A significant-sized opening in a masonry wall will always require a lintel of some sort to bridge over it. A lintel is considered to be a secondary structural element whose purpose is to support the masonry that arches over the opening. It does this by spreading the vertical load of the masonry – and any other vertical loads being applied to the wall – away from the opening to either side of it.
This Technical Guidance Note offers advice on the different types of lintel that are available, the detailing requirements of lintels, and the way in which they are designed.