If possible, the scaffold should be dismantled for any extreme weather events, and stacked on the ground, with the platforms securely tied down. Unfortunately, it is not always possible or practical to dismantle your scaffold or there is insufficient notice to achieve this task.
There are several factors that impact on scaffold that is erected during extreme weather events including Snow, Hail, Rain & Wind.
There are not many regions of Australia that are susceptible to having snow fall upon an erected scaffold, but as our colleagues in the UK will readily attest, the effect of a load of snow on a scaffold can be significant. There are many variations that can alter the weight of fallen snow on a scaffold, but as an example, 10cm of snow on a 2.5 metre long platform could weigh anywhere between 23 & 50Kg when freshly fallen. As it compacts and more is added, that can increase significantly, where a heavily compacted layer of just 10cm could weigh as much as 250Kg on a 2.5 metre platform. The weight is not the only factor, compacted snow becomes like ice on the platform and ladder surfaces. Extreme care should be taken and if your scaffold gets covered with snow, it should be swept or shovelled off and a complete inspection of the scaffold should be undertaken before allowing work to recommence.
Hail is a regular visitor to many regions of Australia, and can arrive in sizes that threaten the finish of cars or even the limits of concrete roof tiles. It is very rare for hail to be of sufficient size to worry the integrity of scaffold components, nevertheless if you suspect that a large piece of ice may have impacted on a component, carefully inspect for any alteration in the surface of the component, such as buckling or dents and also carefully inspect any adjacent welds for cracking. The sheltered nature of some of the platforms may provide an environment where hail may rest without melting for long periods presenting a slippery hazard. Hail will eventually melt, and the water may make your platforms or ladders slippery, particularly where spills or wear may have altered the surface.
Care should be taken after any such event, and a complete inspection of the scaffold should be completed before allowing work to recommence.
Scaffold is by nature intended to allow rain to flow off the edges of platforms, and not present a large enough flat surface for the pooling of water. The exception to this is where a scaffold is encapsulated, and then most operators will have created a sloping roof on the encapsulated sections to ensure water runs off quickly without creating any standing water hazard. Care should be taken on any scaffold that has been in the rain, as components may be slippery. It is unlikely that rain would have altered the condition of a scaffold or the integrity of the build, no matter how torrential.
As evidenced by several recent incidents overseas, scaffold is susceptible to wind damage when there is encapsulation or cloth screening attached that forms a solid sail area for the wind to impart force. Encapsulation is usually attached to the scaffold using rubberised straps that will break in the case of heavy wind. Most scaffolds that are hoarded or screened have been erected by professionals and will be tied to a wall structure or braced sufficiently to withstand most wind events.
Where a scaffold is standalone (not attached or associated with an existing building) then the scaffold should be weighed down sufficiently to prevent the sail effect of signs or banners from toppling or lifting the scaffold. Two examples are shown in the pictures, one is a build for a temporary restaurant in Pyrmont NSW, and the other is a sign for a winery in country Victoria. Each had over two tonnes of counterweight to provide stability.
If you have a scaffold, or are hiring a scaffold, please ensure that you take into account the effect of any signs or banners that you intend to place. As we have seen above, signs can create a sail effect and banners also present a significant wind catching area that can impart large forces to the top of a scaffold. If you are unsure, make sure you advise your scaffold company that you intend to place banners on your scaffold, and they will quote you for extra bracing to prevent any mishaps. A single 3 metre banner can impart a force equivalent to two men pushing on the side of a tower. More banners placed high on the scaffold can create a dangerous tipping risk.
Use & Inspection of scaffold
If there is a weather event in your vicinity, it is best that you not try and continue use of your scaffold during the event unless absolutely necessary. Once the event has concluded, it is always good practice to inspect your scaffold for any changes or movements that may have been caused by the event. Care is to be taken with wet and slippery surfaces, particularly on ladders and stairs. A professionally erected scaffold is a sturdy and safe environment when completed and should endure most weather events without altering that condition. If you are unsure, Safety First! Contact your provider and get the scaffold inspected.