Road micro-asphalt resurfacing

The micro-asphalt surface treatment process for road surfaces.

Micro-asphalt is a material used to provide a new surface layer to an existing road. It contains bitumen emulsion, fine aggregate, cement and water. It is a surface treatment applied over an existing road surface. This differs from resurfacing which removes and replaces the old surface.

What happens on the day of works

On a typical day our staff:

  • close the road to vehicles using traffic management (signs, cones and so on) - pedestrian access is unaffected
  • mask ironworks (drains, manhole covers and so on) with tape and sweep the road to remove debris
  • use specialist machinery to lay the micro asphalt base coat directly onto the road
  • lay a second coat of micro-asphalt on top of the first, either on the same day as the base coat or the following day
  • remove tape used to mask ironworks - some may be left covered intentionally and further information about this is available in the frequently asked questions below
  • place signs out warning road users to take care until we can reinstate road markings
  • remove traffic management and reopen the road to vehicles.

Follow-up works in the days and weeks after

Additional works take place on the road in the weeks following the micro asphalt surfacing. Timescales may vary due to weather or operational requirements, but usually take place as below:

  • within one week - the road will be swept to remove loose stone
  • within 2 to 4 weeks - we will raise any ironworks that are lower than the new surface to the correct level and those left covered by the new surface will be uncovered and raised
  • within one month - we will replace all road markings that were on the road prior to the laying of the new road surface.

Can I access my property during the work?

Pedestrian access remains unaffected during works and we:

  • close the road to vehicles to stop cars from parking on the road as this can prevent work from taking place
  • maintain access to private driveways and off-road parking areas where possible
  • may have to limit access at some points within the process, for example when the surface is fresh.

If you have specific access needs, speak to the workforce on site who will assist you.

How does micro-asphalt work?

Water penetrating lower levels of a road causes potholes and other structural failures. Micro-asphalt seals the surface of a road, preventing water entering minor defects. These include non-structural cracks, utility works, minor rutting and previous repairs to the road.

Why use micro-asphalt instead of normal resurfacing?

Micro-asphalt and normal resurfacing serve different purposes.


Laying micro-asphalt is a preventative measure. We lay micro-asphalt to a road before it suffers significant damage to extend it's life. We may use it in situations where a road surface might still look to be in reasonable condition.

When used at the right time, laying micro-asphalt delays the need to do more significant work minimising disruption to residents and road users.


Resurfacing takes place when the road has significant or structural damage already, requiring the damaged material to be removed and replaced. Because of this, resurfacing works are a bigger job than surface treatments and cause more disruption to residents and road users.

What are the environmental considerations of using micro-asphalt?

  • With the existing road surface left in place, reduced working times and no need for disposal of materials means work produces less carbon emissions.
  • There are no waste materials needing recycling or disposal.
  • The quantity of natural materials used is small and there are less carbon emissions from transport because micro-asphalt is used in thin layers.
  • Micro-asphalt is a 'cold mix' material, it's safer to use than 'hot mix' materials and there are energy savings as there is no need for heating during producing and transporting.
  • Micro-asphalt is not produced using dangerous chemicals so contact is safe for humans and wildlife.
  • Applying a treatment is a smaller job than resurfacing, saving energy and reducing carbon emissions.

How long does micro-asphalt treatment last?

This surface treatment prolongs the life of a road by up to 10 years. This can be longer if heavy vehicles do not use the road often.

How long do I have to wait before I can drive on it?

Traffic can usually use the surface 20 to 30 minutes after application. This time varies depending upon conditions as the process is weather dependant.

Follow the directions of the workforce on site. They will determine when the surface is usable and remove signs and cones as necessary.

Why does it look coarse and unfinished?

This is normal. Micro-asphalt is unusual in that it takes some time to cure and bed-in. It's appearance changes as this occurs. When first laid, it will look very dark, feel soft underfoot and have a rough texture.

During bedding-in, the surface lightens in colour, solidifies, and becomes smooth. In the end, it will look like a typical road. The bedding-in process takes around one to three months. This can vary depending on weather conditions and the amount of traffic using the road. The more traffic, the faster the road will bed-in.

Marks are occurring on the new surface. Is this normal?

Yes. The new material is soft when laid and therefore marks easily. The most common cause is stationary vehicles turning wheels as they manoeuvre into a parking space or driveway, leaving tyre tread imprints on the surface.

These marks can look quite significant, however they usually do not impact the strength or longevity of the new surface. Marks fade with traffic use of the road as the material beds-in. The only way to prevent marks is to close the road for the whole bedding-in period which is not a realistic option.

There is loose stone on the surface. Will you clear this?

We sweep the road at least once shortly after laying the new surface and will carry out further sweeps as necessary.

A drain or manhole cover is still masked, is this right?

Following the work, some ironworks (drains, manhole covers and so on) may be lower than the new surface. If this is the case, the ironworks will remain covered to minimise risk of damage to passing traffic.

This is a deliberate and temporary measure. Around four weeks after the works, we will raise the ironworks to the correct level and remove any masking.

When will you replace road markings?

  • We usually reinstate road markings around one month after laying the micro-asphalt surface.
  • We may replace them in stages.
  • We are likely to replace safety-related markings such as give way lines first.
  • We replace yellow lines separate to white lines.
Last updated:
22 March 2023
Share this