Quick Driveway Paving Guide for Minnesota Asphalt Driveways

The success of any construction project begins with the foundation, and building a new driveway is no exception. If the foundation, the sub-base below the asphalt, is not built correctly, you’re bound to have problems in the future. This sub-base is the true foundation for your driveway, which has two primary jobs:

• It provides a stable surface to support the pavement
• It provides a frost barrier to help reduce winter damage due to freezing and thawing.

Much depends on the soil conditions at your site when designing a sub-base for your driveway. In some areas, a well-drained, sandy soil can act as its own sub-base without modification. In other areas where clay or other poorly compacted soils exist, a brand-new sub-base must be laid. Where there is an existing driveway, a poorly designed or contaminated sub-base may have to be completely removed and replaced. No single solution will work in every case.

When preparing a base for paving, focus on the following: subgrade, drainage, base thickness, base stability, dimensions, and compaction. The sub-base should be at least 4 inches thick. The intended use of the driveway will determine the thickness of the base. For standard driveways used by regular cars and SUVs, a base thickness of 4-6 inches is sufficient. For heavy equipment, trailers, or trucks, a thicker base is recommended.

A properly compacted base is crucial. The best type of base is Class 5 limestone or recycled Class 5 made out of concrete bituminous (con-bit). This mix is highly compactable and strong. A vibratory drum roller is preferred over a static roller for compacting the base, as it achieves the highest compaction density by compacting the base material from the bottom up. A vibratory plate compactor will be used in areas inaccessible to the rollers.

The surface of the compacted base should be smooth, with a maximum tolerance of ±3/8 inch over a 10 ft straight edge. And finally, the base must be firm and ready before paving. On occasion, especially if the base is 6 inches or more, additional time may be needed for the base to firm up.

The paving contractor should develop a drainage plan for your driveway. Each driveway is different. Driveways vary; some slope from the garage to the street, allowing water to drain easily. Others may have negative drainage, where the street is higher than the garage. In these cases, a swale in front of the garage is necessary to redirect water to the sides, keeping it out of the garage.

Some driveways, particularly those with detached garages, need a drainage plan to direct water away from the house and yard, ideally towards the street. Drainage plans can vary in complexity, so it’s crucial to design and build them properly. Discuss these drainage issues with your driveway contractor before any work begins. At Richfield Blacktop, we have over 60 years of experience tackling complex driveway drainage problems.

The hot mix asphalt for your driveway is an engineered mixture of stones, sand, and a petroleum product called liquid asphalt cement. Varying sizes of this stone-and-sand mixture, called aggregate, are heated and then mixed in exact proportions with liquid asphalt cement heated to 300 degrees.

While the mixture is hot, it is delivered to your driveway and applied to the prepared sub-base with a self-propelled paving machine. This ensures the asphalt is applied to a consistent, even thickness, creating a smooth, even, attractive paved surface. Richfield Blacktop’s paving machines will do a great job for you.

Asphalt hardens quickly and can typically be walked on within an hour. Depending on weather conditions, you should wait at least 3 days to drive on it. Asphalt cures over time, becoming softer and more flexible when warm. As it ages, it loses some of its oil and becomes less flexible. If paved in the fall, the curing process halts in winter and resumes in spring.

• Strength and Durability – That’s why it’s used on so many roads.
• Withstands Freezing & Thawing – Crucial factors in Minnesota.
• Unaffected by Salt – Unlike concrete, asphalt isn’t damaged by salt.
• Flexibility – Asphalt is resistant to winter damage caused by freezes and thaws.
• Cost Effective – Asphalt is economical, compared to other paving materials.
• Melts Snow Fast – The black color melts snow, whenever the sun shines.

In some cases, it is possible to overlay an existing asphalt driveway with another layer of asphalt. This can save money over a full driveway replacement. However, this is rarely done for two reasons:

1. Anywhere there are existing cracks or where the asphalt is broken up will “reflect” through the new layer.
2. Drainage may be disturbed. Adding a layer of asphalt raises the height of the driveway. Unless your driveway has sunk in front of the garage or along the street, the new layer will be higher and may cause drainage problems. To address these problems, we can mill out specific areas, but for smaller driveways, complete replacement is often the better option. Fewer than 5% of our customers choose overlays.

The bottom line is that in some instances, an overlay will work. When a professional driveway consultant from Richfield Blacktop visits, they will thoroughly evaluate your driveway and make recommendations on your paving options. You can rely on their advice for your particular situation.

Every driveway, regardless of the materials used, requires care and maintenance to ensure its long life and beauty. Over time, your driveway may develop cracks or sustain damage, and prompt repairs are needed to prevent further damage. Proper sealing is important, too, periodically. You can learn more about driveway care and maintenance on our website.

At Richfield Blacktop, we prioritize educating our customers as part of our top-notch service. The more our customers know, the better able they are to make the best decisions about their driveways. Since 1954, we’ve been helping our customers make the right decisions for their property. Our goal is to ensure every driveway we build offers lasting beauty and functionality. Contact us today to schedule a visit from one of our expert driveway consultants, who will answer your questions and guide you in choosing the best materials and techniques for your specific property. Every driveway and property is unique, and Richfield Blacktop’s long experience and highly trained driveway consultants are your assurance of a great driveway for your home or commercial property.