Topic: Steel Framing In Christchurch

Steel Framing In Christchurch 

Steel Framing versus Timber
Anyone who has worked on a building site will appreciate the advantages of steel framing against timber.
From the very obvious adverse health factors of working with treated timber to the absolute weight of standing a large external wall.
Steel is lighter and faster to erect and the weather tightness issues disappear which also carries health benefits for the consumer.
N-Steel Framing Solutions is a new company based in Rolleston, Canterbury (just 20 km from ChCh CBD) which manufactures and assembles 90 x 40 x .75mm gauge steel framing.
They have a Frame Master cold forming machine with the technology of FrameCad to support the cutting edge machine.
They can run frames, trusses and roof panels in a very short space of time and quickly assemble them as they come off the machine.
The result.....a lightweight, strong and durable product that comes with a 50 year guarantee.
They also manufacture and sell a variety of sheds for rural and city use which in this material have to be seen to be believed.
At the recent A&P Royal Show hundreds of people visited their stand over the 3 days and the orders are appearing over the desk now as they step up production in all areas.
So why do you still use timber??
Because you haven’t seen the steel framing available at N-Steel Framing Solutions in Rolleston.
Give them a ring now or better still go out and visit the factory and see for yourself.
Remember steel is 100 % recyclable and will not rot or perish. Good for you good for the environment.
0800 58 58 35
www.3N.co.nz

Re: Steel Framing In Christchurch 

Hi N-steel,

I agree about the benefits of steel against timber.
BUT whether you use treated timber or steel it does not change the weathertightness issue.
No matter what you use there must be no water inside the wall as it damages wiring, insulation, and the gib lining. And it creates a health hazard :-(

Re: Steel Framing In Christchurch 

To balance the argument a little more when using steel (high embodied energy) be very careful to detail the construction. Steel framing requires a thermal break from inside to out otherwise there is a lot of thermal bridging and loss of heat in winter and uncontrolled gains in summer.

Re: Steel Framing In Christchurch 

It does change it: with steel you won't get any shrinkage or warping, which means building's dimensions will remain stable over long time, consequently there is no chances for water to get inside if it was properly build in the first place. Cheers :-)

Re: Steel Framing In Christchurch 

to Jeff: you are right Jeff, it is not a secret, steel framing does require thermal break, which has to be supplied with any steel framed structure to comply with building code and we do provide it of course.

Re: Steel Framing In Christchurch 

In the past week I have watched a steel framed double story house being assembled in Porirua, Wellington, Im impressed with the speed of construction. If I was building a new house I would be tempted to use steel for the major hidden framework and wood for exposed features.

Mike

Re: Steel Framing In Christchurch 

Hi.

If you have the alternative between treated timber (>H1.2) and steel, the latter one is probably healthier. Steel can be recycled, treated timber can't. Steel is faster in construction. BUT it needs the same careful detailing for water ingress because YES, steel rotts as well, it's called RUST, even if galvanised over time.
Thermal bridging can be a major problem, especially with the not well considered intra air movement in insulation and ingress of warm interior air into the insulation layer leading to condensation on the steel frame, mainly due to holes cut into your interior lining like pipes, flushboxes and the like. It's absolutely amazing how much wind blows through flushboxes.....
There is one thing about it that is not very well documented but is attracting more and more awareness overseas: EMF.
Electro-Magnetic-Fields. Your electrical installation needs a lot more attention to detail and routing to avoid excessive EMF's.
I found that EMF's are already significantly higher when having a steel roof, even without any cables passing through it. It's the nature of the material.

Cheers,
Ingo

Re: Steel Framing In Christchurch 

hi but steel moves 3 times more in thermal conditions, fails at a lot less in a fire than timber, also steel transmits heat and sound 400 times more than timber, also you have a safety factor of a timber frame being 3 times over the 3604 standard MPA rating than light steel frame structure, timber stores heat and releases it slowly unlike steel, you can acheive a STC rating better with timber, you can stand a timber frame in 3 days, its easier to alter on site, easier for renovations and because it is not as light as steel it does not distort as easy, yes steel is recyclable but at what cost to the environment pumping 4.5 tonnes of carbon into the atmosphere for every tonne of steel unlike trees which eat carbon i dont think steel is every thing people are trying to make it out to be

Re: Steel Framing In Christchurch 

"because it is not as light as steel it does not distort as easy"

WHAT!!! Weight has nothing to do with distortion and in fact can be more of a problem.

Steel is far more stable than wood.

Re: Steel Framing In Christchurch 

is that the only part of the post u could disagree with top effort lol

Re: Steel Framing In Christchurch 

What no further comment? Then let me attempt to answer the rest of ‘annon 4th Sept’ points:

Just because the thermal co-efficient of steel is greater than timber, does not mean it is in some way inferior when used as a structural member – it is easy to design for the difference.

Timber char effect as a fire retarding characteristic, only comes into consideration when comparing a 450 x150 GL beam against a 200 x 100 steel ‘I’ beam (or larger), not when comparing 90 x 40 framing which burns beautifully.

