Reinforced concrete lintels are now widely used as they are fireproof, durable, strong, economical and easy to construct. RCC lintels can be used for varying spans and load conditions without needing relieving arches. They are preferred over other lintel materials like wood, stone and brick due to disadvantages like decay, difficulty obtaining long stones, and weakness in tension. RCC lintels can be precast or cast-in-situ, with precast used for smaller spans up to 2 meters typically. Depth and reinforcement size depends on the span and load, with larger diameters like 12mm rebar used for spans over 3 meters.

1. LINTELS
1
Presented by
Ar. Krishna Prakash
CEng, AMIE, M.Tech (IIT Kgp),
B.Arch (NIT Jaipur), B.A. (Hons.)

2. LINTELS
A 'Lintel' is a horizontal structural member which is fixed over the
openings, viz., doors, windows recesses, etc. to support the structure
over the openings. Lintels are usually rectangular in shape and they
afford facilities for fixing the door and window frames, wherever they are
used. Lintels may be made of several materials such as wood, stone, brick,
reinforced brickwork, reinforced concrete or rolled steel sections
embedded in cement concrete.
2

3. 3
STONE
LINTEL

4. 4
WOODEN
LINTEL
WOODEN
LINTEL

5. 5

6. 6

7. 7

8. 8

9. 9

10. LINTELS
Reinforced concrete lintels are most widely used these days to span the
openings, because the other materials have become outdated due to the
following drawbacks.
It is observed in connection with materials that the wooden lintels are
liable to decay;
stone lintels are costly and it is also difficult to obtain the stone slabs of
the required length without flaws;
steel sections become loose when exposed to sun due to their high rate
of expansion.
10

11. Though the lintels perform exactly the same function as arches, but they
are preferred to arches due to the following reasons (i.e., Relative merits
of lintels):
▪ The arches require more head-room to span the openings, like doors,
windows, recesses, etc.
▪ The arches require strong abutments (walls) to withstand the arch
thrust.
▪ Lintels are more stable as they support the load by beam action and
transfer the loads vertically to the walls.
▪ The lintels are simpler in construction.
11

12. BEARING OF LINTEL
As a general rule, the bearing of the lintel at its ends should be either 10
cm or 4.0 cm for every 30 cm of span, whichever is greater. For very long
spans, the bearing to the lintel ends should at least be equal to the depth
of the lintel.
NBC Volume 1- Part 6 (Structural Design) - Section 4 (Masonry)
5. Length of bearing of lintel at each end shall not be less than 90mm or
1/10 of the span, whichever is more , and area of bearing shall be
sufficient to ensure that stresses in the masonry do not exceed the
stresses permitted in 5.4 (Annex 4).
12

13. DEPTH OF LINTEL
Further as a rule, the depth of the lintel can be adopted as 1/12th of the
span or 15 cm whichever is greater. The depth can be adjusted to course
heights of brick or stone. The lintels should be strong enough to resist
failure due to the forces of compression, tension and shear.
13

14. TYPES OF LINTELS ▪ Wooden Lintels
▪ Stone Lintels
▪ Brick Lintels
▪ Reinforced Brick Lintels
▪ Steel Lintels
▪ Reinforced Concrete Lintels
14

15. WOODEN LINTELS
15

16. Wooden Lintels
These are the oldest type of lintels and even these days, wooden lintels
are commonly used in hilly areas where timber is cheaply available in
abundance.
In plains, the wooden lintels are rarely used on account of their high cost,
susceptibility to catch fire and liability to decay (if not properly
ventilated) by rot or termites. Wooden lintel cannot be recommended for
fire-proof construction.
16

17. Wooden Lintels
Wooden lintels may either consist of a single piece of timber usually for
small spans or may be of built-up sections of two or more pieces held
together by bolts at suitable intervals. These built-up lintels are generally
used for larger spans. The wooden lintels are placed, with proper bearing
at the ends, to span across the openings and then masonry is constructed
over it.
17

18. Fig 1x. Wooden lintel
18

19. Fig 1 a, b. Wooden lintel
19

20. Wooden Lintels
Where a wooden lintel is required to span
over wider opening (and because of
wooden lintels are comparatively weak),
relieving or discharging arches of brick or
stone are provided over them.
20
Fig 1 c. Relieving arch over wooden lintel

