Why cold mix repair works
Cold mix asphalt is pre-blended polymer-modified bitumen and graded aggregate that stays workable at ambient temperature. Unlike traditional patching, it bonds chemically and mechanically to the surrounding pavement without heat, primers or specialist plant.
Tools and materials
- Bag of cold mix asphalt (5, 7, 10 or 14 Gauge depending on depth)
- Stiff broom or wire brush
- Square-mouth shovel
- Hand tamper, plate compactor, or simply the wheel of a vehicle
- Optional: tack coat for very smooth substrates
Step-by-step
- Clear the defect of loose aggregate, water and debris.
- Square the edges with a saw cut or shovel for a clean bond face.
- If the hole is deeper than 50 mm, fill in lifts — compact each layer before adding the next.
- Overfill the patch by 15–20% to allow for compaction.
- Compact firmly from the edges inwards using a tamper, plate or vehicle wheel.
- Sweep away any surface fines. The patch is trafficable immediately.
Choose the right grade
Use a 5 or 7 Gauge mix for shallow patches and tight finishes, and 10 or 14 Gauge for deep, heavy-traffic holes. Mixing grades in lifts is fine.
Common mistakes to avoid
- Skipping the clean-out — debris kills the bond.
- Under-compacting the surface — leads to ravelling and water ingress.
- Filling deep holes in a single lift — the centre will not compact properly.
- Leaving the patch dished — water pools and accelerates failure.
After the repair
Modern polymer-modified cold mix continues to cure under traffic, becoming harder and denser over the first few weeks. There is no need to barrier the area or wait — open it to traffic as soon as compaction is complete.
Frequently asked questions
How deep can I fill a pothole with cold mix?
There is no maximum depth — just fill in 50 mm lifts and compact each layer. For very deep holes, use a coarser grade like 14 Gauge as the base course.
Do I need a primer or tack coat?
Not for normal pavement repair. Tack coat is only useful when bonding to very smooth surfaces like polished concrete or steel covers.
How long before I can drive on the repair?
Immediately after compaction. Cold mix has no cure delay.
