Universal beams (UB) 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, see tapered flanged beams (TFB) for more detail on those.
Universal beams are the most common type of steel beam type in roof construction. Typically they are used in conjunction with timber in most roofs, providing additional strength as required. However, many modern homes or buildings with flat roofs rely solely of steel universal beams or their counterparts for support with steel purlins running above or between them.
ROLLED STEEL JOIST (RSJ)
Rolled steel joist (RSJ) was the traditional name widely used in the past for universal beams. The name is still widely used overseas in some countries, but it has become less common now in Australia to refer to them as RSJs.
‘I’ OR ‘H’ Beams
Universal beams are also often colloquially referred to as I beams or H beams due to their appearance being similar to the capital letter ‘I’ when the bottom and top lines are included, or as a capital letter H on its side.
ROOF BEAM SPAN CHART*
The table below shows universal 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|
*Consult your engineer where construction is 2 storey or if there is greater than normal load over an opening.
UNIVERSAL BEAM DIMENSIONS
The following are table provides the physical dimensions for the range of universal beams.
|BEAM SIZE||WEIGHT||HEIGHT||WIDTH||FLANGE THICKNESS||WEB THICKNESS||FLANGE DEPTH||INTERNAL DEPTH|