Designing for the future.
First, the commercial boys got into it – and now hot rolled steel and light gauge internal partition walls are the norm for light industrial jobs.
Then the steel shed companies arrived, successfully marketing their cold rolled portal sheds, which have sprouted up all over the country – and for good reason.
Now increasing numbers of national home builders are using light gauge cold rolled frames and trusses as an alternative to traditional timber framed homes.
New Zealand Steel is even promoting their Axxis® brand of galvanised steel on TV and this has generated lots of enquiries for steel homes.
Suddenly, steel framed homes are becoming mainstream. Designing homes using steel is the way of the future.
And it’s getting easier to do.
Big manufactures like James Hardy and Winstone Wall Boards have connection details for steel framing on their websites.
GIB® have a bracing calculator especially for steel framing, and they have fire rated systems available for load bearing and non-load bearing steel frame walls and load bearing floor/ceiling systems.
More and more companies are accepting that light gauge steel framing is here to stay and are updating their CAD libraries.
New Zealand Steel is developing a 3D house model where you can click on an area to get the CAD connection detail. Life for a designer using steel can’t get much easier than that! Keep an eye out for it on Masterspec.
In addition, NASH are developing a national standard which, once approved, will mean a Producer Statement (PS1) will no longer be required for most residential buildings. The standard will have generic span tables and connection details that will make specifying light gauge steel easy.
So, as a designer who’s striving for bigger spans, who’s pushing design boundaries but who’s still conscious of client budgets, reconsider steel.
You don’t have to use it for the entire project; why not use it where timber won’t do the job or is too expensive? Use the strength of steel, its longer spans and competitive pricing to your own – and your client’s – advantage.
We can provide a PS1 to demonstrate compliance with NZBC Clause B1 – Structure for our projects. Axxis Steel framing also comes with a 50-year Durability Statement from New Zealand Steel.
Here are a few references that maybe helpful.
- NZ NASH 3405: an Alternative Solution is the current standard referred to by local Building Consent Authorities
- NZ NASH Standard Residential and Low-Rise Steel Framing Part 1: Design Criteria Version 2: October 2010.
- AS/NZS 1170.0 Structural design actions - General principles
- AS/NZS 1170.2 Wind Actions
- NZS 2295 Pliable permeable building underlays
- NZS 3604 Timber framed buildings
- N11 Nash house Insulation guide
- BRANZ BU 454 Avoiding thermal bridging in steel-framed houses
- BRANZ House Insulation Guide
How well does steel framing stand up to earthquake...
Steel framing can be engineered to meet the highest seismic and wind loads prescribed by the NZ Building Code. Steel has the highest strength to weight ratio of any framing materials and a lighter structure with stronger connections results in lower damage from earthquakes. Steel framed houses in Christchurch suffered only superficial but no structural damage. The stronger screwed connections can withstand greater winds including cyclones.
Do homes with steel framing look different?
Yes, they look better. Walls, ceilings and roofs do not have ripples or bumps in them and there are no “nail pops” in the plasterboard linings. Roofs of steel-framed homes do not sag over time, so the finished job keeps looking good. In fact because of the steel’s strength you can design your home with larger open spaces whilst the exterior looks like any normal home.
What about electrical and plumbing service holes?
Our frames are manufactured with pre-punched 34mm holes for running pipes and electrical wiring, reducing preparation time for other trades. Additional service holes are easily drilled or can be punched and we supply plastic grommets to protect wiring and plumbing.