Lintel Beam: Meaning, Types and Purpose

A lintel beam is a common horizontal structure used during construction that you see above the openings for doors, windows, or other similar openings. The purpose of a lintel beam is to hold the above load of the structure. The ends of a lintel beam are built through the wall and are similar in width to that of the wall. 

A lintel beam not only holds the above weight of the building structure but also divides the loads to the adjacent walls to keep a balance. 

Lintel beam: Purpose

1. Lintel beams support the walls above doors, windows, or any form of opening.
2. They can protect the doors and windows by dividing the load to the side walls.
3. Lintel beams can also be used for decorative purposes to enhance the beauty of the structural design.

Lintel Beam: Size

The width of the lintel should match the depth and thickness of the opening, which is somewhere between a range of l/12 and l/8 of the span. Lintel beams have a minimum width of 80 to 100 mm or 3 to 4 inches. 

Lintel Beam: Shape and types

A lintel beam is rectangular in shape. Since their main purpose is to bear a load, they are usually made with steel, concrete, stone, or timber. Out of the three, timber is the cheapest and most easily available. However, concrete is the best choice if you want your structure to be as sturdy as possible and also economical. Steel lintel beams are usually made from pre-galvanised steel, which can be given any shape. Steel has one advantage of being lighter and easy to handle than concrete lintel beams. 

The types of materials used for lintel beams are discussed in detail below.

Concrete lintel beam 

Concrete is the most common choice for construction and has pretty much replaced all the other materials, mostly due to its durability factor. Concrete lintel beams are strong, easy to create and even fire-proof.

For most buildings, the average span is 800mm, while for heavier loads, the thickness of the lintel beams is kept around 8cm, which can both be precast or cast at the site. Main reinforcement bars are employed at the bottom to resist tensile stress, and half of the bars are bent at each end.

Concrete lintel beams are strong and durable. These have fire-resistant properties and are highly adaptable to any size and shape. They are also easily available and economical.

Wooden lintel beam

The earliest types of lintels were made of wood or timber, and they are typically utilised in locations with mountainous terrain where wood is readily available.

Timber lintel beam is less durable compared to concrete or steel, quite expensive, and is not fire-proof. Timber or wooden lintel beams are fixed with steel bolts. 

Wooden lintel beams are constructed by joining two or more wooden pieces depending on the length of the door or window opening. These wooden pieces are kept at a distance by wooden packing pieces or steel plates at the top.

Lintel beams made of wood practically have limited advantages and can only be used in the absence of other durable materials like concrete or steel, especially in hilly areas.

Stone lintel beams

The most significant aspect of the design of a stone lintel beam is its thickness, which is also used to cover brick wall openings in locations where stone is readily available. Because of their excessive weight and the lack of alternative materials available for their construction, they are typically utilised in buildings located in hilly areas.

The stone lintel is offered in the shape of a single piece or many pieces, and as a general rule, the thickness should be at least 8 cm, or 4 cm for every 30 cm of span.

However, stone lintel beams have low tensile strength and should not be used in buildings with a lot of vibratory load. They are also rather difficult and heavy to carry or transport.

Steel lintel beams

Steel lintel beams may be appropriate when there are large opening gaps and substantial superimposed loads. Steel lintel beams consist of rolled steel joists, channel sections (C-sections), or both, either individually or in groups of two or three.

In order for a mortar joint to be constructed at the steel front without cracking, a setback of 3/8″ to 1/2″ from the face of the wall must be given. The lintel needs to be level and plumb in order for the unit that is placed on it to be placed correctly. A steel lintel must also have rust-resistant paint on it.

Steel lintel beams can take a heavier load and are safe from erosion or distortion. They are also easily available and are not labour-intensive.

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