Parking Garages: How to Maintain these Valuable Assets
Parking garages play a critical role in many commercial and residential settings. However, despite their importance, they are often neglected and allowed to fall into disrepair.
Why does this happen? Sometimes the reason is financial. When budgets are tight, building owners tend to focus their resources on more visible initiatives inside the building — projects like common area upgrades and tenant finish work that are more likely to impress prospective tenants or residents and please existing ones. Another reason is the adage “Out of sight, out of mind.” A building owner may rarely, if ever, spend time in the parking structure and therefore doesn’t see that repair work is needed.
What are the consequences if a parking facility is not maintained? First, if damage progresses, the cost to make repairs increases exponentially every year. And, as the level of degradation increases, so does the risk of legal liability for injuries or property damage. What’s more, in the long term, widespread visible decay can decrease the value of the property.
Common Signs of Distress in Parking Facilities
There are two primary indicators that a parking garage is in need of closer inspection and potentially repairs. They are:
- Cracks. There are multiple types of cracks. For example, radial cracking takes place around a column, and is important to be aware of. When cracks occur anywhere in a parking garage and show water staining, especially if there is a red or rust color that indicates corrosion, this is also a sign of a significant problem.
- Spalling. Spalling is a term for when fragments of concrete are detached from the larger mass. A “spall” is actually the circular or oval depression left by a missing piece. This condition is particularly important to address if the spall exposes reinforcing in the concrete.
If either or both of these conditions exist, it is important to have an engineer or concrete contractor perform a thorough evaluation of the structure.
How a Parking Garage is Evaluated
The evaluation of the structural integrity of a parking garage starts very simply with a walk-through of the space and a visual inspection of all surfaces, floor to ceiling. It’s important that this inspection be done when the structure is as empty as possible so that parked cars don’t hide damage. For commercial parking garages, this often means a nighttime evaluation, whereas with a residential garage, daytime works best.
The visual assessment may reveal damaged areas that require a more in-depth evaluation through what is known as “non-destructive testing.” Often the technique used is called “sounding.” This involves using a piece of metal to drag over or tap on an area and listening for a hollow sound that indicates delamination, which is indicative of rebar corrosion within the concrete.
Types of Repairs Performed
There are essentially two levels of concrete repairs. Common repairs include actions like:
- Concrete replacement. This involves cutting or chipping away damaged material until sound concrete is reached, addressing any corroded rebar, and then placing a concrete patch to replace what was removed.
- Traffic coating application. Water is concrete’s biggest enemy. Traffic coating is a flowable material that is applied to concrete as a sealant and creates a thin membrane that keeps water out. Deck coating protects the concrete and its reinforcement, and can greatly extend the service life of the structure.
- Vehicle/pedestrian barrier repairs and retrofitting. These structures, which take many forms including cables, posts, railings, etc., are critical to vehicle and pedestrian safety. Over time, these measures can degrade to the point where they are no longer effective. In some cases, especially with older parking garages, these barriers were never installed.
At times, more advanced, specialized repairs are needed. They include:
- Cathodic protection. This preventative step is used when an ongoing corrosion problem can’t be solved by other means such as a sealant. It involves embedding hockey puck-shaped metal objects into the concrete that will short-circuit the corrosion reaction, or, in extreme cases, running an electrical current through the reinforcement.
- Epoxy injection. This type of repair is used when cracks are considered “structural” and can compromise the integrity of the structure. Epoxy is forced into the cracks and forms a high-strength bond between adjacent sections of concrete.
- Carbon fiber reinforced polymer (CFRP) application. With this technique, carbon fiber is glued to an area of concrete that needs strengthening due to issues like rebar corrosion. It can produce a significant increase in strength and stability. CFRP can also be used to treat other conditions. For example, concrete can sometimes experience internal chemical reactions (alkali-silica reaction is one type) that cause expansive forces that degrade it from the inside out. Wrapping a structure in CFRP can help it resist those forces.
- Post-tensioning tendon repairs. Cables used in post-tensioned structures can corrode over time, and require splicing or even entire tendon replacement. These cables, commonly called tendons, are critical to the structural integrity of the building.
Ongoing Parking Structure Maintenance Considerations
In order to keep issues that have been addressed from recurring — or to prevent problems from occurring in the first place — a maintenance and repair routine should be followed. Building owners must ensure that:
- Snowplows with exposed metal blades are not used on traffic coatings. Blades must have a rubber covering. The same applies to handheld snow shovels or any other snow removal tool.
- Standing water is removed from concrete within 24 hours even if a traffic coating is used.
- Drains and drain lines are unobstructed to ensure they remove water quickly and completely.
- The garage facade is inspected and maintained as well.
- Regular inspections are conducted by an engineer to determine if repairs are needed. This may be part of a capital asset management program or a separate initiative.
- Garages in locations where there is a high salt content in the air are inspected more frequently. High salt content can be due to a coastal climate, salt being used as part of snow/ice management, or high vehicle volumes resulting in salt deposits from exhaust, etc.
What Pie Can Do for You
Pie offers services that cover the full spectrum of parking garage inspection and upkeep, from assisting with the development of a capital asset management program, to conducting walkthroughs, to performing common or advanced repair design and quality assurance during construction. Our forensic building consultants and engineers have extensive experience in helping building owners maximize the value of their investments.