A lintel is a pervasive part of buildings. Whenever we want to create an opening like doors & windows in the building, we use lintel above the opening as a simple solution.
Although lintel construction is simple and it is very commonly used, we are here to describe the theoretical definition of the lintel.
In this article, we have also presented the types of lintel and discuss briefly to give you an idea. Why does this matter? It will help you to select the best kind of lintel for your construction work.
What is Lintel?
A lintel is one type of beam which is utilized to support the above wall or partition material when openings like doors, windows, and so forth are necessary to provide a building structure. The primary function of the lintel is to take loads originating from the high wall and transfer its heap to the side walls.
The lintel beam generally ends in the masonry wall to convey the weight carried by them to the masonry walls, and its width is the same as the wall width. The lintel can likewise be utilized as an enlivening compositional component.
Types of Lintel
While timber is as yet utilized in the development of homes, heavier materials, for example, block, concrete, and stone, can likewise be used, particularly in the event of business structures and private condo squares. Thus, the utilization of stirred steel lintels has developed increasingly well known. Depending on the costing and availability of materials, different materials are used for lintel construction. Lintels are classified into the following types according to the elements of their development:
- Timber lintel
- Stone lintel
- Reinforced concrete lintel
- Brick lintel
- Reinforced brick lintel
- Steel lintel
After seeing these six types of lintel you may ask a simple question.
Which one of these lintels should you use for your construction project?
It's you who should decide the answer. But to help you decide, a brief description of these six types of lintels are discussed below.
Wooden or Timber Lintels are the most seasoned sorts of the lintel. They are fundamentally used in the hilly areas where timbers are accessible. But in open areas, uses of timber are constrained as a result of the significant expense and accessibility of present-day materials. If there should be an occurrence of more great dividers, timber lintel is made out of two wooden pieces avoided as much as possible with the assistance of wooden separation pieces. Sometimes, timber lintels are reinforced by the arrangement of mild steel plates at their top and base; such lintels are called flitched lintels. It has a few other disadvantages-
- It is less durable.
- Timber being combustible it is vulnerable to fire.
- These lintels tend to be structurally weak.
- Without appropriate ventilation, timber is obligated to rot.
Rectangular bits of stone can be utilized as a lintel. This type of lintel is mainly used in this area where the stone is plentifully accessible. On the off chance that the length of the opening is long, by then, in any event, two bits of timber are joined to give the lintel all things considered openings. They are merely used in mountainous buildings as they weigh too much and due to the non-availability of other materials for their construction. Its use is intrinsically bound to stone masonry structures. Stone lintels must be utilized according to an understanding of the characteristic layering. The thickness of the stone lintel is a significant factor for its design. As a thumb rule, the thickness is taken as 4 cm. Per 30cm length of span and the minimum thickness should be 8 cm. This sort of lintel will be firm and solid. There are a few inconveniences also of the stone lintel.
- Its high cost and secondly its inability to withstand excessive transverse stress.
- Due to their weak tensile nature, they are not used in buildings where vibratory loads are subjected to the structure.
- It is difficult to deploy them in cities as its transportation is a very complex task.
Reinforced Concrete Lintel
At present, reinforced concrete lintels are very common in use. In this type, reinforcement is used to overcome the low malleable issue in concrete. They are developed in present-day structures. They are suitable for heavy loads and larger spans. Their thickness is kept around up to 8 centimeters for every meter. RCC lintels can be either precast or cast-in-situ. Generally, precast reinforced cement concrete lintels are used when the lintel span is smaller. Lintel width should be the same as wall width. The depth of the lintel depends on the length of the span and the loading's magnitude.
Concrete, though strong in compression, is fragile to tensile stress, so main reinforcement bars are used at the bottom to resist the tensile stress. Half of these bars are cranked at the ends. Shear stirrups are provided to withstand shear stress. Typically, cement, sand, and aggregates are mixed in 1:2:4 ratio to form cement concrete mortar. This lintel has a handful of advantages:
- They are durable, rigid and strong.
- The reinforced concrete lintel has fire-resisting properties.
- They are economical and easy in construction.
- The main advantage of the RC lintels is adaptability to suit any size and shape.
Brick lintels are constructed with hard, well burnt first-class brick. It can be formed as bricks on end, bricks on edge, and coursed bricks laid horizontally over openings. This type of lintel is used when the opening is small (less than 1m) with light loadings. Their depth varies from 10 cm (thickness of one brick) to 20 cm depending upon the span. Bricks with frogs filled with mortar give more shear resistance at end joints than the standard blocks.
Reinforced Brick Lintels
Heavy loadings and more substantial span length are the problems for brick lintels. These can be overcome by using the reinforcement bars. Reinforced brick lintels thus provide more support than the brick lintels. The depth of the reinforced brick lintels is equal to 10 cm. or multiple of 10 cm (or one brick thickness). The arrangement of the bricks should be such that there is enough space in lengthwise between the adjacent bricks for the insertion of mild steel bars as reinforcement. After insertion bars, the remaining gap is filled with 1:3 cement mortar. 6 mm bars are used as vertical stirrups at every 3rd vertical joint. 8 to 10 mm bars placed at the bottom are used as primary reinforcement.
Steel lintels can be suitable when the superimposed loads are heavy, and the opening gaps are significant. Steel lintels are preferable when the depth of lintel plays an essential role because the designer cannot ignore the depth of reinforced concrete lintels due to heavy loads. These lintels consist of channel sections or rolled steel joists or channel sections either used singly or in the combination of two or three units. Depending upon the requirements, the lintel can be a single section or combinations of two or more. Single steel joist is either embedded in concrete or cladded with stone facing to keep the same width as the wall. Combination of two or more units are placed side by side and held in position by tube separator. Relieving with water is accomplished in any event for ten days. It has many advantages:
- Steel lintels can be utilized to help heavier loads over more prominent separations without the need to change or strengthen.
- Steel lintels are impervious to rust, erosion, or distorting.
- Steel lintels are more practical and less labor-intensive.