An Introduction to Driveways and Sidewalks

Driveways, walkways, and sidewalks often go unnoticed until something goes wrong. We expect these surfaces to be smooth, safe, attractive, adequately sized, and fairly maintenance-free. But errors with installation, combined with Mother Nature’s relentless weathering forces, can make these important pathways problematic.

While sidewalks in urban and suburban areas are typically governed by specific regulations, the construction of residential driveways and walkways is not usually constrained by building codes. The responsibility for getting these details done right falls on the shoulders of homeowners and the contractors who complete the work.

Materials Make a Difference

A dirt pathway may be the most natural way to walk from one place to another, but it’s usually the least desirable from a homeowner’s point of view. Who wants to deal with an irregular surface that will be muddy in wet weather and icy on cold winter days? A gravel walkway is a significant step up from bare earth, providing improved drainage, traction and delineation from surrounding lawn areas. But gravel has its limitations, too: It will spread outside the pathway unless it’s confined inside some sort of edging detail. You’ll need to replenish the gravel as it works its way into the soil or spills out of the pathway.

If a gravel path isn’t to your liking, steppingstones offer an attractive upgrade from a dirt track. You can use natural stones, or stones made of concrete. Just make sure to space stones for a safe, comfortable stride, and to bed them solidly so there’s no wobbling. Your steppingstones can be surrounded by gravel, or just grass.

Concrete pavers have become very popular, not just for walkways, but also for driveways, patios, and pool surrounds. These factory-made paving stones come in different shapes and sizes, and even in different colors. They are much more affordable than natural stone, and much easier to install because you’re dealing with uniform thicknesses and shapes. You can find contractors who specialize in concrete paver installations, but these pavers are easy for DIYers to install, too. The key to a successful installation is proper preparation of the base –compacted soil, covered with a layer of compacted stone dust.

Asphalt (blacktop) is a popular material for driveways and walkways. Asphalt pathways are easy to use in all weather conditions and can last for decades if properly installed and maintained. The downsides include the potential for damage by heavy vehicles, especially during hot weather. Turning the wheels of any stationary vehicle on hot asphalt can damage the asphalt. Regular maintenance is highly recommended, including sealing cracks and sealing the entire driveway with a high-quality asphalt sealer. Sealing asphalt can be a DIY project.

Driveways and walkways can also be made from poured concrete. In hot, sunny weather, concrete won’t overheat and soften like asphalt can. But it can crack and heave when the ground freezes; that’s why it’s best-suited to warmer climates. Whether you’re creating a driveway or a walkway, concrete is more challenging to install than asphalt. Because of its weight and brittleness, concrete demands a stable, well-drained base, reinforcement with welded wire mesh or other materials, and control joints to avoid random cracking due to normal expansion and contraction. On the plus side, concrete is a user-friendly material. Small projects like walkways are well within a DIYer’s capability. It’s even possible to cast your own concrete pavers, using home-made or store-bought forms.

Concrete can be installed and finished to provide an appearance other than the usual dull light gray. Coloring can be added to give the concrete a more upscale appearance. Various finishing techniques can create designs in the concrete from simple patterns to complex shapes that can appear similar to brick and stone.

Take Care with Elevation Changes

Steps are sometimes necessary to get from a lower elevation to a higher elevation over the run of a walkway. The steps can be built using concrete blocks, bricks, preservative-treated wood, railroad ties, and concrete. In all cases, careful installation is required, to ensure consistent height and tread dimensions and treads that are level. Although a railing may not be required by your local building code, it’s always good for a stairway to have this extra safety feature.

When a sloped driveway is called for, it’s important to anticipate drainage requirements so that water can move away from the house and off the driveway without damaging other parts of your yard.

Good Installation Makes a Difference

Installation techniques for driveway and walkway materials depend on the material. For example, pavers should be installed according to the paver manufacturer’s instructions. There are, however, some general installation rules that apply to most driveway and walkway materials.

Driveway and walkway materials are supported by the soil under the materials. It’s important for avoiding cracking and settlement that the soil under the materials is solid and properly compacted. Any base material, such as sand under pavers, should also be properly compacted. For small projects, a hand tamper can work. For larger projects, a mechanical tamper saves a lot of hard work. Both types of tampers can be rented.

