Steel has long been used as a favoured building material in the construction industry, both structural steel and cold formed steel (“CFS”).
Steel trusses, which generally support roof structures and coverings, have a number of major advantages over other building materials and come in all sorts of designs and styles according to the actual job.
Before we look at some of the advantages of steel trusses, let’s review some of the types of such trusses.
The design and types of steel trusses are not limited to the ones shown below and there are many more types such as saw-tooth, bowstring, warren, etc. Four well-known steel truss designs are:
The North Light structure has a triangle shape with a long gentle slope and a short slope. This type of truss is called so because of its placement setup, with the log side south facing and the short side north facing;
The Scissor design has two sloping sides with a centre of a large empty ceiling and is generally used in large building such as museums and churches;
The Fink design is mainly used in small buildings such as houses, where the chords of the truss are arranged in easier patterns and with shorter distances;
The Pratt design has multiple vertical chords welded to a single diagonal chord which is attached from the top of one vertical chord to the bottom of another, forming an ‘N’ shape and is commonly used in bridges.
have a high a strength-to-weight ratio making for a stronger product and also roof designs with superior spanning capacities. A steel roof truss can support a lot of weight, and do so over a long amount of space. Accordingly, steel is almost exclusively the primary choice for roof trusses for choice for the design of large sporting arenas, warehouses, airport hangars and so on;
are uniform in product quality and composition as steel is completely true to form. Steel trusses are pre-fabricated in factories with stringent quality control and when arriving on site are constructed exactly as designed, with minute variation – if any;
are incredibly durable and can withstand high stress situations under scenarios of both tension and pressure, as well as requiring very minimal maintenance, provided they are adequately coated. Steel trusses also have high ductility, so significant deformities would have to occur before the roofing system will fail. In reality, a steel truss roof increases life expectancy of the structure often by a factor of 2-3 times when compared to a flat roof solution.
Steel truss roofs can also be designed to resist extreme pressure and high wind uplift ratings, including hurricane-force winds, which makes them an ideal choice for regions which experience heavy snow-loads.
are completely pest resistant as steel has a highly resistant nature which makes it immune to pest infestation, such as termite problems to which, say, timber is susceptible. Accordingly, there are no potentially toxic chemical treatments aren’t needed to maintain the steel trusses;
are fire-resistant having fire-retardant coatings which render steel roof trusses virtually indestructible by fire. Increased fire resistance is an added benefit for structures built in high-storm areas or where there is a greater risk of seismic activity, both of which can increase a structure’s risk of fire;
are eco-friendly as such trusses are fabricated using up to 90% of recycled content and are also 100% recyclable at the end of their lifespan. Combined with the fact that steel trusses are incredibly durable and rarely need to be replaced, this makes them a very eco-friendly building product.
Also, steel and metal buildings score well for being eco-friendly with reputable green building certification programmes such as LEED.
have certain construction advantages in terms of speed and ease they can be erected such as:
- being flat-packed;
- lightweight, making them easier and quicker to transport and install, as well as not requiring cranes;
- requiring no special tools or training to install;
- being pre-assembled off-site;
- easier to install during inclement weather.
have high wind uplift and pressure resistance, that is a safety measure on how secure the building would be in times of a hurricane or other high-wind event. A steel truss roof can be engineered to withstand a very high wind uplift — including hurricane-force winds.
Additionally, because steel trusses have a strong resistance to pressure, they are preferred in areas with heavy snow loads during the winter.
On balance, steel’s uniformity, strength and durability makes it less prone to maintenance throughout its lifetime and its ability to be pre-fabricated leads to faster erection times, resulting in lower overall labour costs.
These and many other advantages make steel roof trusses an affordable building option, especially when the savings gained via lifetime costs as a result of their durability and longevity are taken into account.