Lintel
/ ˈlɪntəl /
Also known as: boot lintel, precast lintel, steel lintel, concrete lintel
Definition
A lintel is a horizontal structural member that spans an opening in a wall - such as a door, window, or archway - and transfers the load of the structure above it to the supporting masonry or piers on either side. Without a correctly specified lintel, the wall above an opening cannot support itself and will crack or collapse.
In practice
Lintels are specified by span, load, and exposure. In modern cavity wall construction, pressed steel lintels (sometimes called boot lintels for their L-shaped profile) are standard - they span both inner and outer leaves simultaneously. Precast concrete lintels are widely used in blockwork and internal walls.
The critical dimension is bearing length - the amount the lintel rests on supporting masonry at each end. A minimum of 150mm bearing is standard, though heavily loaded or long-span lintels may require more. In older buildings, timber, natural stone, or brick arch lintels are common. For openings wider than around 1.8m, or where loads are heavy, an RSJ is often used instead.
Building Regulations
Creating or enlarging an opening in a load-bearing wall is notifiable work under Building Regulations. Approved Document A covers structural adequacy requirements. Lintel manufacturer span tables can be used for standard openings; a structural engineer's calculations are required for wider spans or unusually heavy loads.
Full Building Regulations guidanceSee also