Road surface treatment works

About surface dressing

One of the ways we maintain our roads is by surface dressing. This involves treating the road surface to stop it getting worse. 

Surface dressing is a preventative treatment which seals the surface of the road to prevent water damage, makes the road safer by improving surface texture and prolongs the life of the road. It is a quick, efficient and cost-effective method which involves spraying the road with bitumen followed by a layer of stone chippings which are pressed into the road surface by a roller.

This is usually undertaken between April and August because the process needs warm, dry weather to allow the dressing to become established.

The surface dressing process

The surface dressing process is very weather dependent. The treatment cannot be applied to wet or cold roads or during high air humidity levels or very high road temperatures.

The step-by-step process is as follows.

  1. The road is swept and cleared in preparation.
  2. Bitumen is spread across the full width of the road.
  3. Chippings are spread on the road - these are embedded using a roller (the movement of traffic also helps the material to embed).
  4. Following completion of the work there will be some stone loss - this will be removed by a suction sweeper in stages with the first sweep normally taking place within 24 to 48 hours after the work.
  5. After the surface has been laid, traffic signs will be left in place advising of the risk of loose chippings and showing an advisory speed limit.
  6. When the chippings are embedded and no longer loose, any temporary signage will be removed from site.
  7. Depending on traffic levels, further sweeping may be necessary if there is continued stone loss - it can take up to six months for the road to reach its finished state.

About micro asphalt

Micro asphalt is an alternative treatment to surface dressing and is also a quick, efficient and economic method of preventative maintenance. It is a mixture of polymer modified bitumen emulsion, small aggregate and cement laid using specialist machinery and which will improve the road surface and extend the life of the road.

The micro asphalt process

The step-by-step process is as follows.

  1. The road is swept and all the ironworks (covers, gullies), are 'masked' to protect them.
  2. First, a regulating layer of material is applied to improve the surface profile of the road. This is followed by a second layer which gives the final surface. Both layers are usually applied on the same day, to a thickness of approximately 14mm.
  3. The micro asphalt layers typically take between 15 and 30 mins to dry. This is dependant upon temperature and humidity. The new surface can generally be driven on within 30 minutes of completion of application.
  4. Once the final layer of micro asphalt has dried, the masking material is removed from the ironwork.
  5. Once the work is completed, there will be some chipping loss. Warning signs and an advisory speed limit will be put in place and roads will be swept as required to remove loose material. Traffic movement assists with the embedment of the newly laid material. The new surface can generally be driven on within 30 minutes of the works completing.
  6. A few days after the micro asphalt has been laid the contractors will return to site and any low ironworks are raised.
  7. Lining will be replaced up to a few weeks after the micro asphalt has been laid to allow for sufficient embedment. This work again is weather dependant.

Proposed road surface treatment works 2022

What to expect

  • When we plan to carry out surface treatment works we will put up notices along the road to let residents when we expect to start work.
  • When work is due to start vehicles should not be parked on the road or footway.
  • When the work gets underway traffic control measures will be in place to ensure everyone's safety.
  • Surface treatment dressing works will usually be carried out between 8am and 6pm and on-street parking will not be permitted during these times.
  • The material will remain wet for between 15 and 40 minutes after it has been laid, depending on the temperature and humidity. Please do not drive or walk over roads sprayed with bitumen emulsion until the surface chippings have been spread.
  • Vehicular access to properties will be possible for most of the time, but you may experience delays while the work is either in progress or immediately after the material has been laid.
  • Drivers should take extra care and travel slowly when travelling on a road with a new surface dressing.
  • Pedestrian access to properties will be maintained throughout the works.
  • Our workforce will be happy to help if you require any assistance.
  • For a short time, particularly if the weather is warm, there may be small areas of bitumen that are still soft. If you have to walk on the new surface please take care and check your shoes before entering your house or getting into your car. Pets should also be checked in case any bitumen has stuck to them.

Want to find out more about surface dressing?

Watch the Road Surface Treatment Association (RSTA) video - YouTube - Getting a grip on surface dressing.

This video covers:

  • The surface dressing process
  • The benefits of road surface dressing
  • The aftercare process following surface dressing
  • The RSTA Road Surface Treatment Code of Practice
  • Using the road safely after surface dressing

Contact for Highway Network Services