Driveways and walkways should slope away from the house, and should slope to drain over their entire run. Failure to provide adequate slope can lead to wet and damaged foundations, deterioration of the driveway and walkway, and low spots where water collects. Ponding water can be a slip hazard, especially in the winter when the water freezes.

The minimum slope for solid and even materials, such as asphalt and concrete, is about a two-percent slope. Uneven materials, such as pavers, may need more slope to properly drain. Refer to the paver manufacturer’s instructions. More slope than the minimum is okay, up to a point. Slope that is too great can be difficult to drive on and walk on, especially in the winter.

When installing walkways near the house, be sure to provide a means to drain water that collects between the walkway and the house. This is especially critical if downspouts discharge in this area. The ground should slope away from a house at least six inches in the first ten feet. The walkway height should be set to provide this minimum slope, and not trap water between the walkway and the house.

Driveways and walkways should provide good traction, especially when wet. The surface should be textured enough to provide this traction. Smooth materials should be avoided on most exterior surfaces.

Make Sure to Get Your Dimensions Right

A driveway should be wide enough to provide access for all vehicles that might need access to the house, including trucks. The minimum recommended width for a straight residential driveway is ten feet; wider is better. Add at least two feet where the driveway curves. If the driveway provides access to a side-entry garage, there should be at least twenty feet in front of the garage to allow turning into the garage. Deeper is better, especially if long cars or pickup trucks are anticipated.

A walkway should be wide enough to allow two people to walk side-by-side. The minimum recommended width for a straight residential walkway is thirty-six inches. Forty-two inches is better. Add at least twelve inches where the walkway curves. If the walkway terminates into steps, the walkway should be as wide as the steps where it meets the steps, and for several feet away from the steps.

Expecting and Correcting Different Defects and Repairs

Common defects in driveways and walkways include uplift, settlement, and cracks. Uplift is usually caused by plant roots, such as the roots of large trees. Roots of many trees can spread out at least as far as the tree canopy, so it’s best not to have driveways and walkways where the tree canopy overhangs the driveway or walkway. The best repair for root uplift is to stop it before it causes too much damage. At the first indications of root uplift, find and cut the root. Note that this could injure the plant.

Settlement is usually caused by improper compaction of the soil under the driveway or walkway, or by erosion of the soil around the driveway or walkway. This erosion is usually caused by improper driveway slope, or by improper grading of the soil around the driveway or walkway. Repair of settlement depends on the driveway or walkway material, and on the size and depth of the settled area. For large and deep settlement of a concrete driveway or walkway, a contractor may be able to inject material under the driveway or walkway to raise it back up to its proper level.

Causes of cracks depend on the driveway or walkway material, and on the installation quality. Most people learn to live with cracks in concrete that are less than ¼ inch wide, or that present less than ¼ inch of vertical displacement. Wider concrete cracks can be filled with materials, such as concrete repair caulk, up to the width specified by the caulk manufacturer. Concrete that presents more than ¼ inch of vertical displacement can be a trip hazard, and should be addressed. The concrete can be ground down at the displacement to make the surface more even. Concrete grinders can be rented.

Before spending a lot of time and money on repair of driveway and walkway defects, it’s prudent to determine the cause of the defect. The defect could recur unless the cause is identified and addressed.

Projects and Professionals

Driveway installation and replacement projects are usually best left to qualified contractors. The labor, equipment, and expertise with the materials are beyond the capabilities of most homeowners.

Projects involving asphalt, and projects involving more than one or two cubic yards of concrete, are also best left to qualified contractors. Asphalt installation requires special equipment and expertise. Working with large amounts of concrete is labor-intensive, and requires some expertise.

Projects involving pavers and wood are well within the capabilities of DIYers. These projects require some skill, and the ability to follow manufacturer’s instructions to the letter. They can also be very labor intensive without power equipment, some of which can be rented.
Driveways and walkways are often utilitarian structures that are expected by home buyers. They can reduce the value of a house if in poor condition, but because they are expected, utilitarian structures add little value to most houses.