Why Curbs Crack and How to Repair Them

Curbs (see here for more) are essential structural components for directing water runoff, protecting the edges of pavement, and keeping driveways and parking lots looking neat. However, curbs are often cracked or broken, and if not fixed can be a sign of worse problems. Whether you are a homeowner or property manager, knowing how curbs fail and how to repair them can save you money and time and extend the life of your pavement. Curbs are more than a cosmetic item and are structural features of your pavement system. Furthermore, broken curbs not only leave things looking professionally unfinished but may also hurt your overall curb appeal.

Common Causes of Curb Damage

Curbs are constantly exposed to weather, vehicle traffic and general wear and tear. The cumulative effect weakens concrete and causes cracking. Among the many causes of curb deterioration, the most frequent are heavy trucks and poor drainage. Curb wear can be accelerated in high traffic areas, especially near striping of parking lots or installation of a driveway paving project.

• Vehicle impact by turning or parking too close
• Weak concrete mix or initial installation in poor conditions
• Erosion from water runoff

Even new curbs may crack if the base underneath the curbing material shifts or if the concrete mixture was not properly formulated. Eventually these cracks allow more water to enter and perpetuate the damage cycle. If your curbs are adjacent to steep driveways or at locations where they receive constant or significant water runoff, you may see damage much sooner than you expect. Conducting regular inspections can give you a heads up of some potential damages before they develop into major repairs.

Freeze-Thaw Cycles and Cracks

Nashville winters may not be as bad as what is experienced in the Northern states, but the freeze-thaw cycle is still at play with respect to curbs. As water seeps into cracks and freezes, it expands and opens up the cracks. Each freeze and thaw cycle weakens the curb’s surface, which can eventually loosen it entirely.

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This type of damage is most visible at the entry points of driveways and asphalt, where water pools on the edge. Property managers who stay on top of maintaining the sealcoating and drainage on their gravel will be able to mitigate any risk to curb damage due to freeze. A property manager may have one poor winter wondering why there were no cracks emerging. By the end of spring, the cracks from one bad winter could become visually opening. The small hairline cracks from last season can become visible breaks after one or two more bad winters. That is also why it is important for professional paving contractors to emphasize the preventative maintenance of asphalt and concrete areas.

Root Damage from Trees

Tree roots are another major contributing factor in cracking of the curb. The growth of the root pushes on the concrete, and in so doing, lifts sections out of vertical alignment. This not only creates a safety hazard for the travelling public, it creates visual gaps in the edge of the pavement. Often, the offending tree is a large shade tree adjacent to the sidewalk, parking lot, or residential driveway.

When you start to see uneven or heaving curbs you may suspect some roots are down causing some disturbance to the existing concrete/pavement curb. Handling the tree issue effectively will help prevent more and more curb and gutter repair Nashville issues in the future. Depending on the levels of damage, root pruning of the tree and re-pour of uneven curb sections could help stabilize the curbs and surrounding concrete.

Likewise, there is usually a tree barrier that can often be put underground to direct the roots direction underground that will ensure they do not breach paved surfaces. Prevention is always the best method especially if you are in a new development or an HOA community where future objectives can restrict frequent forming curb issues.

Basic Repair Steps

If the damage is minimal, some cures may be doable by you, with the proper product in hand. Patching is a short-term fix, though it could prolong the curb issue longer than needed. Regular inspection will keep you ahead of small issues staying small and even let you catch potential major structural failures.

Below are some very basic steps:

• Cleaning – take away dirt and loose concrete
• Fill small spaces (crack repair with concrete patch/epoxy filler)
• For larger chips you will use a quick set concrete mix
• Smooth over and allow to cure prior to allowing traffic

While it is practical to consider doing these assures to the DIY curb survivors, they are not a long-term sustainable solution for poorly compromised curbs. To create a long-lasting situation, it is best to consult with a paving contractor that understands asphalt and concrete repairs. Having the proper tools assures in a patch system that bonds properly preventing future failures. This is especially important in commercial areas, and with pedestrian zones, where curbs must continue to provide safety for driver and pedestrian alike.

When to Consider Replacement

At times it is unreasonable to continue to patch materials when there has been a large area missing, when the damages have lifted sections of the curb to unacceptable and dangerous levels due to root damage, when edges have been crumbling away from the curb. It would be unreasonable to continue patching. Replacing the curb would restore the curb functionally and aesthetically. Additionally, to replace a curb allows a service contractor to correct any damage caused by curbs acting outside their intended meaning; the slope and water drainage could be fixed back to functional standards and aesthetics.

A good paving service contractor will maintain proper drainage, slope, and structural alignment with proper road construction standards. This is going to allow for a strong curbed pavement system to reside, preventing recurring damage. If the property manager is overseeing multiple buildings or property objectives, using curb planters for regularly scheduled curb inspections when updates are needed such as parking lot striping and sealcoating, would be beneficial for ensuring curbs remain in usable shape. Oftentimes, replacements will also allow you to avoid a potential liability from an uneven walkway or broken concrete edge.

You get a better performing curb and contribute positively to property value and appearance with good installation.