When you arrive at a seal coating project on a Saskatchewan highway--slow down! Travel at posted speeds.

Traffic movement, especially at higher speeds can cause stones to break loose from a fresh seal coat. This creates the risk of flying stones. Stones thrown from your tires may crack or break a windshield. By slowing down you decrease the chance of damage from stones that may be thrown up by other vehicles. By slowing down you also protect your vehicle.

The normal practise for routine maintenance sealing is to erect temporary signing and traffic control devices in advance of seal coating projects. Major projects may be controlled by flagpersons and pilot vehicles from both directions.

Most seal coating is done in the spring and early summer before the heavy tourist traffic season. Weather permitting, projects can occur through autumn

Seal coats are used extensively on the thin asphalt highways that make up half of our highway system.

• Seal coats provide a waterproof surface and prevent moisture from entering, then weakening the roadbed.
• Seal coats reduce deterioration and cracking of the asphalt surface and prolong the life of the pavement.
• Seal coating prevents failures on pavements and is used where failure has already started.
• Seal coats provide an improved non-skid surface in wet or icy conditions.
• Seal coats provide an anti-glare and increased reflective surface for night and wet weather driving.
• Seal coats provide a dust free surface on low volume roads.
• Seal coating defers expensive repaving. Seal coats generally last three to five years.

In the five step seal coating process, about 5 mm of hot liquid asphalt is sprayed on the road surface. Immediately after the liquid asphalt application, crushed gravel chips are spread over the asphalt. Rubber tired rollers then pack the gravel into the asphalt. The seal coat is left to cure for up to 24 hours. This may take much less time on low volume traffic roads or for small spot sealing.

The loose gravel is swept off after curing. This may require up to three sweepings.