Steel is needed everywhere.
If you're pondering building a new house you may be wondering about the materials you should use.
Whilst in some areas you may be limited by zoning laws etc, in others you may be free to choose your building materials. If this is the case you may be able to build using steel.
Steel? Why would you want to do that?
Steel, an alloy composed of between 0.2% and 2.0% carbon, and iron, is now the predominate material for the construction of bridges, buildings, towers and of course, sky scrapers.
Everyone is probably aware that the Empire State Building was built using steel. More and more though, steel is being used to build homes.
Below we examine the reasons why you may consider doing the same:
Steel Buildings Can Be Constructed Quickly
Watch this incredible video of Blue Sky Building Systems putting together the frame work of Rock Reach House over a 5 day period.
As you can see from this time lapse clip, it is constructed by a small team, using very little mechanical equipment. It's like a giant Meccano Set, being pieced together with bolts! Amazing!
Right from the drawing phase onward, steel building can be a very efficient process. Basically, an architect sits at his PC and designs the build. Once the design is finished it can be sent to the factory. Each piece of steel can be molded, welded or cut to the exact dimensions required with little human intervention. The pieces can then be shipped and assembled on site.
This predictability and accuracy speeds up the building process and allows follow-on trades to get to work sooner.
Houses can even be pre assembled in the factory and then just pieced together on site enabling houses to be sold in kit form.
Here are some steel framed home kits available to buy on ebay
Steel is structurally very strong and has great durability.
Steel has the highest strength to weight ratio of any building material, making it an excellent load bearing material. This strength means that wider frame spacing can be used (less joists) meaning less work and more floor space.
Steel will also not shrink, warp or twist.
Steel Prevents Fire Damage
Most deaths come from smoke inhalation when it comes to household fires. Steel doesn't burn so will not add fuel to the fire.
All materials though, weaken with increasing temperature and steel is no exception. Lets take a look at the statistics.
The average house fire burns at around 650°c. The generally acceptable temperature for the beginning of loss in strength for steel is around 300°c. At around 400°c, this loss increases rapidly.
By 550°c the most common forms of steel used in building will retain 60% of structural strength - this is generally accepted to be the failure temperature for structural steel. However in practice this is a very conservative assumption.
Structural steels that are heated above 600°C will lose some of their properties on cooling. The extent of this loss is a function of the grade of steel, with the highest grades suffering most. Tests exist to check if any such loss of properties has taken place.
Fires can also cause distortion and yielding in bolts and connections due to thermal expansion and contraction.
However, in recent years, coatings for steel have been developed to further protect steel structures from the effects of high temperatures providing up to 120 minutes of fire resistance.
An interesting case in point; in Feb 2005 the 32 storey Windsor building in Madrid, Spain, caught fire and burned for two days.
The building was completely engulfed in flames at one point. Several top floors collapsed onto lower ones, yet the building remained standing.
Makes you wonder about the Twin Towers... but that's another story for the conspiracy theorists amongst you :)
So, in a nutshell, steel will likely survive a fire with minor damage. What more can you ask of a building material?
Sometimes referred to as "Mildew", Mold is a fungal growth.
Molds produce allergens irritants, and sometimes, toxic substances.
Inhaling or touching mold spores may cause an allergic reaction such as sneezing or a runny nose, red eyes and skin rash. Molds can also cause asthma attacks.
Mold in buildings can be visible or can be hidden but is generally an indication of a defect. Mold will feed on and weaken any substance that contains carbon atoms (such as organic substances).
Being an inorganic material, steel inhibits the growth of mold, promoting a healthier, more comfortable home environment.
Those (not very) delightful little critters, termites, cause millions of dollars in damage to homes each year.
Termites chew through wood framing and weaken the foundations of your home.
Although termites could perhaps get into your metal framed house they are highly unlikely to be able to bring it down.
Steel is a termite-proof material, which provides security and durability against these destructive pests.
Steel is Better for the Environment and you
An average wood framed home requires at least 40 trees to be cut down. And although a lot of this wood is now taken from renewable forests, a lot isn't.
