Member Span

In EC5 the bearing stress at the end of a beam is taken to be uniformly distributed over the bearing area, and for simply supported beams where the bearing area is much greater than is required for strength reasons, the beam need only be designed to span onto sufficient area to ensure that the design bearing strength is not exceeded.

Actual beam bearing length

Beam bearing ā€”5 length required

Beam

Clear span

Effective span (design span) t

Actual beam bearing length iā€” Beam bearing length required

In such instances the design span, i.e. the effective span of the beam, will be the clear span plus half the bearing length at each end, as shown in Figure 4.2. For solid timber beams and joists as well as built-up flooring beams it is usually acceptable to assume an additional length of 50 mm to be added to the clear span, and for built-up beams with spans up to 12 m an allowance of 100 mm should be made. For cases where the beam loading is high or longer span beams are being used, initial checks should be made on the bearing requirement to determine the allowance to be made.

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