Because balconies often provide an easily accessible outdoor space with a view, they serve as an area for people to congregate. Balcony railings (or “guards”) are used to minimize the possibility of a person (or animal, or object) falling from the walking surface of a balcony to a lower area. Therefore, a railing failure (Figure 1) can result in serious injury or worse, especially as the height of the balcony above the surrounding ground level increases. Among all building features and components, history has shown that failures of balcony railings and similar building components are among the most significant in terms of the consequences for public safety.
Figure 1. Railing failure.
As with many structural and architectural building components, there are several potential causes for balcony railing failures. Some of the most common causes include poor connection to the remainder of the structure or deterioration of the railing materials over time without sufficient repair. Balcony railings must resist imposed lateral loads from balcony occupants leaning on or impacting the railing. If the capacity of the railing connection or of the railing itself is compromised, such imposed loads can lead to a sudden failure.
For wood-framed structures, balcony railings are commonly designed to be connected to the wood framing with screws or lag bolts. If the railing is connected to trim or sheathing instead of directly to the framing (Figure 2), this can have a significant impact on the capacity of the railing.
Figure 2. Connection of balcony railings to trim rather than framing.
Deterioration of the railing members due to wood rot (Figure 3) or corrosion (Figure 4) can also significantly reduce the railing capacity, creating a potentially unsafe condition.
Figure 3. Wood rot deterioration of balcony rail post.
Figure 4. Corrosion failure at a rail post.
While connections may be hidden and deterioration may not be readily visible, detailed evaluation can be helpful in identifying potentially unsafe conditions at balcony railings. Nelson’s team of professionals has evaluated balconies and balcony railings for issues related to design and construction, as well as issues related to deterioration or damage, and has experience in the identification of unsafe conditions at such railing conditions.