Contents:

**Types of Design Loads for Masonry Lintel**

- Self-weight or a dead load of masonry lintel
- The dead load of the wall above the opening
- Dead load and live load transferred from the roof or the floor supported by the wall over the opening

**Fig.1: Masonry Lintel Over Window Opening in a Masonry Wall**

**Self-Weight or Dead Load of Masonry Lintel**

All solid masonry and concrete lintels must be adequately grouted. The dead load of the lintel can be computed if enough information about the dimension of the lintel is available. For design purposes, initial or preliminary cross-sectional dimensions for the lintel are considered.
Since lintels are an important part of the wall, the lintel's width is the same as the wall, and the only unknown that is required to estimate the self-weight of the lintel is its depth.
Depth of approximately 20 mm per linear of 300 mm of the span can be considered for preliminary design. The computation of masonry self-weight depends on masonry unit types, for example, lightweight, medium weight, or normal weight, and the unit weight of the grout employed for the wall, and it may be taken as 1651.94 Kg/m^{3}or 2242.59 Kg/m

^{3}. As an alternative for the method of dead load calculation mentioned in the above section, the dead load of the lintels that have specific height and breadth which NCMA offers could be utilized, and considerable errors can be avoided. The values provide by the NCMA for a specific size of lintels are provided in Table-1, and the values are based on grout unit weight of 145 pounds per foot

^{3}, normal unit weight of 145, and lightweight of 100.

**Table-1: Lintel Weights in Kg/ 30cm**

**Dead Load of the Wall Above the Lintel**

The dead load masonry above the lintel is the weight of masonry contained in a forty-five-degree triangular area above the lintel if arching action is considered to occur.
Consequently, the dead load for which the masonry lintel must be designed consists of masonry dead load in the triangular area plus self-weight of masonry lintel.
It may be claimed that the degree which made the triangular area above masonry lintel vary from 45 to 60 degrees.
The dead load for the case where the triangle is formed due to 60^{o}over the lintel effective span is greater than a dead load of masonry contained in the triangle created by 45

^{o}over the effective span of the lintel. It is advised to employ the triangular formed by 45

^{o}to calculate wall dead load over the lintel, as illustrated in Figure-2.

**Fig.2: Dead Load of Masonry in case of Arching Action and Masonry Self-Weight**

**Fig.3: No Arching Action**

**Dead load and live load transferred from the roof or the floor supported by the wall over the opening**

Live and dead Loads exerted on masonry lintel by roof or floors could be either concentrated or uniform loads.
Regarding concentrated loads, depending on the results of tests, a method for specifying concentrated load distribution on walls is suggested by NCMA.
As per the tests carried out for concrete block, brick masonry, and ACC masonry, it is assumed that concentrated loads may be dispersed at the slope of 2:1. Figure-4 shows the distribution of concentrated loads on masonry lintel.
**Fig.4: Distributions of Concentrated Loads on Masonry Lintel**

**Read More:**

**Different Types of Lintels and their Uses in Building Construction**

**Types of Openings in Walls, its Parts and Types of Lintels and Arches for Openings**