21. Wooden Lintels
The arch relives the lintel of load and
hence the size of the lintel can be
appreciably reduced.
The wooden lintel when decayed can be
replaced without affecting the stability
of the structure.
21
Fig 1 d. Relieving arch over wooden lintel

22. Wooden Lintels
The following points on wooden lintels should be given due
consideration:
(i) Wooden lintels should be made of sound and hard timber, like teak,
rose wood, sal etc. otherwise they are likely to be destroyed by fire and
decay.
(ii) The amount of bearing of lintel ends should be adequate (usually 15
to 20 cm) and the lintel should rest on mortar to have a firm and uniform
support.
(iii) The depth of lintel should be 1 /12th of span, or 8 cm, whichever is
greater. The width of lintel is kept equal to the thickness of the opening.
22

23. 23
Fig 1e. Failure of
Wooden lintel
Fig 1g. Wooden lintel in brick masonry
construction
Fig 1f. Wooden lintel
in stone masonry
construction

24. 24Fig 1h. Wooden lintel

25. Fig 1i. Simonsbath House, Simonsbath, Exmoor Parish, Devon. Wooden lintel over kitchen fireplace
with carved date of 1654
25

26. STONE LINTELS
26

27. Stone Lintels
The use of stone lintels is recommended only in places where stone is
available in abundance and the structure is made of stone masonry. The
stone lintels may also be used in buddings which consist of stone facing.
Stone lintels are constructed of slabs of stones of sufficient length
without flaws either in single piece or combination of more pieces. The
thickness of the stone lintel should be 80 cm, or 4 cm for every 30 cm of
span, whichever is more.
27

28. Stone Lintels
The use of stone lintels in general is not recommended because of the
following reasons:
▪ Stone, being poor in tensile strength, cannot withstand the
transverse stresses. Hence stone lintels should never be used for
opening exceeding 1metre span unless provided with relieving archs
above, otherwise they would require abnormally deep lintel.
▪ It is difficult to obtain the slabs of stones of sufficient length and
depth, free from defects or flaws. Moreover, the stone lintels prove to
be costly as they require good deal of quarrying, transportation to
work site and dressing.
28

29. Fig 2a. Stone lintel
29

30. Fig 2b, 2c. Stone lintel 30

31. 31Fig 2d. Stone lintel

32. 32

33. 33

34. 34

35. 35
Fig 2e. Position and Size of Throating

36. Fig 2f. Stonehenge, an example of Neolithic architecture post and lintel construction
36

37. Fig 2g. Post and lintel construction of the World Heritage Monument site Airavatesvara Temple, India
37

38. Fig 2h, 2i, 2j. Structural lintel over entrance, Treasury of Atreus, Mycenae,Greece
38

39. Fig 2k. Ancient Roman Severan Basilica at Leptis Magna, Libya
39

40. Fig 2l. Architrave in the Basilica di San Salvatore, Spoleto, Italy
40

41. Fig 2l. Stone Lintel 41

42. Fig 2m. Non-structural Mayan ornamental lintel stone, from the Yaxchilan city site in Chiapas,
southern Mexico. (Late Classic period, 600-900 CE).
42

43. Fig 2n. Non-structural decorative lintel at Buddhist Banteay Srei, in Cambodia
43

44. Fig 2o. Non-structural lintel in Buddhist cave temple at Ellora Caves, India
44

45. Fig 2p. Structural lintel over the entry to main Buddhist shrine, Phimai historical park, Thailand
45

46. Fig 2q. Ornamental carved lintel over Mandapa entrance at Chennakesava Temple
46

47. Fig 2r. Door lintel in Bozen-Bolzano from 1632 with Elias Tagger's coat of arms, South Tyrol, Italy
47

48. Fig 2s. Structural lintel with a lauburu and founders' names, above traditional Basque houses in Lower
Navarre, Spain
48
Atalburu (from
Basque atari 'doorway' buru '
head') is the name given to
the lintel above the main
entrance of
traditional Basque houses.