Believe it or not the framing for an average sized metal framed home can be made from 6 recycled cars!
Steel can also be multicycled endlessly with no detrimental effect on its properties.
During the manufacturing process, steel also produces far less waste than wood, at just 2% versus 15-20% with no addition chemicals needed.
All steel structural elements can be very precisely fabricated to tight tolerances before delivery to site, facilitating rapid and waste-free assembly. From the very beginning.
Before about 1860 steel was an expensive product, made in small quantities and used mostly for swords, tools and cutlery; all large metal structures were made of wrought or cast iron. Since this time, our ability to produce steel has sky rocketed and it's relative worth has gone down substantially.
Steel is now a far more affordable building material. In inflation adjusted terms, steel has fallen in price even since 1980 and is cheaper than it was 15 years ago.
In fact, a steel framed home can cost less than a timber framed home to build. Blue Sky Homes say a home made by them will cost around the same as a traditional house.
As steel production is so efficient it also often means shorter construction times which, in turn, means less labor costs.
There are also very low ongoing maintenance costs with a steel framed house.
Unlike wood, which is a substance very susceptible to the elements and rotting, steel will probably last the length of your mortgage ;)
With a steel frame home, you could be protecting your childrens' (and great great great great grandchildrens!) inheritance.
Once you've bolted a steel house together, that's pretty much it!
Our favorite one!
The versatility of steel gives architects the freedom to achieve their most ambitious visions. The increased strength and ability to create whatever shapes you want from steel means you can have much more innovative design ideas for example,- curved walls or large overhangs etc...
The steel skeleton concept makes for an extremely flexible structure. The only real limit is the imagination of the architects and engineers who design and put the pieces together.
why don't we use Steel for all our houses then?
Typically the construction techniques most commonly associated with building houses are related to a combination of local tradition and economics.
The way houses are built varies considerably from place to place. The fact is though, there are hundreds of thousands of house builders in the U.S. -and globally- who are equipped with the tools and skills for building in wood and not steel.
Finding a builder who has the experience and competence to use steel can be difficult. If your builder is not experienced in using steel, they may try to steer you to a material that they are more comfortable with.
There are also some common misconceptions that perhaps effect an individuals choice away from steel (they might even get these ideas from a builder). Some of these may be:
- That Steel is noisy
- That using Steel causes increased cracked walls etc..
- that using Steel is dangerous in a lightning storm
- That the Steel in your house will rust
- That the Steel will block Cellular Signals
So, lets look at these misconceptions:
Isn't it noisier? Most structures experience some form of movement at the fixing points and this is what is commonly referred to as "creaking" Some steel frame manufacturers actually engineer their steel for silence, eliminating this.
You may also hear complaints of steel roofs being louder, particularly during a rainstorm. Good insulation directly beneath the roof panels, along with good attic insulation and sheetrock can go a long way to deaden this sound.
Cracking?! The cracking that a home can experience is due to a number of things, including the weather and elements. Timber is more liable to shrink and expand depending of the external weather conditions. Steel is not affected by the weather and this therefore removes one of these variables from the mix.
What about Lightning? Your steel framed house is no more likely to be hit by lightning than your neighbors timber framed one. However, when lightning hits a timber frame, the energy from the strike has nowhere to go. Therefore, it explodes and you see a fire start.
Steel, as a conductor of electricity, conducts this energy straight into the ground. For this reason, you will not see a steel framed structure that has the same sort of lightning damage as say, a tree or a structure with a shingle roof.
Rust?! A good steel frame manufacturer will have a coating added to stop this - think sky scrapers (made from steel).
Won't it block my Cellular signal? The straight up answer to this is, yes, it might. However, that's not the end of the story.
Most houses built using steel have a steel frame and actually use other materials for the walls and roof etc... The gaps between the steel will allow your cellular signals through. This means that your signal may be effected less or even unaffected by the steel.
You can also purchase a "booster" or "mobile phone extender" which has an internal and external antenna. This will vastly improve, and in some cases completely eliminate, the problem of poor cellular reception.
Here's an idea - why not use steel for the frame and then add Hempcrete for the walls? just a thought ;)