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Reality of Balcony Repairs

The Reality of Balcony Repairs

Article written by Jack Carr, P.E., R.S., LEED AP, Criterium Engineers
Published in Condo Media, July, 2015 

The word balcony gives rise to thoughts of romance (think R & J) or grand views from luxury high-rises but the reality can be different for the building committee or property manager tasked with solving the problem of deteriorating 25+ year old balconies.  Like decks, balconies come in many types and designs but typically they are incorporated inside the footprint of the building or are cantilevered out using the building floor frames as an anchoring point.  Therefore, balconies tend to match the building’s framing materials i.e. wood or concrete.

Wood balconies have similar maintenance problems as wood decks.  Older non-cantilevered wood balconies need to be checked for the proper attachment to the building’s exterior wall.  Nail fasteners are not suitable for connecting the balcony ledger to the building’s structure.  Appropriate screw or bolt fasteners are needed as this is the most common failure point for these types of balconies.

Inspection for rot and other water damage is the next major issue.  This type of visual inspection should include probing the wood for soft spots; unusual stains; or other signs of weakness in the balcony components.  Often when you find a problem in one area, similar problems will be found in the same area of the balcony.   Non-cantilevered balconies often have a water membrane of vinyl or rubber with a drainage plane under the visible floor boards

 It may be wise to have a roofing contractor sample some of these membranes as these areas are as much a roof preventing internal water infiltration as the roof on top of the building.  Also, be wary of any enclosed structural beam supporting the balcony perimeter.  Sometimes engineered wood products such as LVL’s designed for internal use find themselves outside supporting the balcony with the design theory they can be wrapped with a waterproofing material to protect them.  This often does not work and when the waterproofing material allows water infiltration the wrap actually holds the moisture against the wood product thus accelerating the water damage.

Concrete balconies have their own issues but the common denominator is water damage.  Concrete balconies are often cast with the concrete floor framing to form a cantilevered slab jutting out into space.  Over time these concrete slabs form microscopic and then hairline cracks allowing water to penetrate into the inner core of the slab.  Maine’s harsh winters and proximity of high-rise condos to water front locations the water and marine salts can cause corrosion scale to form on the reinforcing steel.  The formation of this rust creates tremendous pressures in the concrete causing the cracks to broaden and the concrete to spall allowing an ever increasing progression of structural damage to the balcony.

Similarly, the attachment points of the balcony’s post and baluster railing system can be compromised by this corrosion action resulting in the balcony railings not being able to resist the 200 pound horizontal loading required for safety in the building codes.  In additions to visible spalling of the concrete surface other signs are new rust-colored water stains or the formation of stalactites from the concrete’s calcium carbonate leaching from the slab’s interior.

When these types of problems are becoming prevalent it may be time for the property manager to suggest a qualified architect or engineer survey the balconies for their structural integrity.  This may require inspections using scaffolding or lift equipment to provide close-up of the status of critical components.  Inspection techniques using mallets to sound for voids or cutting core holes to learn the condition of the concrete through its entire thickness or the state of the reinforcement rods.

Sometimes well-meaning contractors view these problems with the idea of short-term patch repairs or covering the ugly areas with aluminum or other types of cladding to hide the problem.  These solutions can create more long-term problem resulting in an eventually more costly final repair.  Keep in mind if the underlying problem is not addressed no amount of caulking; grout; or coating system will solve the real problem.  With professional advice and common sense, balcony repair projects can proceed to both an economical and safe solution for all to kick back and relax to enjoy the view.

 


 

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