When faced with a decision as to which driveway surface works best, most Canadians choose between three options: Asphalt, Concrete and Interlocking Stone (also known as paving stones or pavers). The driveway material should fit the character of the house and the landscape. More importantly, depending on where you live, it should also stand up to heavy use. This can include snowplows, heavy water flow, road salt, vehicle fluids, and extreme heat or dryness.
Asphalt Paved Driveways
Asphalt paved driveways are very popular, providing a durable surface for parking your vehicle. In general, asphalt has the cheapest installation costs, although it needs resealing, which will cost more over time. Properly installed asphalt paved driveways have a life expectancy of about thirty or more years.
Preparing the foundation is paramount. For asphalt driveways, the foundation should be dug 12 to 15 inches deep, then 3/4 inch crushed gravel poured in up to 2 inches below grade. Then a 3 inch layer of hot asphalt is applied, which is then rolled and compacted one full inch to bring it down to grade. The edge of asphalt must be angled slightly, not perpendicular to the ground.
|Stability. Asphalt is a stable, solid material. Once cured, you can safely walk on it without worrying about mud or messy residue sticking to your shoes.||Relatively High Maintenance Requirements. Asphalt driveways require resurfacing every three to five years. The average resurfacing project costs $400 to $500 every time.|
|Aesthetic Appeal. While it’s not as stunning as stone, brick, or coloured concrete, it looks professional and finished.||Shorter Lifespan. Asphalt driveways deteriorate relatively rapidly, even with periodic resurfacing. Depending on your local climate and use rates, you can look forward to replacing your asphalt driveway every 15 to 20 years.|
|Easy Winter Maintenance. Asphalt is easy to plow during the winter. Unlike stone and gravel, both of which are prone to damage from plows, a professionally paved asphalt surface can be scraped clean and salted with little trouble. Also, it is engineered to withstand freezing and thawing.||Professional Installation Highly Recommended. Like stone, asphalt is best left to the pros. While hiring a professional reduces headaches down the road, it’s sure to swell the cost of your project.|
Poured Concrete Driveways
Poured concrete driveways are one of the preferred driveway types, offering a permanent low-maintenance driveway. While poured concrete costs more than asphalt to install, when properly sealed, it is more durable and requires less maintenance on your part. It is important to note that although concrete is more resilient and lasts longer, it will crack over time.
Concrete really shines when it is stamped or stained, instantly adding character and individuality to your driveway. Stamped concrete is imprinted immediately after the pour using a polyurethane patterned tool. There are a variety of stamps available, which mimic a variety of materials including brick, flagstone, stone, slate, or wood patterns.
For stained concrete, a base colour is added to the cement mix and then accent or release colours are added to the surface after the slab is poured. The staining can be done before or after stamping depending on the type of installation you’ve chosen. Stained and stamped concrete should also be sealed to add life to the slab.
Concrete should last 30-40 years unless it cracks. And unlike asphalt, cracked concrete is very difficult to repair. The best way to fix it is to remove the old driveway and pour a new one in its place. There are several reasons why concrete can crack but shrinkage is the main cause. As concrete dries and hardens, it shrinks. This is due to the evaporation of excess mixing water. The wetter the concrete mix, the greater the shrinkage will be. Concrete slabs can shrink as much as one-half inch per 100 feet. This shrinkage can literally pull the slab apart and cause cracks.
The best way to prevent cracking is to install control joints, which allow a concrete slab to contract as it hardens. A control joint can be the full depth of the slab or at minimum, saw cut to a depth equaling one-fourth the slab thickness (or 1 inch for a 4 inch slab). Control joints should be spaced apart by approximately 30 times the thickness of the concrete. For example, a 4 inch thick concrete slab should have control joints no more than 120 inches (10 feet) apart, preferably less. The control joints divide your driveway into several smaller slabs, each of which can contract without affecting the adjacent slab’ This minimizes the risk of cracking.
An Alternative to Concrete — Exposed Aggregate
Exposed aggregate is one the hottest trends in finished driveways. Offering a wide range of colours, sizes, and shades, exposed aggregate creates a special and attractive driveway that will enhance this part of your home.
Exposed aggregate creates a non-slip sealed surface that can last for nearly a decade with little or no maintenance. Exposed aggregate is created using special concrete mixes that combine unique aggregates that are exposed on the surface. The driveway finish reveals smooth textured stones and pebbles that are part of the concrete surface.
|Stability. Concrete is a stable walking and driving surface not prone to mud or slop.||Relatively High Cost. Concrete is second only to paving stones on this metric. Relative to asphalt, concrete’s longer lifespan and lower maintenance requirements reduce annual ownership costs.|
|Traction. Rough concrete has ample traction. Finished, sealed concrete doesn’t hold up quite as well in inclement weather, but it’s still better than polished stone.||Professional Installation Recommended. Professional installation is highly recommended for anything involving concrete.
|Easy Winter Maintenance. Concrete is easy to plow and treat during the winter. Since it’s not particularly porous, it responds well to chemical and natural ice melt, and its relatively smooth surface won’t damage plows or shovels with proper use.|
|Relatively Long Lifespan. Concrete driveways last several decades with proper care and reasonable use.|
|Relatively Low Maintenance. Other than periodic resealing, concrete driveways don’t require much maintenance.|
Interlocking Stone Driveways (Pavers)
Pavers, which start around $20 to $25 a square foot, are the most expensive investment due to material and labour costs, but the payoff is tremendous curb appeal and value. Pavers’ biggest benefit is that they should last a lifetime. The key is the fact that the pavement acts as flexible fabric, it can move with the earth, it isn’t a rigid system and isn’t prone to cracking.
