With many places in Queensland copping heavy rain and high winds, businesses with street frontages are reminded to give their premises a once over to ensure they aren’t a safety risk. While they don’t immediately spring to mind during a structural check of the building, remember that faulty awnings can be a serious risk during a storm.
When a storm hits, workers and customers are likely to shelter under awnings to protect themselves from the rain and wind. But as convenient as they are, awnings require care when installing, as well as regular maintenance.
Workplace Health and Safety Queensland has guidance on how to ensure awnings are operating at their best. The guidance was issued as a safety alert after a member of the public was killed when an awning collapsed and swung down towards a shop front.
The awning, constructed in the 1970s, was supported between two cantilevered reinforced concrete beams extending from the building face. The steel framework of the awning was connected to the cantilevered concrete beams by several expansion (torque-setting) anchors. Over time, the expansion anchors had been prised out of the cantilever beams, until the awning collapsed without warning.
There have also been several incidents in Queensland where awnings have collapsed due to anchorage points or structural support systems failing.
The safety alert highlights contributing factors in awning collapses, such as degradation of structural connections (including corrosion that causes the anchor to be prised out of its hole); concealed support connections that cannot be easily inspected; attachment of shade sails that increase the loading; and incorrectly installed insert type anchors (including chemical and expansion) anchors.
Some of the issues identified in relation to insert type anchors include incorrect hole diameter or depth; insufficient anchor embedment; inadequate epoxy for chemical anchors; and dust not removed from holes prior to insertion.
The safety alert focuses on what’s required to make awnings safe – actions by the installers, the principal contractor (initiating a quality assurance system), and designers, who need to include in their considerations the need for structural adequacy for all loads, including wind, temperature and rain.