Timber beams may be used as a feature to create character in a new building or to replace existing beams in an older building. They are often used to support floors. The main design issue is to remember that timber is considerably weaker than steel (by a factor of around 30). Therefore there are circumstances where timber is just not a practical option because the beam sizes would be so large that they would not be obtainable.

Generally for large beams, reclaimed timber is a better choice than new 'green' timber. Reclaimed timber is generally stronger and less likely to shrink (providing it has been properly stored). If the timber beams are supporting a floor and they are exposed, then they also need to be designed to provide the necessary degree of fire resistance. This is achieved by allowing for a degree of 'sacrificial' timber.

Our structural calculations for a timber beam includes a fire resistance assessment.

We need the following information to design a timber floor beam:

the span of the beam

the distance between the adjacent supporting walls at right angles to the beam (ie the length of the joists spanning onto the beam)

details of the floor construction, and whether the beam will be exposed

Design information

All design work is carried out in accordance with BS5268 (The structural use of timber).

The calculations provided will be suitable for Building Regulation approval.