How potholes are repaired
We tend to use two different methods for repairing potholes depending on circumstance, with the preferred approach being to cut out the affected area and fill with hot tarmac.
However, we may need to use a cold product that does not require any cutting of the existing surface in areas where working on the highway can be very disruptive or there is water on the highway.
Cut out and fill
For this method, a rectangle is cut around the border of the pothole a few inches from the edge. The area is swept to remove debris from in and around the pothole, before the edges and bottom are sealed against water ingress. Hot tarmac is then poured into the rectangle, spread tightly into each corner and compacted with a vibrating ‘whacker’.
Cold products
These products are specially designed to ‘set’ quickly and be a permanent repair while using virtually no tools. It can be used in any weather, even when potholes are filled with water as it’s used to activate the material. Cold product is also safer for the workforce and there is no waste from hot materials cooling before use.
The pothole is swept to remove debris before the repair is carried out. This material comes in ready to use bags which are poured in and shaped to the edges. The filled pothole is then either driven over or stamped level to provide a flat surface. Vibration ‘whacking’ does not work on these materials.
Repairing all potholes at the same time regardless of whether they are an immediate safety issue or not would require considerably more resources and money. Reactive maintenance is expensive compared to planned maintenance and it does not provide best value for money. Repairing roads by the pothole method costs the equivalent of £200 per square metre. Resurfacing a road costs around £30 per square metre.
To help deal with the high number of potholes and safety defects caused by winter weather at the start of 2026, we are using a range of repair methods alongside traditional asphalt. This helps us make repairs more durable and reduces the need for repeat visits.
Mastic asphalt (Roadmender) repairs
One of the methods we’re using involves a specialist machine called a Roadmender, which applies a fast‑setting material known as mastic asphalt.
The defect is first filled with asphalt to bring it level with the road surface, before a thin top layer is applied over the defect and surround to incorporate the repair to the existing carriageway.
Because the material is applied hot, it creates a strong, waterproof and long‑lasting repair. It bonds directly to the road surface, meaning saw‑cutting or heavy compaction is not needed. This also results in no visible edges, helping to reduce the risk of water ingress. The process allows repairs to be completed quickly and safely, with less time needed for traffic management.
Spray patching
We are also using spray patching, a repair method more commonly used during the summer months. This process uses air to clear dust and debris from the pothole, creating a clean surface for the repair. Cold bitumen is then sprayed into cracks and gaps to seal the defect and prevent water from getting in, before a layer of stone is applied and coated with bitumen to form a durable surface.