Balconies: The Warning Signs of Structural Issues (Part 2 – Metal)

In Part One of this series, we addressed the warning signs of structural damage to concrete balconies.  In Part Two, we take a look at the metal decking on metal/concrete mixed media balconies.  These installations often add a clean, modern look and feel to buildings such as high rise condominiums.  While the combination of concrete and metal materials can be beautiful, they can pose their own structural challenges when not properly maintained.

If any of the indications noted here are present in your building’s balconies, you should bring in a structural engineering professional as soon as possible to investigate.  The engineer will be able to recommend appropriate steps needed to repair the damage and mitigate against further deterioration.  Once repairs are made, they can certify that the balcony is once again sound and able to bear the load of resident activity for many years to come.

Metal/Concrete Balconies – Problem Indicators

  • Corrosion. Corrosion will show up on metal as staining/rusting or bubbling.  When this occurs, it means that water has penetrated the metal and is beginning to eat away at the material.  If unchecked, it can spread to welds and cause them to break apart – putting the entire balcony structure in jeopardy.

    Obvious signs of metal corrosion.
  • Deformation. Over time, stress and environmental extremes can cause metal to deform and ‘bow’. Deformed metal loses its structural integrity, impacting the balcony and any other materials (such as concrete) used in the design.  This is a serious issue that should be addressed as quickly as possible.

    This photo shows metal deformation. It has clearly bowed outward. There is also a distinct separation between the metal support and the concrete of the balcony.
  • Concrete Cracks. Cracks in concrete are a clear indication that stress and/or water have undermined the integrity of the material.  Depending upon the depth of the cracks, the structure may or may not pose a risk to those using the balcony.  In all instances where concrete cracks are visible, immediate evaluation by a structural engineering professional is recommended.

    Here you can see visibly cracked concrete as well as rust and corrosion of the balcony’s metal railing.
  • Metal/Concrete Separation. In a mixed media balcony using both metal and concrete, the two materials should fit together snugly, with no space for water to leak through.  When gaps appear between the metal and the concrete, it can be a sign of serious structural issues impacting areas immediately visible as well as those underlying the structure itself.  A structural engineer will need to look at balconies above and below to see where the structural impact is coming from and to determine how badly the concrete underlayment may be affected.

    This shows a very large separation between the concrete and metal balcony supports.
  • Broken Welds. When it comes to metal balconies, it doesn’t get much more serious than broken welds. These can result from numerous factors including poor filler quality used in the initial weld, too much grinding on the weld which weakens the joint, temperature extremes, and metal corrosion.   A broken weld can cause railings to give way, putting occupants at risk.  If any balcony welds are showing signs of stress or corrosion, you should immediately close off access to the balcony until you can bring in a structural engineer to evaluate the situation.

    A clearly broken weld resulting from a large gap between the metal and concrete.

When maintained properly, metal and concrete balconies are an  asset to high rise buildings and condominiums.  Regular evaluation by a licensed structural engineering professional can help ensure that potential problems are identified and addressed quickly, before they can become major concerns.  In Part Three of this series, we will address structural issues affecting the wooden underlayment of concrete  balconies.

K2N Crest specializes in creative problem solving in the practices of architectural design, structural engineering, architectural engineering, interior renovation, forensic engineering and roof consulting.  Building owners and managers throughout Illinois and contiguous states and Hawaii look to K2N for their architectural, structural and roof evaluation needs.