Steel framing offers many advantages, including less waste and pre-fabricated materials that minimize cutting and measuring in the field. Unlike wood, steel framing won't rot, twist, or warp, and is naturally resistant to fire and pests. These qualities result in a much stronger and more durable structure that is likely to outlast one built from wood. The added strength of the steel frame also allows us to construct larger, taller, and more elaborate buildings. Steel construction also results in near perfect walls, with fewer of the flaws and waves commonly associated with wood framing.
PRO: WET ROT, DRY ROT AND WOODWORM PROOF
With timber accounting for up to 70% of the fabric of a house, rot and woodworm are one of the major causes of timber decay in modern buildings. The two most common types of wood rot include wet rot and dry rot, which are caused by fungal decay in building timbers. Woodworm can be a very common problem with woodworm treatments common within the summer months. Both can cause significant damage to the timber structures within a property. Depending on the level of decay and infestation, it can result with timbers of a property losing their structural integrity.
On the other hand steel is impervious to these forms of decay.
PRO: COST SAVINGS
During past decades, steel frames have cost much more than timber frames. However today the price is comparable, and a steel frame from Modular Build is usually cheaper than a comparable timber frame.
Given that there is little or no difference in the cost of the initial investment, consider the following on going costs associated with timber frames that you may be able to avoid by using a steel frame in your house:
• Rot/woodworm inspection and treatments.
• Rectification of serious wet/dry rot decay and/or woodworm infestation.
• Structural maintenance due to timber frames shrinking, warping, bowing or sagging over time.
• As houses with timber frames are more likely to be damaged by pests, storms, fire and flooding, home insurance premiums are normally higher for houses with timber frames.
PRO: FIRE SAFETY
A timber house frame can easily be destroyed in a fire, however only in extreme situations will a steel frame be damaged in a fire. In the event of a fire, your family is much safer in a steel frame house than a timber house. There are 3 reasons why this is so:
1. How the fire starts
Fires are often started by electrical faults within wall cavities or ceilings. In a timber framed house, an electrical fault can ignite a timber stud or truss and then spread rapidly to the rest of the house. This same electrical fault would be unable to ignite a steel frame or truss, therefore denying the fire this opportunity to start.
2. How the fire is fuelled
Steel does not burn. Unlike a timber frame, a steel frame does not become fuel for the fire to burn.
3. How most fatalities are caused
75% of fire related fatalities are not from the fire itself, but rather from smoke and asphyxiating gasses that are breathed in by those in the house. A steel frame will not contribute to such gasses. While burning timber will release smoke and toxic gasses into the air, steel does not release smoke and toxic gasses as it heats.
PRO: BUILT TO LAST!
Steel frames are straight and true, which means walls, ceilings and roofs do not have ripples or bumps. Because steel has consistent material strength and complies with strict quality controls and tolerances, every steel stud is a good stud.
Unlike timber framing, steel does not warp or expand. Steel framed roofs do not sag over time. Because steel does not shrink, warp or twist, steel framed homes avoid settling problems, such as popping nails, sticking doors and window jambs. All of this means that 50 years in the future, your house frame will be as structurally sound and straight as the day it was built. Steel framing is the only framing material for which any kind of structural durability warranty is offered! Doesn’t that say it all! A common problem in timber houses is frame movement, which results in the cracking of plasterboard. Being a water-based cellulose product, timber shrinks and expands according to environmental conditions. It does so at a rate that conflicts with plasterboard, causing the lining surface and cornices to crack. However steel has minimal expansion, making it very unlikely to cause cracking of cornices and ceilings.
PRO: FLOOD RESISTANT
If you live in area where storms or floods are common, then steel is the obvious choice for you. Steel frames are better equipped to deal with water damage and floods since steel does not rot, does not warp, is highly resistant to fungus and needs no drying time before house repairs can commence.
Steel frames are able to withstand level 9 earthquakes and wind speeds of more than 280 km per hour.
OTHER PROS INCLUDE...
The steel used in house frames is 100% recyclable. Timber however does not get recycled and new trees take a long time to grow! This is also one reason why steel frames have become more economical over the years.
The healthy alternative
Steel frames require no additional chemical treatments, and no spraying of pesticides. Therefore steel is recognised internationally as a better option for people suffering from asthma or allergic reactions to chemicals.
Innovative design options
The strength and lightweight of steel make more innovative design and layout ideas possible. Design aspects such as large open plan layouts that don't require loadbearing walls, very high ceilings, curved walls and circular/curved windows, are all possible with steel framed houses.
Steel framing is also ideal for homes that will be built on unusual blocks of land, including sloping sites.
CON: LIMITED TRADESMEN
Working with steel frames requires a different approach and different tools than working with timber. At the present time, builders and trades who have experience erecting steel frames are rarer to come by than those with timber frame experience. As such, builders may be hesitant to offer steel frames, or resort to reciting some of the myths below to deter homeowners from requesting steel frames.
MYTH: STEEL COSTS MORE THAN TIMBER
In years gone by, steel frames have indeed cost more than timber frames. However in today’s market the price is comparable. In fact, a steel frame from Modular Build is usually cheaper than an equivalent treated timber frame. Not to mention the on going savings you’ll experience, as demonstrated earlier on in this document.