49. 49
Fig 2t. Structural lintel with a lauburu and founders' names, above traditional Basque houses in Lower
Navarre, Spain

50. Fig 2u. Architrave of the left-side portal in the facade of Sant'Ambrogio basilica in Milan, Italy
50

51. BRICK LINTELS
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52. VIDEOS
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53. Brick Lintels
Brick lintels are used to span small openings (less then 1 m ) with light
loading.
Brick lintels generally consists of bricks which are normally laid on end
and occasionally on edge.
Brick lintel is constructed over a temporary wood support (i.e., acting as
centering) known as turning piece. Bricks with frogs (i.e., depressions) are
more suitable for construction of lintels as they form juggles when
bounded and hence possess more shear resistance at the end joints (i.e.,
greater lintel strength). The lintel formed by using frog bricks is termed
as 'joggled brick lintel'.
53

54. The following points regarding brick lintels should be given due
consideration:
(i) Bricks should be hard, well-burnt, free from defects such as lumps, cracks,
flaws etc. and with sharp and square edges.
(ii) The depth of the brick lintels, which varies with the size of opening and
appearance of brickwork, should be multiple of brick courses, viz., usually 10
cm, 20 cm, etc.
(iii) For bonding frog bricks, the cement mortar with mix proportions 1: 3
should be used.
(iv) Brick lintels, being weak in strength, cannot be used for supporting
heavy loads.
(v) Door and window frames should be fixed with a setback of 2.5 cm from
external face of the wall.
54

55. Fig 3. Brick lintels (alternative arrangements)
55

56. REINFORCED BRICK LINTELS
56

57. VIDEOS
● V2-3
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58. Reinforced Brick Lintels
When brick lintels are required to be used over large spans, they are
reinforced with steel bars. These lintels are constructed on the same
principles as R.C.C. lintels, the only difference being good quality bricks
are used instead of concrete. The bricks are so arranged in parallel rows
(either on edge or flat) that a 2 cm to 4 cm wide space is left lengthwise
for inserting the reinforcement, i.e., steel bars or rods. These spaces with
reinforcement are then filled or embedded with rich cement mortar or
cement concrete.
58

59. Fig 4a. Reinforced Brick Lintel
59

60. 60
Fig 4b. Reinforced Brickwork Lintel

61. 61Fig 4c. Reinforced Brick Lintel

62. 62Fig 4d. Reinforced Brick Lintel

63. VIDEOS
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64. STEEL LINTELS
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65. Steel Lintels
These lintels, consisting of rolled steel joists (R.S.J.) embedded in
concrete, are used over large openings, particularly when they have to
support heavy loads of solid walls in position such as shop-fronts, bay
windows, etc. These are sometimes called bressummers.
Sometimes, lintels consisting of steel angles or channel sections in
concrete, are used for small spans and light loading, particularly when
there is no space above to accommodate an arch or for making a relieving
arch. These lintels, being very costly, are restricted in use for special
cases.
65

66. Steel Lintels
These lintels usually consist of built-up sections of three rolled steel
joists or channel sections which are held together at proper distances by
tube separators or cross-bolts.
These steel built-up sections are embedded in concrete to protect them
from the effects of corrosion and fire. At the bottom of steel section, a
strip of metal lathing or wire netting is placed before concreting to
increase the bond or grip between them and the concrete. This whole
system is cured like an R.C.C. Lintel.
66

67. Fig 5. Steel lintel
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68. VIDEOS
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PDF
● 6 Steel cavity lintel

69. REINFORCED CONCRETE LINTELS
69

70. Reinforced Concrete Lintels
In modern time, reinforced cement concrete lintels are extensively used
and practically R.C.C. has replaced all other materials used for united
construction due to the following reasons or advantages.
(i) R.C.C. lintels are fire-proof, durable, strong economical and easy in
construction.
(ii) The relieving arches are eliminated, if R.C.C lintels are used.
(iii) These lintels can be used for varying spans as well as loading
conditions.
(iv) The speed of construction is increased, if precast R.C.C. lintels are
used.
70

