DURING MORE THAN 30 years of forensic investigations related to construction litigation, I have observed and repaired a significant number of balcony problems. These issues are less common than roof and window problems, but to put things in perspective, nearly all buildings have roofs and windows and not all buildings have balconies. Given the various modes of balcony failure and performance issues, it is clear that design professionals and contractors must be made aware of better practices for balcony construction. This article shares more than a dozen better practices that are needed to avoid the most common balcony problems.
BACKGROUND Before better practices are discussed, it is important to review historical balcony construction requirements. While adoption of better practices is typically optional, adhering to building code requirements is not. The building code represents the bare minimum standards that need to be followed, regardless of other contract documents that may or may not be available. Until the 2018 edition of the International Building Code (IBC),1 building codes lacked specificity regarding balcony construction standards. Previously, both the International Residential Code (IRC) and the IBC dealt with balconies as a general part of the building enclosure that is required to provide weather protection. Because of the absence of balcony-specific information in the building codes, it was important for contractors to have adequate details provided in the construction documents, such as the project plans and specifications, manufacturer’s instructions, and accepted industry standards, which has been required in Chapter 1 of the IBC since the 2000 edition.2 The 2018 IBC was revised to include a slope requirement for the waterproofing surface installed over moisture-sensitive substrates such as wood framing. This important improvement places the slope requirement at the proper location. Before this requirement was established, it was common for balcony waterproofing to be installed over flat wood framing, with a concrete topping slab specified with minimal slope, typically no more than 1/8 in./ft (10 mm/m). While it is good to slope the finished surface to direct water off of the balcony, concrete is porous, and water will migrate to the waterproofing below. Without slope on the waterproofed surface, the water will be held on top of the waterproofing for an extended period of time. If the waterproofing is nearly all buildings have roofs and windows and not all buildings have balconies. Given the various modes of balcony failure and performance issues, it is clear that design professionals and contractors must be made aware of better practices for balcony construction. This article shares more than a dozen better practices that are needed to avoid the most common balcony problems.
