Every door and window in a masonry wall needs something to carry the wall above it. In an RCC-framed house, that is usually a cast-in-place RCC lintel, often continuous with a sunshade outside.
Typical Lintel Details
| Item | Common practice in houses |
|---|---|
| Width | Same as the wall |
| Depth | About 150 mm for openings up to about 1.5 m; more for wider openings |
| Bearing | At least 150 mm or the lintel depth on each side |
| Bottom bars | 2 – 3 bars of 10 or 12 mm |
| Top (hanger) bars | 2 bars of 8 or 10 mm |
| Stirrups | 8 mm at about 150 mm spacing |
| Concrete | M20, as for the frame |
Wide openings, openings near columns, and lintels carrying a slab or a heavy wall above need design rather than these typical details.
Lintel or Lintel Band?
A lintel band runs continuously around the building at lintel level, over all openings and through the walls between them. It ties the walls together, distributes loads and improves earthquake resistance in masonry buildings. In RCC-framed houses, lintels may be individual or connected to columns; follow the drawing.
Sunshades (Chajjas)
A sunshade is a cantilever projecting outside the window, usually cast monolithically with the lintel.
| Item | Practice |
|---|---|
| Main steel | At the top of the cantilever, anchored back into the lintel |
| Distribution bars | Across the main bars |
| Thickness | Tapered, e.g. about 100 mm at the wall to 75 mm at the edge |
| Drip | A groove under the outer edge so water drips off |
| Props | Kept longer than for slabs, since there is no support at the edge |
Putting chajja steel at the bottom — a common mistake — leaves the cantilever with almost no tension steel where it needs it.
Checks Before Casting
- Bearing on both sides at least the specified length.
- Bars at the bottom with cover; chajja bars at the top.
- Stirrups in place.
- Formwork level and propped.
- Lintel levels consistent around the room for a neat finish.
The Short Version
Wall-width, about 150 mm deep, 150 mm bearing each side, bars at the bottom — and in the sunshade, steel at the top. Wide openings and lintels carrying heavy loads need the engineer's design.
