What are the building advantages and disadvantages of steel and wooden house frames?
Wood is fast and flexible
- Timber provides for flexibility of design, and allows modifications and tweaks to layout during the construction process. Factory pre-fabricated and pre-cut steel frames do not.
- Builders are familiar with using wood, and usually prefer it. Builders report frame construction times of two to two and a half times longer for steel frames.
- Steel frames, however, have the advantage of being able to be constructed in wet weather, and do not require the drying time of wood frames. Wood moves as it dries out.
- Wood is a lower cost raw material than steel.
Snug and sound – Thermal performance
- Wood is 400 times better as a thermal insulator than steel and 14 times better than concrete.
- In solid form, wood also has significant thermal mass properties, retaining heat from the day and releasing it at night.
- Wood also acts as a humidity regulator, absorbing moisture when humid and desorbing moisture when the air is dry.
- Read more about the thermal performance of wood
Wood doesn’t rust
- All building materials used for the structure of houses in New Zealand are required to have a minimum service life of 50 years to comply with the building code.
- Wood, used appropriately in accordance with building standards, will usually far exceed this.
- The mutual enemy of both wood and steel is moisture. Ingress of moisture into wall cavities should be minimised and the design should ensure that any moisture that does enter from leaks or condensation can drain and dry.
- Although steel is normally galvanised to protect it from corrosion, steel frames are susceptible to rust where the surface coating is cut, scratched or penetrated, and from edges that have been cut.
- Wood treated with the appropriate level of preservative, and properly maintained, can last in service for a hundred years or more.