Beams are used in a building to support loads such as those from upper floors, walls or roofs. They allow for larger openings or spans than would otherwise be possible with joists or rafters.
The most important parameter in beam design is the span of beam which is generally the centreline distance between supports. A small variation in span can have a big effect on its performance. The Australian Standard for residential timber framed construction has published span tables which cover most of the basic timber grades , sizes and loading configurations as do most manufacturers of steel and timber beams.
Generally beams which have a more complex loadings or critical applications should be designed by an engineer.
Steel Beams : Structural steel beams come in the following basic forms
UB – Universal Beam. These have an ‘I’ cross section
PFC – Parallel Flange Channel. These have a ‘C’ section
EA – Equal Angle. An angle with two equal legs at 90 degrees to each other.
UA- Unequal Angle
SHS – Square Hollow Section
RHS – Rectangular Hollow Section
C and Z section purlins
Duragal CA and CC – Angle and channel sections which are already galvanised.
Lite Steel Beam. A cold forming manufacturing process gives LSB a unique profile with a flat, thin web and two hollow flanges. It is made from a single strip of DuoSteel (380/450 grade) using patented simultaneous dual electric resistance welding technology. Manufactured by LiteSteel Technologies, a OneSteel Group Company. For more information refer to www.litesteelbeam.com.au
(Note in 2012 lite steel beams were not generally available on the Australian market, refer to the current manufacturer for details)
Boxspan. Boxspan is a roll formed beam manufactured from two “C” shaped sections of high tensile, zinc coated steel, mechanically locked together with a patented process. For more information refer to www.spantec.com.au
Hardwood – Hardwood beams can be sourced from local sawmills, North Eden Timber ( www.northedentimber.com.au ), Hayes Bega (Old bridge timbers). Hardwood comes in many varieties / species and it is important to choose one which suits your particular application. For instance some species will be more fire retardant than others, some will be more durable and others stronger or stiffer.
LVL – Manufactured high strength , high stability beams eg Hyspan by Carter Holt Harvey, Hyne LVL and Wesbeam.
Manufactured Joists – Hy-Joists, Smartframe, Wesbeam,