If you are leading a construction business that is framing up the way you’ve always done it - with timber – you may have been hearing a lot in the market about the benefits of cold formed steel (also known as light gauge steel).
Those businesses that have already made the shift to steel framing using offsite and modular construction techniques may have stolen a bit of an advantage and are already realising the difference it can make.
But all is not lost! You may be surprised at how easy it can be to transition to modular offsite construction and light gauge steel (LGS) for framing. For those that make the effort, the benefits are numerous. At the basic level you will find you can start to deliver projects faster, which will help keep customers happy, potentially secure performance bonuses and help you gain more projects.
With efficiency improvements, you will see far less wastage so your costs will be lower. Thanks to improved accuracy, your team will experience minimal re-work requirements or call backs, which adds to project profitability. And with LGS weighing in at less than a third of the timber used for framing, you may find your team are grateful for the change too.
The benefits of steel construction are significant. To get things rolling along, we have put together this comparison so people in the business can make a judgement call on how light steel construction weighs up against timber framing from a builder’s perspective. Note - You can also find a printable leaflet with all of this information here.
Light steel framing is manufactured using “computer numerical control” (CNC) steel roll forming machines that deliver pinpoint precision. This means that all framing components are dimensionally accurate. The result is minimum rework. With more accurate construction methods, you get faster build times.
You will also discover other efficiencies. Offsite panelized framing enables pre-assembled steel packages to be delivered and lifted straight from the truck in sequence. That means greater build efficiency on site too.
Examples of the speed of construction with modular, offsite and light steel framing abound. Click here to see how Acerum where able to build 8 classrooms, 2 laboratories, a cafeteria, offices and bathrooms for Colegio Santa Lousa in less than three months. You can also read about how offsite light steel construction has delivered fast to help the fight against Covid-19 in the UK and US here.
Typical timber wastage is about 20% in the US, based on one study. With light gauge steel, wastage is just 2% - a huge ten-fold reduction, which adds up to considerable cost savings. SCI Studies proved that waste reductions of up to 70% are possible with off-site light steel modular construction.
With less wastage and more efficiency throughout the process, pricing can be sharper, so construction businesses can pass that benefit on to customers as reduced costs or increase their margins as they see fit.
It is not just reduced wastage that is important, it is the environmental impact of what happens to waste. Unlike treated timber for framing, steel is 100% recyclable.
When it comes to factory production, all steel off-cuts are recycled. Steel can be used time and time again, without losing any of its structural integrity or performance properties. Globally the steel industry reports a 66% recycling rate. Even with demolition jobs, 85% of steel is recycled.
Finally, because light gauge steel weighs less than timber, transportation is easier, more efficient and lower cost too.
Timber used in framing construction weighs in at three times more than its thin-guage, high-tensile steel equivalent. Because it is lighter, it is safer and easier to move around on site, and transportation costs less. And of course, with steel, lighter weight does not come at the expense of strength. In fact, cold formed steel offers the highest strength to weight ratio of any framing material. Self-drilling screws and glue are used instead of nails for skirtings, architraves and fixtures. There is no shrinkage and no more popping nails means stronger, more durable connections.
All up, steel framing provides a lighter structure with stronger connections, which means great earthquake and wind load strength that meets even the toughest seismic rating requirements.
Timber and steel in general terms are similarly priced, and while there are many factors to material pricing (volume discounts and design requirements among them), framing cost differentials on a like-by-like basis are in all probability similar.
There is no impact on the cost of building consents either, since consent processes are determined by the cost of the build, not the materials used.
However, there are many pricing advantages to steel over timber that may help secure more profitable projects:
Many people tied in to traditional construction believe it is easy to work with wood and finding trained builders and hammer hands is easy.
However, this is simply an industry myth. Many builders who have worked with timber all their lives find it surprisingly easy to switch to steel framing. What is more, it is now an integral part of every good carpenter's training.
There are no restrictions on the type of cladding that can be used with steel framing and the finished houses look exactly like their timber alternatives.
Indeed, even when architects design in timber, because most steel frames are made to the same dimensions as their timber alternatives, steel can be used instead.
Steel also offers better long term durability on a number of levels, not least of which is lower condensation.
Because steel has high degree of thermal conductivity, thermal bridging is used in construction. This allows steel framing inside the thermal bridging to remain above the temperature that condensation forms in the wall cavity. This protects studs and wall linings.
With timber studs however, condensation is attracted during winter months increasing the moisture content in the building irrespective of the cladding used. This damages the linings and compromises the longer term durability of timber framing.
Timber has a residual water content of 10-18%, so over time there are issues with mold and wood rot, even with treated timber. Unlike timber, however, steel does not absorb water, so it cannot promote mold, making for healthier homes in the long run.
It also means zero issues with the dimensional changes so common with timber framing. Light gauge steel framing stays straight and true, irrespective of age.
Steel's improved fire rating is another advantage of steel construction.
Electrical faults are the most common cause of fires in wall cavities, but cannot ignite steel framing. Steel is non-combustible, so when a fire does burn through wall linings, it will not spread within the framing cavity.
The fire load of a building is a measure of how intensely it would burn if a fire should break out. A higher fire load equals a more destructive fire. Fortunately, steel does not increase the fire loading of a building. However, timber is combustible with at least 20kg/44lbs per square metre of floor area in a typical timber framed house. That is 75% of the total fire load, meaning that a timber house has at least a 1.75 times greater fire load*.
Should a fire break out in a steel framed house, so long as the framing is not visibly distorted, it can be cleaned, left in place and recoated if necessary. It does not need to be replaced.
That all adds up to a pretty reassuring situation for the owners of steel framed buildings, particularly in the more fire-prone regions of the modern world.
Of course, many trust timber simple because people have always built with it… Well, that is true, but older timber houses were constructed with heart timber, and clad in building paper with roof and wall cavities to create space for the timber to breathe.
Most modern timber homes today are built with younger Pinus Radiata, which is less durable. Walls these days tend to be highly insulated too, so airflow is restricted. As a result, cladding and building wraps employed now do no protect against condensation in the same way.
Light gauge steel construction is no new idea. It has been tried and tested for decades now, and has truly stood the test of time. In residential and commercial construction, it has been used successfully for over 60 years.
Steel is more durable than timber. And as we have seen, with steel there is no water absorption and there are no dimensional changes, so it does not cause gypsum board linings and plaster work to buckle or crack.
The trend towards steel has been gathering momentum for many years. Today steel construction accounts for 40% of all building in Hawaii alone. In Japan, over 150,000 steel framed homes are built every year. In Australia, 15% of all new houses are light gauge steel framed, and in South Australia, it is now more than 30%.
All up, steel framed homes are more durable, stronger and faster to build. The advantages are manyfold, and many companies in the construction industry globally are already realizing the benefits. Is it time to put yourself in the frame for light gauge steel?
If you are considering the future for your construction business, steal a commercial advantage. Talk to Howick today.
*Source: National Association of Steel Framed Housing (NASH) https://www.nash.asn.au/nash/
October 2020 #Education