11 May 2008
This has resulted in innovation opportunities which have impacted on the roofer and specialist façade contractor. Peter Hamby, SFS intec’s Pitched Roof Product Manager, reviews how contractors can benefit from recent fastener innovations designed for the new offsite market.
From foundation to roof, demand is increasing for projects to be constructed from pre-engineered structures. In turn, there is a need to ensure the building integrity is protected, as the industry reacts to changing demands.
With offsite manufacture, much of the process of construction is removed from the site to a controlled factory environment. For the roofing contractor this means modular structures are built away from the main site, lifted and moved into place, where they are securely bolted and then overclad and roofed. For this process to be conducted at its optimum level, all manufacturers and contractors need to work together to ensure a good build quality is maintained.
Design and development of advanced fastening and sealant systems have been central to meeting the pressures of offsite manufacture. Innovations have helped achieve improved production efficiency, assured quality and reduced time and costs, whilst complying fully with the Building Regulations.
Fastening technology was originally developed for onsite roofing and cladding for rapid, secure fastening of panels, insulation, frames, membranes and other components. Now it is proving entirely compatible with a wide range of offsite production techniques and new fastener designs are being developed specifically for offsite applications.
Compliance
The new technologies for pre-engineered modular construction are still required to conform to the Building Regulations - and often this type of factory-line production makes compliance easier for installers.
Thermal performance of a building is dependent on the correct installation of each element, and then maintaining the integrity with high quality weather skin installation on site. This is achieved using high performance fasteners and sealants, which fulfil the requirements of (25 year plus) warranties for weather performance and air tightness.
Working within a controlled factory environment allows regular checking and testing to be conducted and easily supervised, before removal of the finished modules to site for finish build. The use of austenitic stainless steel fasteners and purpose designed sealants is crucial in this assembly to ensure a building will comply with current and future Building Regulations, and maintain the energy certificate performance over the 25 or 30 year design life of the building.
Efficiency/quality/accuracy
Achieving high quality build with optimum efficiency remains of the utmost importance for any contract. Pre-engineered assembly offsite, well protected from the ever changing effects of the weather and the demands of a working site, means greater efficiency in use of labour and materials is achieved and quality control procedures policed. This enhances accuracy of construction to very tight tolerances and keeps build costs within closely defined and forecast limits. The use of innovative fasteners and fixing techniques that are faster and more consistently installed are key to achieving the very best build quality on time and budget.
The self-drilling one-shot fastener, now available in a broad range of austenitic stainless steel and head format options, has revolutionised onsite work, and is now widely used to boost efficiency in offsite manufacture.
When fixing insulation and cementitious boards, care must be taken not to overdrive and damage materials whilst, at the same time, keep an eye on speed, costs and productivity.
Employing fastener collation and magazine feeding, using innovative tools, means that each fastener is properly presented to the fixing point in a one-hand operation with no fumbling, dropping or inaccurate fixing. This becomes a true one-shot fixing operation from one side of the work, which doesn’t require nuts to be tightened as with conventional bolts and facilitates a quick, repetitive operation. As all washers are integral and the fasteners are self-centring they deliver much higher precision in fixing. The installation of a one-shot fastener can be achieved at optimum speed offsite, which eliminates the need for onsite fitting, reducing the overall build time, and delivering the ultimate result, a quicker return on investment for the client.
Minimising build time and costs
Construction sites are frequently highly inefficient, in both the use of materials and labour. Offsite manufacture makes it easier to manage project times and the associated costs. For the roofing industry, the discipline involved in having the building assembled on site in good time for the final installation of the weather skin can significantly improve the management of contract costs.
Striving for the future
In a growing sustainability conscious industry, the need to reduce waste and improve efficiencies of resources is high. As we move forward to working more in controlled offsite environments, with specific dimension and time accuracies, further efficiencies and savings can be made through new logistical solutions.
E-technologies and solutions such as core stock control and barcode-generated stock replacement, further aid the pre-engineered factory process. By knowing exact quantity requirements and optimum stock levels, the re-order of the simplest products can be automatically processed, leaving contractors to concentrate on revenue-generating parts of their business. As the construction of modular roof units become more frequent, the design process and the associated systems will be simplified. Using e-solutions to support this process will create benefits throughout the whole supply chain.
Although there will be some challenging times ahead as focus on offsite construction methods grow, the benefits reaped will soon be recognised and obtained. Production line techniques offer a major cost saving benefit, and new fastener technologies will ensure projects keep the same high standards of speed and accuracy which they do onsite.
In addition, by improving the precision of project delivery and timing for a build to be ready for the roofing and cladding contractor, efficiencies can be realised in timing and completion of the onsite weather layer fixing. By reducing the need for installers to be on the roof for long periods of time will also promote safer working conditions. All-in-all, the future of offsite will be a challenge for the roofer and cladder in terms of some adjustment to working practices, but also represents a significant opportunity.