Types of Lintel

If you are planning to add a doorway or window to a load-bearing wall, you will almost always be required to support the load of the wall above the planned opening with a lintel.

Do You Need a Lintel?

As previously mentioned, you will almost always need to support the wall above the opening you are planning. There are cases (if the opening is very narrow for example) where you will not be required to support the wall. If you are unsure, consult a local builder or building inspector.

Forces on a Lintel

The main forces that your chosen lintel must resist are tension and compression. As the load above pushes down onto the lintel and bending it, the bottom is being stretched and is under tension, whilst the top is being compressed. There is also a shearing force at the point where the lintel meets the supporting bricks, etc. Your choice of lintel type must be based on the amount of these forces.

Wood

Wooden lintels are most often found on older houses (as well as timber framed houses) either in the external wall or hidden behind a stone lintel. Wooden lintels obviously run the risk of suffering from rot, but properly treated can last for a surprisingly long time.

Brick

Not used on their own, brick lintels are usually supported by stone, metal or wooden lintels over external doorways. Most often, a flat steel strip will support the bricks.

Stone

Only suitable for smaller spans, stone lintels are usually found over external doorways of older houses. In most cases where a stone lintel has been used, a secondary wooden lintel will have been used behind it. Stone lintels on their own are poor under tension.

Concrete

Concrete lintels usually have steel rods running the length of the beam to increase their strength under tension. You can buy pre-stressed concrete lintels, which are significantly lighter than standard concrete lintels. This type of concrete lintel is suitable for longer spans than the standard type, where the weight would make them difficult to handle.

Steel

Most modern houses will have been constructed using pressed and galvanised steel lintels due to their strength, flexibility and ease of use. Steel lintels are widely used in both brick built and wooden framed houses, and you can even buy them perforated , ready to be plastered directly on to. Knocking two rooms into one would usually require a heavy duty rolled steel joist due to the length of the span.