Yes steel transmits heat more than timber but 3 rows of timber nogs also transmit heat and steel does not require any nogs, STC sound ratings are greatly improved by using steel ‘Z’ bridging fixing for Gib. board to studs – timber is a poor substitute.

NZ3604 is a non specific design code with excess redundancy built in which is why a 3x factor is incorporated – steel is more uniform and to specific design not requiring that degree of redundancy.

I can design a 64STC rated floor using either timber or steel – one is not better than the other, only different.

Standing times are comparable and why should you have to alter anything on site if you specified correctly to start with.

If the moisture content of your timber frame exceeds 24% (I have tested frames that are 75%+ in winter), then your distortion by warping, twisting and deflection, are well in excess of steel which is zero - unless you incorrectly overload a steel frame by not spreading your stacks of roof tiles for example.

Finally, I am more than happy to have steel production contribute 4.5 tons of CO2 into the atmosphere so that it can be used in the ‘carbon cycle’ to faster grow my food – tomato growers introduce CO2 at 1000ppmv into their greenhouses for this purpose. If you want to extend that illogical argument, you should simply remove all the CO2 ‘breathing out’ human beings from this planet – problem solved.

Now we should get ‘real’.
Show me a multi-story building over 19m high that uses timber instead of steel (or concrete) for the structure – what you cannot do that? Then you should acknowledge that EVERY material has both strengths and weakness and one is not ‘better’ than the other, only different.

Rex

Re: Steel Framing In Christchurch 

Hi, We are going to build soon in chch, wigram. I am wondering all about EMF and steal framing. Can you please tell me about it? Thank you kind regards

Re: Steel Framing In Christchurch 

Hello, atlantis,

I am not convinced that there is any health risk from the back ground EMF associated with steel framing compared to a timber framing in a residence, acknowledging that the steel frame could but will not necessarily give off very low level EMF.

Every home is filled with low level EMF emitting from every source using electricity. Modern homes with modern appliances usually emit less than older homes with poor wiring and older appliances.

EMF hotspots arise close to all items such as electricity meters main distribution panels, fuse boxes, battery-based back-up power supplies and major wiring ducts. These hotspots generally extend for about 1.2 to 1.5 metres from their source before their EMF radiation fades to background levels.

Hotspots from florescent lights, light switches (particularly dimmer switches), heating panels, intercom base stations and air conditioning units usually have a shorter range.

However, an earth wire for the electrical system must never be connected to metal water pipes or metal framing in a building. There is no problem if no current is flowing through to earth, but if there is a fault in the system a large EMF can be created between the water pipes / steel framing and electric wires in the building.

Typical Magnetic Fields (microteslas) – close to source and 1m away
Electric razor 2000 0.3
Vacuum cleaner 800 2
Television (CTR) 50 0.2
Washing machine 50 0.2
Bedside clock 50 0.02
Refrigerator 2 0.01

So should we stop using an electric razor?
The frequency and period of use is also a factor and I consider it much more important to avoid frequently holding your mobile ‘phone against your ear rather than worry about EMF emissions from a steel frame. However the jury is still out on the long term effects and risks – maybe we might know in another 20 years.

Rex

Re: Steel Framing In Christchurch 

"However, an earth wire for the electrical system must never be connected to metal water pipes or metal framing in a building."

Very good reading from sceptics as always. But all structural steel and piping must be bonded to earth with 4mm copper.

I would rather have a large dose of emf before the breaker trips than have a 230v shock from an appliances fault to earth as I was touching it and a tap at the same time.

Thanks for the great reply to Ecobuilder I was hoping someone like you would put him/she straight.

Re: Steel Framing In Christchurch 

sorry cant work out how to edit my post.
But imagine what would happen if a live wire was touching the metal framing. it wouldn't trip a breaker and the frame would become live, that is until some poor guy is up in the attic and touches some exposed steel work.

Re: Steel Framing In Christchurch 

Hello nzspark,

Thanks for your comments – sometimes I can get my tongue out of my cheek to comment on a more serious note – such as you reminding me of being ‘guttered’ late last year.

Climbing up an aluminium ladder, my head just brushes the galvanised steel gutter and ‘bang’ – I pick myself up off the ground.
What the hell happened? Felt like a 230 volt shock! More cautiously up the ladder again with a tester and yes the roof is ‘alive’. The sun goes behind a cloud and I test again but the roof is no longer ‘alive’.

Confused, I call my fishing buddy electrician and say I won’t take you fishing again until you look over my electrics. He grumbles, comes, and tests everything but can find no fault. I don’t accept that I am going senile (just yet) and so we pull the ceiling out to trace the wiring and find a roofing nail protruding though a purlin, just grazing the live wire making only intermittent contact when the metal roof expands.

He tells me that just about every year he hears of some roofer electrocuted or seriously injured by being blasted off a roof from this cause.
Worth a thought Eh?

Rex