Pavers offer valuable design flexibility and aesthetic impact as well. They come in a wide variety of materials including concrete, clay brick, cobblestone or natural stones. They can be laid in patterns and are shaped so they can interlock with other pavers of the same type. This also makes them easier to install without the use of mortar.
It’s important that the interlocking pavers are built over a solid base to prevent pavers from shifting; causing cracks and gaps to appear. Because pavers are porous, they can become stained over the years and might require pressure washing to remove marks from oil, tires and other contaminants. The small spaces between interlocking stones cause two problems. The slightly uneven surface makes shoveling snow difficult. And weeds can grow between stones, which may require periodic spraying with herbicide.
Polymeric jointing sand will improve the durability and stability of an interlocking driveway and can limit weed growth on a new or existing interlocking driveway. Cover the entire surface with polymeric jointing sand. Carefully sweep sand into all joints and crevasses, and then use a leaf blower to remove excess sand. Finish off by gently hosing the driveway to create a polymer seal that prevents seedlings from falling between the pavers where they can germinate and grow.
|High Aesthetic Appeal. Paver driveways look great. If boosting your home’s curb appeal is a priority, there’s a strong case to be made for these materials.||High Cost. Pavers are pricey. A top-of-the-line, professionally installed pavers driveway can easily cost up to $25 per square foot.|
|Durability. In most climates, pavers are more durable than asphalt or concrete. Though you’ll occasionally need to swap out individual pavers, you don’t need to worry about periodic resurfacing projects that increase your driveway’s lifetime ownership costs.||Slipperiness. Pavers aren’t high-traction material. In inclement weather, they’re more treacherous for pedestrians and drivers than asphalt and unfinished concrete – both rougher materials.|
|Stability. Pavers are stable and clean. Unlike dirt and gravel — which can be messy in wet conditions.||Generally Requires Professional Installation. You can try to install your paver driveway yourself, but it probably won’t turn out that well.|
Gravel Driveways (Aggregate)
A fourth option is gravel driveways, which are the cheapest. That being said, they are very dusty and require regular maintenance to redistribute gravel. In snowy Canadian winters, whether you shovel snow or use a snow blower, gravel is simply not a practical driveway choice. However, a gravel driveway can last forever because it doesn’t crack, sink or soften – it just moves around.
|Relative Affordability. Pound for pound, aggregate is the cheapest of these four common driveway materials. A basic gravel driveway can cost as little as $0.50 per square foot.||Lack of Aesthetic Appeal. Aggregate comes in many different colours and textures, some combinations of which are quite pleasing to the eye. But even high end gravel has a certain unfinished, cheap quality to it.|
|Durability. Aggregate is extremely durable. With proper drainage and regular maintenance, aggregate driveways last for decades.||Difficult Snow Removal. Gravel is no friend to snowplows, and vice versa. It’s hard to plow a gravel surface clean without dinging up the plow, spraying gravel everywhere (thereby shortening the driveway’s lifespan), or both.|
|Low Maintenance. Aggregate is low maintenance. Once the material has settled, all that’s required is periodic spreading and filling to reduce rutting and smooth bumps. The associated financial costs are minimal.||Rutting. Over time, aggregate driveways are prone to rutting. Ruts are prone to hazards like snow, ice, and mud, all of which are unpleasant or unsafe to varying degrees for pedestrians and vehicles alike.|
|Environmentally Friendly. Most driveway aggregates are naturally derived – they’re literally crushed rock, usually from the user’s geological neighborhood. Also, aggregate is naturally porous. Storm water sinks right into it rather than running off and polluting local surface water.||Potential Covenant Restrictions. If you live in a subdivision governed by a homeowners’ association, check your association’s bylaws before spending any money.|
|High DIY Potential. Installing a gravel driveway requires no great skill, just old-fashioned elbow grease. Aside from the truck driver who delivers your aggregate, you can complete the entire job from start to finish with no professional help.|
Consider All Costs, Including Maintenance
Of the three most common options for Canadians, pavers are the most expensive commonly used driveway material, asphalt driveways are the least expensive, costing approximately $12 to $15 a square foot. Concrete falls in the middle, costing about $14 to $18 a square foot.
Keep in mind the easily overlooked long-term costs. Asphalt has the lowest installation cost, though the price has gone up in the last several years as it is tied to oil prices. But asphalt is more high maintenance because it requires resealing every two to four years, which should be considered in the overall cost of the driveway.
Geography and climate play in as well – asphalt doesn’t hold up particularly well to repeated freezes and thaws, while gravel is prone to erosion in heavy rain and isn’t especially easy to keep clear during the winter.
Don’t Forget Codes, Local Regulations and Permits
If you are changing the material your driveway is made of, keep in mind that many cities will have codes requiring a permit. Before you sink any money into your new driveway, make sure it’s permitted by the powers that be. Exclusive municipalities often regulate property improvements. Homeowners’ associations can be even less forgiving, banning certain materials or colours altogether.
Whichever material you decide to go with, make sure you hire a pro to properly pave your driveway. The key to any new driveway is the careful preparation of the foundation or sub-grade. As water freezes, it expands, which can heave the ground upward causing cracks in the surface. A deep foundation that is properly compacted then filled with coarse gravel will allow water to drain effectively and extend the life of the driveway.