What is Sealcoating and Why Are We Doing it on BC Highways?

Sealcoating up close
Sealcoating on Highway 16 near Burns Lake

No, we aren’t making jackets for cold little seals, although that is a nice thought – isn’t it?

Sealcoating is actually a common type of road resurfacing done on BC highways. It involves the application of a special mixture to the road that protects the road base from additional wear and tear. So it’s kind of like a little jacket, but for roads. When it’s applied over existing pavement, sealcoating is a really cost-effective way of resurfacing that extends the life of the road by sealing out moisture. It also provides a skid-resistant, anti-glare surface during wet weather and, because it hardens the surface of gravel roads, it provides a dust-free driving surface. That’s a lot of good things coming from one type of treatment, don’t you think? We do too.

There are five or six steps in the sealcoating process:

  1. If required, we patch or seal cracks to prepare the road surface prior to sealing.
  2. A mixture of asphalt combined with water is then sprayed on the road surface. The water in this mixture starts to evaporate immediately.
  3. Immediately after spraying the asphalt-water mixture, a layer of gravel is spread over the surface.
  4. Next, the gravel is compacted and embedded into the asphalt with rollers. In some cases, sand is applied to assist in the consolidation and curing process. Despite the high-pressure rollers, some gravel will not become embedded in the asphalt.
  5. The surface is allowed to cure for up to two days while the water continues to evaporate.  Hot, dry summer days help speed this process, which is why we typically try to sealcoat during the summer months. Traffic can pass over this surface at reduced speeds during the curing process.
  6. Finally, the sealcoated surface is swept to eliminate any loose gravel. This may take several sweepings.
Sealcoating on the move
Sealcoating on Highway 16 near Burns Lake

From the time gravel is compacted on the road to the time when the excess is swept away, traffic must be kept to maximum of 50km/h. Travelling at higher speeds can cause gravel to break loose from a fresh seal coat, creating the risk of flying rock which may crack or break a windshield. To keep you and your vehicle safe, we use 24 hour pilot cars to keep the traffic speed down while the asphalt-gravel mixture solidifies. This can cause a bit of delay, which we know can be frustrating, especially if you are eager to get to the cabin or lake, but we appreciate your patience as we work to build an even better road to get you there.

Do you have any questions about sealcoating that we didn’t answer here? Let us know in the comments below or connect with us on Twitter or Facebook and we will try to get you an answer.

Page 1 of 108 comments on “What is Sealcoating and Why Are We Doing it on BC Highways?”

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  1. Awful .
    Had to drive between Rock Creek and Kelowna two weeks ago. As soon as we got beyond the pilot car area and drove on what was suppose to be done I had gravel hitting me from the car in front and some cars going by.
    I now have a cracked windshield plus two more chips as well as chips all over the hood and fenders. The rocks are so sharp they broke right through the clear coat and the paint. Who’s going to pay for all that. Oh right ME. Thanks Seal coat ,great job. NOT

    Reply
    • Hi Bruce, we followed up with the ministry rep for the project in regards to the loose rock on Highway 33. Typically, after a seal coat has sufficiently cured, a contractor will sweep the affected area and allow pilot car controlled traffic to further consolidate the aggregate. After this process the contractor sweeps the entire pilot car controlled area once again removing some dislodged material in preparation for the application of temporary center-line marks and if the seal coat appears to be stable, the contractor will release the traffic to reduced or posted speeds. After a couple of days of unobstructed traffic some material collects on the shoulders and the contractor cleans this off as well. The amount of aggregate that comes loose after a seal coat is released to traffic at posted speed is a function of the rock embedment and overall strength of the seal coat. For this reason, the Ministry addresses all vehicle damage to the contractor’s attention in hopes that the complaint gets resolved.

      We’ve recently inspected Highway 33 and additional sweeping has been requested.

      Vehicle damage claims can be sent to: Arrowsmith Road Maintenance Ltd.: 250-652-5535

      Reply
  2. I bicycle with a few other people down highway 33 to Grand Forks every year from Kelowna. I drove it on June 25th and it felt like I was driving on gravel road the on the way from Rock Creek to Beaverdell.. I am not sure what portion of the highway was completed because it all felt the same in the speed controlled area and non speed controlled area.. rough!! My question is how will the shoulders and road be when the job is complete and will it be bicycle friendly.

    Reply
    • Hello Cary,

      We spoke with the area manager who informed us that the road will be completed next week, and while it won’t be as smooth as a paved surface, it does provide a skid-resistant surface and will help the road from aging prematurely. The shoulders will be smoother but will be in generally the same condition they were in in prior to the sealcoating. The Kettle Valley Railway/ Columbia and Western Railway routes is a great alternative to the highway and has a maintained cycle path that crosses between Kelowna and Grand Forks. This route is not paved but it is a good maintained gravel route with many spectacular views and some fantastic history detailing the early days of rail transportation in the area. Here is the link: http://www.kettlevalleyrailway.ca/

      Hope that this helps!

      Reply
  3. I’ve heard a lot about seal coating being good for the life of roads. It even looks better that way! It does make the road a bit rougher at times, but I definitely think it’s worth it to extend the life of the road. After all, building a whole new roads causes a lot bigger of a delay than a seal-coating process. Thanks for the information!

    Reply
  4. I am very sad to hear you are sealcoating the southern half of Highway 33 next week. The resulting abrasive surface will make it impossible for me to ride my motorcycle on it without shredding it’s tires. In my experience sealcoating always make a terrible road surface. It’s extremely abrasive and noisy and hard on tires. I wish you would just lay down a layer of nice smooth asphalt.

    Reply