In an ideal world beams wouldn't have holes drilled through them, but very occasionally they are just unavoidable. If the diameter of the hole is small in relation to the size of the beam, then it is normally not a problem. For instance if a 20mm diameter hole has to be drilled through the web of a 200mm deep steel beam, then the reduction in the strength of the beam will be quite small. However, if the hole is 100mm in diameter in a beam of the same size, then it will have a significant effect on the strength of the beam. It is normally possible to justify this type of arrangement, sometimes even without any strengthening work being required around the hole.

Our structural calculations for checking a steel beam with a hole in it includes the design of any necessary stiffening work.

We need the following information to design beams with holes in the web:

architectural layouts or sketch drawings with dimensions, so we can work out all the loadings on the beam

details of the size of the beam

details of the size and position of the hole

details of the type of construction (concrete or timber floors, brick or block walls etc)

if we have designed the beam then we will have all the necessary information for this design check.

Design information

All design work is carried out in accordance with BS5950 (The structural use of steelwork).

The calculations provided will be suitable for Building Regulation approval.