THE WEIGHTY ISSUE OF LOADING REQUIREMENTS
Posted on 12th August 2016While the same balustrade system can be suitable for a wide variety of buildings, the detail of the specification must include loading requirements that are tailored to meet the individual building’s needs in terms of both building type and occupancy levels.
Loading requirements are calculated based on maximum occupancy levels rather than average occupancy and locations that are vulnerable to overcrowding require balustrades to withstand higher loadings. Stadiums and sports and performance venues have the most stringent requirements, along with shopping centres, leisure centres and restaurants.
The location of the balustrades within the building and the direction of footfall also have a bearing on the loading requirements. Where a balustrade forms a barrier in a location having an area wider than three metres adjacent to it, this is often termed as being ‘susceptible to overcrowding’. Where footfall will generally travel alongside the balustrade (e.g. in a corridor or walkway), the loading requirements are less demanding as occupants are less likely to congregate against the barrier.
Three calculations must be considered to determine the correct loading requirements for a specific installation, with the most onerous being incorporated into the specification. This is usually the horizontal line load calculated in kN/m (Kilonewtons per linear metre) at a height of 1.1 metre from the ground, as this calculates the strength of the balustrade at its most vulnerable ‘lean height’ location.
To ensure that a balustrade meets the prescribed loading resistance, the balustrade specialist must consider the number of uprights required per metre, the size and diameter of the uprights, the base plate system and the bolts and fixings used. Where the system selected does not have uprights the loading resistance must be accommodated within the thickness of the glass and the strength of the base fixings.
Loading requirements are a complex element of balustrade specification with varying requirements set by British Standards and the Green Guide. As a result, it’s vital to work with a balustrade specialist who will incorporate the architect’s building use and occupancy data into accurate calculations and tailored specification.