Benefits of steel frames
| FEATURE | BENEFIT DESCRIPTION | Benefit for | ||
| Specifier | Builder | Homeowner | ||
| Design | High strength-to-weight ratio allows longer spans and less framing (refer page 44 BUILD magazine 117 April/May 2010). | ✓ | ✓ | ✓ |
| NZ Building Code (NZBC) compliance | Steel frame suppliers will provide a PS1 to demonstrate compliance with NZBC Clause B1-Structure. New Zealand Steel supports AXXIS® steel for framing with a 50 year Durability Statement to demonstrate compliance with NZBC Clause B2-Durability. NASH N-11 House Insulation Guide is available as a free download on the PUBLICATIONS page at www.nashnz.org.nz to provide good/better/best solutions for thermal breaks to comply with NZBC E3-Internal Moisture and details to comply with NZBC H1-Energy Efficiency. | ✓ | ✓ | |
| Ease of use | Steel frames are approximately 70% lighter than timber frames making them relatively light-weight and easy to handle. Cladding/linings are screw fixed. Service holes are pre-punched and plastic grommets are supplied to protect pipes and wiring and isolate copper pipes (if used) from the steel frame. | ✓ | ||
| Thermal break | Good/better/best thermal break solutions are outlined in NASH N-11 House Insulation Guide available from the PUBLICATIONS page at www.nashnz.org.nz to provide NZBC compliant solutions for use throughout NZ. | ✓ | ✓ | ✓ |
| Frame stability | Provides straight walls and square corners. Frames remain straight and true saving time straightening frames and providing a high quality finish to wall and ceiling linings. | ✓ | ✓ | ✓ |
| Seismic resistance | Steel framing with brick veneer has been successfully earthquake tested (refer pages 54-55 BUILD magazine 114 Oct/Nov 2009 and video clip at www.nashnz.org.nz). | ✓ | ✓ | ✓ |
| Moisture | Galvanised coating protects against corrosion. Steel does not absorb moisture and will not act as a food source for toxic mould growth. No delays waiting for frames to dry prior to cladding and lining. | ✓ | ✓ | ✓ |
| Fire resistance | Steel is non-combustible. GIB® Fire Rated Systems are available for load bearing and non load bearing steel frame walls and load bearing floor/ceiling systems (www.gib.co.nz). The Steel Construction Institute (SCI) in the UK has recently carried out a fire test on a light steel floor that achieved 90 minutes fire resistance to the BS EN 1365 fire test (refer page 48 BUILD magazine 124 June/July 2011). | ✓ | ✓ | ✓ |
| Sustainability | Can re-use and recycle. Steel is 100% recyclable again and again without losing its properties. Steel framing is manufactured to tolerances of less than 1mm by computer controlled rollformers, minimising waste. Ferrous metal comprised 4% of waste in 2007-08 waste composition survey (www.mfe.govt.nz) down from 6% in 2002-04. By comparison, 11% of waste composition was timber. New Zealand Steel has ISO14001 certification and uses cogeneration from hot waste gases to generate up to 70% of its power requirements. See www.sustainablesteel.co.nz | ✓ | ✓ | ✓ |
| Health and safety | Steel frames are approximately 70% lighter than timber frames so easier to move around on-site. Gloves should be worn when handling steel frames. AXXIS® Steel for framing is a 'Sensitive Choice' product having been independently assessed by the Asthma Foundation's Product Advisory Panel. See http://www.asthmanz.co.nz/building_frames_trusses_and_joists.php | ✓ | ✓ | ✓ |
| History of use | Steel framed houses have been built in NZ since the 1970's and overseas in Australia, UK, USA, Japan and the Middle East. Nowadays steel framing is regularly used for one-off architecturally designed homes and by some of New Zealand's largest group home builders including Golden Homes and Stonewood Homes. Non residential projects include a number of McDonalds restaurants and school projects including Clearview Primary School in Rolleston, built in record time by Mainzeal (refer pages 90-91 BUILD magazine 121 December 2010/January 2011). | ✓ | ✓ | ✓ |
| Availability | Frame suppliers can be geographically searched at http://www.axxis.co.nz/index.php?site=1&pg=finder PlaceMakers also has a steel framing offer. |
✓ | ✓ | |
| Cost | Similar to traditional framing. | ✓ | ✓ | |
| Other | Manufacturers including James Hardie, Winstone Wallboards and Thermakraft provide technical support and details for fixing their products to steel framing. | ✓ | ✓ | |
NZ Steel Durability Statement