MYTH: STEEL FRAMES MAKE CREAKING NOISES
This is a popular myth! The truth is that steel frames are not any noisier than timber frames. Studies conducted found that “most occupants of homes with steel frames either reported no sound emitted from the frame or said that, if it did, it was no problem”. In fact, some volunteered additional information by saying that their steel frame was less noise than previous timber framed houses they had lived in.
MYTH: STEEL FRAME HOUSES ARE LESS ENERGY EFFICIENT
This myth results from what is referred to as “thermal bridging”, also called a “cold bridge” or “heat bridge”. This is where the heat or cold within the house leaks outside through a conductive path that is connected to the outer cladding or roofing. The end result is that more energy is required to keep the house cold (in a hot climate) or warm (in a cold climate) through heaters or air conditioning.
Thermal bridging occurs naturally in every house through windows, skylights, vents, doors and even the concrete slab itself. Any material that can conduct temperature and is exposed to the external of the house can be a thermal bridge, leaking the inside temperature. Because steel is a material that conducts temperature, a steel frame could also become a thermal bridge.
This would be a real concern, except that the Building Control requires that a “thermal break” be installed whenever a steel frame directly connects with the external cladding. The purpose of the thermal break is to ensure that the thermal performance of the metal frame is comparable to that of a similarly clad timber framed wall. Thermatape is one type of “thermal break” material which can easily adhere to the steel frames prior to the installation of cladding.
MYTH: STEEL EXPANSION CAUSES CRACKS
False. The truth is, steel framing expands and contracts at rates similar to those of other building materials, such as cornices and plasterboard. Which means it is highly unlikely there will be cornice cracking problems due to frame movement. Expansion induced cracking is more likely to occur with a timber frame because it is a water-based cellulose product, and therefore it expands and contracts according to environmental conditions. Timber moves at a rate that directly conflicts with plasterboard, causing the lining surface to crack, the peaking of ceiling joints and cracked cornices. However steel has minimal expansion, making it very unlikely to cause cracking of cornices and ceiling joints.
MYTH: STEEL INTERFERES WITH MOBILE/TV SIGNALS
False. Electro-magnetic waves and satellite signals can diffract around steel just as easily as timber. Signals and waves pass through the spaces between the studs, allowing the use of all household appliances without any interference. This is just common sense when you think about it. After all, high-rise buildings are packed full of steel. And yet it’s still possible to make a mobile phone call or receive a TV signal from within.
MYTH: STEEL INCREASES THE LIKELIHOOD OF ELECTROCUTION
We smile when we hear this one, as though our building authorities would turn a blind eye to consumers getting electrocuted by their houses. The truth is that steel frames are safe because they are earthed in accordance with Electrical Standards. All new homes are required to be fitted with safety switches, also known as RCD (Residual Current Devices). These switches are designed to prevent death by accidental electrocution, by reducing the possibility of the occupants touching anything live.
A broken or pierced wire in a timber frame can remain live, resulting in the risk of setting the timber frame on fire. Therefore when it comes to safety, steel frame houses are actually safer than timber frame houses.
MYTH: STEEL MAKES WALL MOUNTING DIFFICULT
False. If you’re mounting a photo frame on the wall, the weight of the frame can be held up by the plasterboard. Therefore it doesn’t make a difference what frame sits behind the plasterboard. If you are mounting a shelf and need it to be secured to the frame of the house, you can screw it into the steel frame, rather than using nails as you would in a timber framed house. The approach required is different, but they both require basic tools and a comparable level of skill.
MYTH: STEEL FRAMES CORRODE AND RUST
False. Steel frames have inbuilt corrosion protection. Protective coatings of aluminium alloy or zinc (commonly known as “galvanized iron”) defend the steel against corrosion. These coatings are tough and are of uniform thickness over all the steel, applied to both sides of the steel by the hot-dip process. The coating must meet the requirements of the relevant Authorities Standard, and is therefore monitored strictly under precise manufacturing conditions by the major steel suppliers.
While a timber frame is made up of pieces of varying quality and strength, a steel frame is made from steel of a consistently high quality and strength. In fact, steel framing is the only framing material for which any kind of structural durability warranty is offered.
In external applications (such as roofing) steel is exposed to the elements and has excellent durability, so in less exposed applications (such as inside a wall cavity or ceiling) steel weathers far more slowly.
Where there are cut edges, a naturally occurring phenomenon known as ”sacrificial protection” (or galvanic action) protects the exposed steel edge against corrosion.
The only time that corrosion (over long periods of time) may be an issue is when the frame has been incorrectly installed by the builder, and as a result the frame is in direct contact with a material that is incompatible with steel.
MYTH: STEEL IS NEW AND UNPROVEN
False. Steel frames have been used in housing since the 1940s across the world. It is a thoroughly engineered product. In fact the steel framing industry has a well-earned reputation for being highly innovative. Today’s framing represents the results of decades of research, testing and product improvement. Don’t forget that steel frames are the chosen material for commercial buildings because of their superior attributes.
MYTH: STEEL FRAMES ARE THIN & FLIMSY
It’s true that steel frames are made from thin sheets of steel, however they are structurally stronger than timber. The properties of steel are known and consistent, and conform to NHBC standards. Steel framing components are designed around those properties with an extra allowance included for additional safety. Steel frames use high tensile steel components with appropriate jointing methods, and are engineered to pass strict performance tests.
While a timber frame is made up of timbers of varying quality and strength, a steel frame is made from steel of a consistently high quality and strength. Steel framing is the only framing material for which any kind of structural durability warranty is offered.