by Adia Walker / Published November 2014
When the sun is shining, a breeze is blowing, and scenic views are available, who wouldn’t want to spend time outdoors on a balcony? Balconies can be a desirable asset to any community association, but they must be maintained in order to be enjoyed safely. Taking care of the concrete that holds your balconies and railings in place is vital and can be easy if you have a basic understanding of what issues can occur and how to prevent them.
According to Donald Chalaire, PE, from Chalaire and Associates, Inc., concrete deterioration can be defined as cracked and spalled pieces of concrete falling off a building surface. “Concrete is being pushed outward because of expansion of the steel bars due to corrosion,” he says. “The expansion is the result of iron being converted to scaling rust. The scaling rust needs much more space and has enough power to break the concrete.”
If deteriorating concrete is left unchecked, serious safety concerns emerge. “When the deterioration is severe, it can affect the inside of units and can even cause catastrophic failure if not taken care of over a period of time,” says Steve Young, P.E., President of Howard J. Miller P.E., Inc. “Most of the time though, people are aware that it is looking bad and attend to it before the balcony falls off the building,” he says.
Concrete corrosion is caused by rainwater and chlorides getting into concrete down to the level of the steel bars. “Over time, the outer surfaces exposed to weather absorb more and more mild acids and chlorides that penetrate deeper and deeper into the concrete,” Chalaire says.
Different variables affect the time it takes for the contaminants to reach the steel bars. How the water gets into the concrete, how long the cycles of wetness and dryness occur, and the variations of exposure all play a role.For waterfront buildings, this typically occurs every 15–20 years, but can beshortened to just a few years if the concrete is very porous or the steel bars are not embedded deep enough. “The corrosion begins when the contaminants reach the steel bars, and the rust begins to consume them,” says Chalaire.
Terri Chalaire, P.E., from Chalaire and Associates, Inc., explains that cracks in ceilings and floors are common in concrete-framed structures, new or older. “The cracks can be significant and contribute to dangerous conditions and concrete damage, or they can be insignificant, not causing a structural problem or other concern, or they can be somewhere in the middle, possibly allowing water intrusion and problems down the road,” she says. An experienced professional will be able to diagnose the issue based on the shape and size of the crack, the configuration of the steel re-inforcing bar in the slab, the general configuration of the slab, and the location of the crack relative to the balcony configuration. For those without extensive knowledge of concrete, some signs of a serious problem include:
Quality work should not need to be repaired for 10–20 years; however, in any given association, repairs will likely be needed every few years. “Unfortunately, repairs performed at one location do not mean there won’t be problems at other nearby or unrelated locations,” Terri explains. “Brand new concrete at one unit does not mean the 20-year-old concrete at another unit will last forever.” She advises property managers to monitor buildings and make note of any repairs that will need to be completed, then have them all completed at one time. If this process is repeated every few years, it should help to minimize repair projects and costs of projects.
While well intentioned, repairs performed by a handyman or association staff could actually cause bigger problems. If not done properly, the repair could loosen and fall, causing injury or property damage for which the association would be liable.Professionals will have extensive knowledge of the published standards and codes that guide concrete repairs. In fact, two different professionals are often needed to assess and conduct concrete repairs. First, a professional engineer should be contacted to inspect an area and write a proper repair method.
Selecting a professional contractor who holds a General Contractor (GC) license is the next step. “An effective way to achieve comparable bids is to have an engineering survey performed and a specifications and bid package written,” says Terri. “This package can be provided to multiple contractors. An engineering company with a Certificate of Authorization issued by the state can provide these surveys and specifications, which can also be used later to obtain a building permit for the work.”
While there may be some resistance to the idea of removing carpet to inspect balconies, it is absolutely necessary, according to Donald. “I have seen much evidence of the harm carpeting on balconies has caused in Florida, where chloride infusion into concrete is the main cause of deterioration,” he says.
He advises against carpet on exterior balconies because it enhances concrete corrosion and cracking. After a rain shower, the carpeting will remain wet long after other smooth surfaces have dried. In addition, rains can’t flush away salt from carpets as it can from other surfaces.
Another problem that can accelerate deterioration is ponding water due to inadequate slopes or excessive waviness. “All water that hits balcony surfaces should have a path for run off,” says Donald. Water ponding with plenty of sun and wind exposure will eventually dry out, but shaded or hidden areas take longer. Ponding areas covered by tile or pavers almost never dry out, according to Donald.
Young recommends a series of simple steps for proper balcony and railing maintenance.
If covering a balcony with tiles:
Implementing some simple, preventative measures, knowing what to look for, and having a regular inspection/maintenance plan in place will allow residents and guests to safely utilize the balconies in your community.