71. Reinforced Concrete Lintels
R.C.C. lintels are constructed, usually with a concrete mix having
proportions 1:2:4 (i.e., 1 cement: 2 sand : 4 broken stone aggregate, by
volume), reinforced with mild steel bars.
The plain concrete is unsuitable for lintels as it is comparatively weak in
tension, and hence lintels are strengthened by reinforcement.
R.C.C. Lintels may be either precast or cast in situ. Pre-cast R.C.C. lintels
are preferred for small span (upto 2 m or so).
For larger spans, the lintel should be cast in situ.
71

72. 72

73. Precast Concrete Lintels
Reinforced Concrete Lintels - Reinforced
concrete lintels may be precast in one
piece or in two pieces as a split lintel.
73
Fig 6a. Split Lintel

74. Precast Concrete Lintels
74
Fig 6b. Lintel cum Sunshade

75. 75

76. 76

77. 77
Fig 6b. Concrete lintel (precast, U-shaped)

78. VIDEOS
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79. Reinforced Concrete Lintels
Depth of Lintel
For ordinary load, 15 cm depth is adopted for span upto 1.2 metre. As a
general rule, 2.5 cm is added for every additional 30 cm span.
Reinforcement in Lintel
The number of main bars depends upon the load to be carried from the
wall above and the span of opening. As a rule, for thickness of wall 10 cm
(half-brick), adopt 2 bars and for every additional 10 cm thickness, one
main bar should be added. The diameter of the bar varies with the span
and is adopted as follows, as a general rule (Alternate central bars are
bent-up).
79

80. Reinforced Concrete Lintels
Reinforcement in Lintel
6 mm for spans up to 1 meter.
8 mm for spans 1 to 1.5 meters.
10 mm for spans 1.5 to 2 meters.
12 mm for spans 2.0 to 3.0 meters.
80

81. Fig 6c. R.C.C. lintel details for large spans (>2 meters)
81

82. 82
Fig 6d. R.C.C. lintel detail

83. 83

84. 84

85. 85

86. 86

87. SPECIAL CONSIDERATION FROM
EARTHQUAKE POINT OF VIEW
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88. 88

89. 89

90. 90

91. 91

92. 92

93. 93

94. 94

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96. 96

97. 97

98. 98

99. Recommendation for Bamboo Structures in High Wind/Cyclone
prone areas
B-1 Given below are some recommendations for bamboo structures in high
wind/cyclone prone areas, which are based on Rapid Visual Screening
(RVS) of the damages of past events:
a) …
b) …
……...
h) Highest importance to be given to strengthening the junctions between
structural elements at different levels, that is, foundation, eaves and roof.
Walls be linked together suitably by a continued collar beam at floor, sill,
lintel and roof level.
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100. VIDEOS
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100
PDF
● 11 EQ TIPS 14

101. FROM COST POINT OF VIEW
101

102. 102

103. 103

104. 104
Fig 7e. Usage of bamboo as reinforcement in concrete

105. 105
Fig 7f,g,h. Usage of bamboo as reinforcement
in concrete

106. 106Fig 7i. Usage of bamboo as reinforcement in plinth beam

107. 107Fig 7j. Usage of bamboo as reinforcement in column

108. REFERENCES
▪ S.P. Arora, S.P.Bindra, The text book of Building Construction, Dhanpat Rai Publication
▪ Sushil Kumar, Building Constructipon, Standard Publishers Distributors
▪ P.N. Khanna, Indian Practical Civil Engineer’s Handbook, USB Publishers’ Distributors Pvt. Ltd.
▪ W.B.Mckay, Building Counstruction (volume 1), Pearson
▪ National Building Code of India 2016, Volume 1
▪ IS 1893 (Part 1) : 2002
▪ IS 13828 : 1993
▪ IS 4326 : 1993
▪ https://www.nicee.org/
▪ http://www.bmtpc.org/
▪ Maity, Damodar. (2014). Experimental investigation on chemically treated bamboo reinforced
concrete beams and columns. Construction and Building Materials. 71. 610-617.
108

109. THANK YOU
109
Presented by
Krishna Prakash
Contact no. - 9265516718
krishna2007prakash@gmail.com