the base layer, it softens it, traffic starts to pump material out, and within a season or two a crack becomes a pothole or a sunken patch. Sealing cracks is one of the cheapest things you can do to extend the life of a driveway, parking area or private road.
Why asphalt cracks
There are several common causes, and knowing which one you have helps decide the treatment:
- Ageing and oxidation. The Western Cape sun hardens the bitumen over time, making the surface brittle. You see fine, random cracks and a faded grey colour.
- Thermal movement. Asphalt expands and contracts with temperature. Long straight cracks across a surface are often thermal.
- Joints and edges. Cracks often open up where two pieces of asphalt were laid at different times, or along an unsupported edge.
- Clay movement. In areas with expansive clay soils, the ground swells in winter and shrinks in summer, cracking the surface above it.
- Base failure. Interconnected “crocodile” or “alligator” cracks over an area show that the base has lost strength. These need a pothole-style repair, not just sealing.
Our crack sealing process
- Assess. We walk the surface, mark the cracks suited to sealing and identify any areas that need patch repairs instead.
- Clean out. Cracks are cleaned of dirt, vegetation and loose material using wire brushes and compressed air, so the sealant can bond to clean, dry edges.
- Rout if needed. Wider or irregular cracks may be routed to give a uniform reservoir for the sealant.
- Seal. A flexible bitumen-based crack sealant is applied into the crack and finished slightly over the surface so it bridges the edges.
- Blind. Where needed, the sealant is dusted with sand or fine material to stop it tracking on tyres while it sets.
How long does crack sealing last?
Crack sealant moves with the asphalt and stays flexible, but it does age. Depending on traffic and sun exposure, sealed cracks typically need checking again after a few years. Sealing is a maintenance task, and for larger sites we recommend a simple annual check before winter.
Crack sealing as part of a bigger job
Crack sealing is also an essential step before:
- Slurry seal. Cracks are sealed first so the slurry does not simply bridge them and crack again.
- Resurfacing. Cracks in the old surface are sealed before an overlay to reduce reflective cracking through the new layer.
Who uses crack sealing
- Homeowners with a driveway that is starting to show its age.
- Bodies corporate and estates looking after internal roads on a limited budget.
- Businesses, schools and churches with large parking areas.
- Farms with long private access roads where full resurfacing would be very expensive.
What it costs
Crack sealing is usually priced per linear metre or as a lump sum for the site, depending on how much there is. It is a small fraction of the cost of resurfacing. Our pricing guide explains how maintenance compares with a full rebuild.
Can I seal cracks myself?
Small DIY crack fillers are sold at hardware stores and can help on a hairline crack. For anything wider, or where cracks cover a large area, the cleaning and preparation make the difference, and that is where most DIY repairs fail.
Arrange an inspection
Send us a few photos on WhatsApp or book a free site survey. We will tell you whether sealing is enough or whether some areas need repairs, and you will have a written quote within 24 hours.