Nick Boulton, chief executive of the Trussed Rafter Association (TRA), discusses health and safety tips for housebuilders when working at height and installing trussed rafters.
Working at height is the biggest risk for housebuilders. Falls from height are one of the most common causes of fatal injuries to construction workers, accounting for 26% of all fatalities according to the HSE.
The HSE says that all work on roofs is potentially highly dangerous, even if a job only takes a few minutes. Therefore, they state that any work undertaken at height must be properly planned, supervised and carried out by competent personnel.
That is why the TRA is working hard with the Home Builders Federation (HBF) and the HSE to improve the information available to the construction industry about the safe practices of working at height when installing roof trusses.
Here is a summary of health and safety tips which housebuilders should consider when working at height and working with trussed rafters, from delivery to installation.
Trussed rafter delivery
Trussed rafters are most often purchased on a supply only basis so prior to delivery, information on the quantity, weights and sizes of the trussed rafters in the roof package will have been provided. This will give the housebuilder and sub-contractors time to finalise their safe working plan for unloading, handling and installing the roof trusses.
It is the housebuilder’s responsibility to ensure that suitable equipment is available to safely unload the roof trusses. In most circumstances, mechanical handling such as a forklift, telehandler or crane is recommended to unload and manoeuvre the trussed rafters. This is because it avoids the need for anyone to access the bed of the lorry, thereby eliminating the potential risk of a fall.
Appropriate storage should always be planned within the site for trussed rafters. This may be at ground and/or roof level and the trusses may be stored horizontally or vertically. Where vertical storage is used then adequate support and restraint must always be provided to prevent trusses falling.
Preparation prior to installation
It is imperative that a full site-specific risk assessment must be carried out before any work commences, and a safe system of work is recorded in the CDM Construction Phase Plan. It is also essential that the installation of trussed rafters is only undertaken by suitably qualified and experienced workers. The housebuilder should ensure these qualities are reflected in their choice of subcontractors or staff installing trussed rafters. Qualifications, such as a Level 2 Diploma in Site Carpentry are particularly relevant.
It is vital that scaffolding has been installed by personnel who have the necessary knowledge and skills to be able to competently install and sign it off, and where appropriate that the scaffold is constructed in accordance with the design drawing to safely support the anticipated loads.
It is important to ensure that there is a safe working platform within the scaffolding structure, and that care is taken to make sure that hop-ups and scaffolding edge protection have been put in place.
Before starting to install the trussed rafters, housebuilders should read the truss layout drawings provided to identify the easiest starting point using the simplest roof of trusses.
Precaution against risks during installation
Before the installation of the roof trusses can begin, it is imperative that the working area has been properly prepared.
As with unloading, mechanical handling during installation of all but the smallest of trussed rafters, such as fink garage trusses, is vital due to their size and unusual shape. Once installation has been completed, trussed rafter roofs are stable, rigid structures capable of resisting the various loads imposed upon them. However, during the initial construction stages trussed rafters have potential to be dynamically unstable building materials. It’s therefore vitally important that measures are put in place to ensure that they do not become unstable and this best achieved by use of the correct temporary bracing. When a suitable base has been achieved with the first group of trusses, this can be more comprehensively braced and provides a stable element from which subsequent work can take place.
Educating the sector on all areas of best practice is part of what drives the TRA. We believe that it is important to share as much health and safety information and safe ways of working as possible. To help reduce the risks of working at height, the TRA has developed a range of information to help housebuilders establish good practice.