Road surface joint sealing

The process of sealing joints in a road surface.

Road sealing protects the joints where sections of surfacing meets and prevents damage to the road from occurring by stopping water getting in below the surface and vehicles wearing away at the edges of exposed cracks.

What happens on the day of works

On a typical day we will do the following:

  • Set up appropriate traffic management with either traffic lights or 'stop and go', so traffic can keep using the road. For narrow roads, the road will be closed and a diversion route put in place. Pedestrian access will be unaffected.
  • Clear out debris within joints.
  • Fill in joints using bituminous materials.
  • Cover the top of joints on the road surface with bituminous materials.
  • Replace any road markings that have been removed during the process.
  • Remove traffic management and reopen the road to vehicles.

Can I access my property during the work?

Pedestrian access remains unaffected during the works. If necessary, ‘no parking’ cones and signs will be placed out in advance of the work to stop cars parking in the work area which can prevent work from taking place.

Vehicle access to private driveways and off-road parking areas will be maintained where possible but we may have to limit access at some points during the process, for example when working directly outside a driveway.

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

How does joint sealing work?

Roads are usually built in sections, as most roads are too wide to be surfaced in a single pass of the surfacing machinery. This results in joints being present in the surface, usually lengthways along the middle of the road or between lanes, and sometimes across the road where the machinery has needed to stop and start.

Over time the materials in the road tend to shrink and the underlying ground can move. This results in these joints pulling apart slightly showing uniform, narrow and continuous cracks forming in the surface along the length of joints.

If left open, damage can occur to the road surface through vehicles wearing away at the edges of the joints, and significant damage can be caused to the underlying layers as water penetrates through.

Sealing these joints restores the road to being a single uniform surface, ensuring the long-term strength of the road.

Why use joint sealing instead of normal resurfacing?

Whilst traditional resurfacing does resolve the issue of open joints, as it involves digging out, disposing of and replacing the entire road surface, it is generally used when an existing road is suffering significant damage over large areas.

Open joints may exist over long lengths but they will usually be very narrow, with the road either side of the joint being in good condition. Joint sealing addresses the issue of the open joints, without needlessly and wastefully digging up and disposing of other nearby material that is otherwise in good condition.

Joint sealing is also a comparatively fast process, significantly reducing the impact of works on local communities and the travelling public when compared to traditional resurfacing.

What are the environmental considerations of joint sealing?

  • With the existing road surface left in place, reduced working times and minimal disposal of materials means work produces less carbon emissions.
  • Only a small amount of new material is added to the road, meaning minimal natural resources are used and the carbon footprint of manufacturing and transporting these materials is low.
  • No new waste material is generated by the process, waste being limited to debris that had already found its way into the joints.
  • As joint sealing is a smaller and faster job than resurfacing, saving energy and reducing carbon emissions.
  • Sealing joints extends the life of a road, avoiding the need to carry out much more energy intensive repairs.

How long does joint sealing last?

A properly sealed joint will usually last for at least 10 years, but it can last significantly longer depending on the condition of the road surrounding the joint and how much traffic uses the road.

Joint sealing will sometimes be followed up by another treatment, such as micro-asphalt or surface dressing. These two treatments combined can significantly extend the lifespan of both treatments and the road they are applied to.

Why does the road look different after joint sealing?

As the material used to seal joints is different to the material that was used to build the road around it, a properly sealed joint will still be visible.

It will remain visible over the life of the road, although the visible difference will reduce as the black colour of the sealed joint fades to a lighter grey colour over time.

Do I need to drive differently on road that has been joint sealed?

No. As soon the traffic management is removed and the road is re-opened, it can be driven over as normal. There is no bedding in process and there will be no loose materials present, so it can be driven over just like any other road.

Last updated:
22 March 2023
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