Steel will have an increasing role to play in house construction as the demand for speed and reduced defects shifts the mood towards the adoption of framing systems, argues Michael Martin
Light steel frame is now beginning to play a major part in new construction and I believe is seen as a major framing solution alongside timber frame.
Steel provides a very accurate form of construction and an average house can be erected to achieve a dry working environment within three days. In the autumn of 2000, and in severe weather conditions, I project managed the erection of eight threestorey town houses in six weeks as part of a major phase of steel-framed houses and apartments. Because of its accuracy, the fitting-out trades were pre-determined in terms of materials and installation procedures, thus having a major impact on the build programme, saving 10 weeks and reducing waste materials by 60 per cent.
Steel is a very stable material and suffers virtually no determinable differential movement. This ensures there is no future movement within the structure and, coupled with not needing a drying out period, makes the achievement of zero defects really possible.
Most housing designs are based on traditional construction methods, so when actual construction takes place inaccuracies can be overcome within the blockwork/brickwork and, equally, the internal trades can overcome similar discrepancies in construction.
These factors alone create site-control problems and lead to delays and waste of time and materials.
There is therefore a need to bring together the architect and the steel-frame designer to achieve a house design that takes full benefit of the accuracy advantages that steel can provide. I have found a continuing resistance to innovation, but some architects are now looking to adopt steel frame as a construction method.
A number of developments have been built by major housebuilders in steel frame during the past three years and the benefits of constructing in light steel frame have been demonstrated particularly in poor weather conditions. The recent phase on a Crest site, where building in traditional method would have lost 10 weeks' production, only suffered a loss of three days using light steel frame.
Also, unlike timber frame, the steel was unaffected by severe rain, thus ensuring that internal trades were not delayed. Furthermore, the speed of erection and the ability to construct the roof at ground level before lifting the total roof into position provided far improved working conditions for subcontractors as well as improving safety.
The steel frame designs currently available allow the external walls of the home to provide the total structure without internal structural walls, the joist systems capable of spanning some 6.5m. This 'open plan' concept provides the housebuilder with the opportunity for numerous internal configurations within the same external parameters, thus providing the potential for reduction of specific 'house types' and, possibly, offers the house-buyer the opportunity of alternative internal layouts.
It is well known within housebuilding that local skilled trades are becoming progressively more difficult to find both in terms of ability and in terms of realistic costing. Thus to achieve the production levels demanded of the housebuilder, factory production is being regarded as a major provider of construction - to date most activity has been directed at timber frame and timber panel systems. However, one only has to look at housebuilding in the US, Japan, Australia and New Zealand to note the trend from timber to steel, much due to the availability of seasoned timber. The introduction of steel frame has thus provided an alternative in countries where frame construction has always been the primary construction method, unlike the UK which is predominantly traditional.
The proposed changes in Parts E and L of the Building Regulations will have an impact on materials, and certainly the recent consultation paper generated concern from product manufacturers that the changes to U values proposed for Part L, energy efficiency, would be somewhat impractical. The configuration of steel frame systems can meet such criteria now and thus will provide a meaningful construction method for most housing requirements without affecting the internal footprint and external finishes.
The controls that can be exercised on site using a steel frame system and associated factory manufacture such as electric loom systems, push-fit plumbing, bathroom and kitchen pods, allow site management the opportunity to operate a more efficient and tidy site. This in turn helps to promote the professionalism and sales presentation that are often sadly lacking on construction sites.
Steel frame is now a serious contender as a modern construction method and, alongside timber frame, we shall see a considerable increase in the use of framing systems and greater acceptability by traditional housebuilders. Certainly, the homebuyer and lenders show no resistance to light steel frame and modern construction methods.
Michael Martin established Speedframe in 1995 and has been working with the SCI and the Light Steel Framing Group to expand the awareness and acceptability of steel-frame housing alongside other frame suppliers such as Surebuild and Ayrshire.