Beam Types


These are a “C” shape and often simply referred to as a “channel” They are not very wide in relation to their height. PFC are generally used in situations where they will be seen such as carports, entry porticos, alfresco areas and canopies. They are sometimes used internally were the beam is to be enclosed in timber also.


These are higher than they are wide and are usually used in a horizontal position. They are also known by their old names such as RSJ (Rolled Steel Joist) and “I” beams. Modern beams have flanges of uniform thickness whereas earlier beams and small beams today have tapered flanges. 100 and 125 beams are still made with tapered flanges.


These are as wide as they are high, for instance a 200 UC is 200mm high and 200mm wide. They are much heavier and more expensive than a UB of comparable height. They are designed to be used in a vertical position however in the housing industry they are often used horizontally to gain maximum strength when there is a height restriction such as supporting a concrete slab were loss of head room is a concern.

Beam Spans

The following are typical beam spans for a single storey tiled roof:

Beam Size                 Maximum Opening
150UB14                                 Up to 4.0m
150UB18                                 Up to 4.5m
180UB18                                 Up to 4.9m
180UB22                                 Up to 5.2m
200UB22                                 Up to 5.5m
200UB25                                 Up to 6.0m
250UB31                                 Up to 7.0m