Managing director of RG Scaffolding-Solihull, Ricki Grenfell, is urging all contractors in the construction industry to re-think scaffolding to increase levels of safety, efficiency and cost-effectiveness. He said it was time for contractors to consider new ways of dust suppression and protection from flying debris on demolition jobs. For many years, I’ve never understood why people think it’s a good idea to fasten Scaffolding to a building, then demolish the structure behind the scaffold using a machine.
Scaffolding is useful if it’s used to take a building apart in reverse of how it was constructed, but I’ve never thought that it goes well with big machinery. It’s not even great for stopping dust because the minute you disassemble it, the dust goes everywhere. If there’s a structural collapse, you’re in real trouble as the recent incidents show. Our modular frame system took six months to design and can be transported in sections and bolted together in a day. The mats hang off a crane or a demolition rig – they’re six metres wide, 15 metres high and act as shield to stop debris and dust. Only a few companies use it and as far as I know, we’re the only one which uses an incorporated jet system to spray water back on to the work face.
Both systems are very unusual but they work brilliantly – as long as used they’re used within the right application and well within an exclusion zone – and we’ll be using them on several jobs over the next few months. Of course, embracing new technology requires investment, but the fact is that many contractors are set in their ways and afraid either of costs or of change.
These are the simple things to do and the benefits are widespread for the client, the public and for demolition staff. Without Scaffolding you don’t need people working at heights, which as we all know is the biggest cause of serious injury throughout the construction industry. However, Scaffolding also gives the public a false sense of security, making people walk right next to a building being demolished rather than giving it a suitably wide berth.
Here let us emphasise, we are not saying there is no place for scaffolding in demolition. There are occasions – mainly during floor-by-floor, very controlled, small-scale demolition – when it is the most appropriate method of dust suppression and protection against debris.
Demolitions Gone Wrong
Ever since the airing of Channel 5 Documentary “When Demolitions go Wrong” which focused on the impacts of several incidents, but not the underlying causes. Us at RG Scaffolding in Solihull, near Birmingham decided to go through all the errors that happen on a Construction site.
HSE looks at the learning points from incidents that have occurred during demolition and significant refurbishment and has collected a number of case studies that cover a range of health, safety and commercial incidents, some of which resulted in death or serious injury and others which could easily have led to single or multiple casualties. In all cases, even where there were no casualties, additional commercial costs often exceeded any potential saving resulting from shortcuts.
Insufficient pre-demolition information
A contract to demolish the high-rise residential blocks built of large precast panels used a ground based high reach demolition machine. A client who provides little to none information on the building structure to the contractor such as, structural connection between the panels will be poorly designed, poorly built and had deteriorated further during the life of the building. Lack of adequate information (and lack of adequate survey or assessment prior to work starting) led to a premature collapse of multiple floors across several bays during demolition works.
Fortunately, because the high reach machine was large enough, as was the exclusion zone, there were no injuries. However, the project was substantially delayed while the incident was investigated, and remedial action taken. This type of building often needs panel connections to be stiffened and floors propped to a formal design prior to demolition.
What happens if the Scaffold collapses?
A large sheeted scaffolding screen can access platforms designed and erected to encase a building, however, the sheeting that prevents dust and debris becomes damaged or wasn’t fitted properly, it could fall into surrounding public areas while the building is being demolished floor by floor.
Fortunately, the local fire service has been called about to reports of the scaffold moving and had been able to evacuate the area so there were no casualties. Demolition work should have been halted at the right stage until the scaffold contractor had attended to reduce the height of the scaffold.
A Contractor can create openings in internal walls to prepare design, but then store the bricks on a suspended timber floor for reuse. The floor may become overloaded and could collapse injuring several contractors and works. I some instances, materials can be stored close to point of use in order to minimise manual handling. In other situations, this can be an overload to the structure and a temporary engineer would have to be advised on how much load the floor could take and how to place load to minimise the risk.