Lintel vs Beam, and Chajja (Sunshade) Explained
Lintel vs beam: a lintel is a short horizontal member over a door or window opening. It carries only the wall above that opening and passes it to the wall on either side. A beam is a main structural member that spans between columns or walls and carries slabs, walls and everything above them; it is part of the building’s frame. A chajja (sunshade) is a thin RCC projection, usually cast with the lintel, that sticks out over a window to keep off sun and rain. Because a chajja is a cantilever, its main bars go at the top, not the bottom.
On drawings for Indian houses you will see “lintel level”, “lintel band”, “beam” and “chajja” around every window. They look similar on site, all being horizontal RCC, but they carry very different loads and are reinforced differently. This guide explains each one, how they fit together, and the mistakes that cause cracks above windows.
Last updated: 24 October 2026
Lintel vs beam vs chajja: quick comparison
| Factor | Lintel | Beam | Chajja (sunshade) |
|---|---|---|---|
| Where | Over door and window openings | Between columns or walls, usually under slabs | Projecting outward over windows and doors |
| Carries | Wall directly above the opening | Slabs, walls and loads from above | Its own weight, rain and a small live load |
| Supported by | Wall on both sides (bearing) | Columns or walls | The lintel or wall it projects from (cantilever) |
| Main steel | Bottom | Bottom at mid-span, top over supports | Top |
| Typical span | Opening width plus bearing | Column spacing; often 3–6 m in houses | Projection; commonly about 450–600 mm |
| Part of the main frame? | No | Yes | No |
| Hindi / site name | सरदल (sardal), lintel | बीम, शहतीर (shahtir) | छज्जा (chajja) |
What is a lintel?
A lintel is a horizontal member placed over an opening so the wall above does not collapse into it. Most lintels in Indian houses today are RCC, either cast in place or precast. Stone, steel and brick lintels are also used.
A lintel does not usually carry the whole height of wall above it. Once the masonry is set, it arches over the opening, so the lintel mainly carries a triangle of wall directly above (shown dashed in the diagram), plus any load that falls inside that triangle, such as a slab or beam bearing low on the wall. This is why lintels are fairly shallow members.
- Bearing: the lintel must extend into the wall on both sides. A common rule of thumb is at least 150 mm, or the lintel depth if greater; the drawing gives the exact figure.
- Steel: main bars at the bottom, with stirrups for wider openings.
- Lintel band: in many houses, and in earthquake zones as required by IS 4326 for masonry buildings, the lintels are joined into one continuous RC band around the building at lintel level. It ties the walls together as well as spanning the openings. See load-bearing vs framed structure.
Site language can be confusing: in much of North India, “lintar daalna” means casting the roof slab, not the lintels. See parts of a building for the full set of names.
What is a beam?
A beam is a main structural member that spans between supports, columns in a framed house or walls in a load-bearing one, and carries the slab and any walls above it. Beams are designed for bending and shear along their full span, so they are deeper and more heavily reinforced than lintels. Over continuous supports they need top steel as well as bottom steel. For how beams fit into the frame, see RCC full form and reinforcement and plinth, tie and grade beams.
When a beam is the lintel: in framed houses, a window is often placed so its top meets the bottom of a floor beam. The beam then spans the opening and no separate lintel is needed. A small drop or “dropped lintel” may be cast under the beam to get the right window height.
What is a chajja?
A chajja, or sunshade, is a thin horizontal RCC projection over a window or door. It shades the glass from high summer sun and keeps rain off the window and the wall below. It is usually cast in one piece with the lintel or lintel band.
A chajja is a cantilever: it is held at one end only, so it bends with the top face in tension. That is why its main bars go at the top of the slab and must run back and be anchored into the lintel. Bottom bars alone, a common site mistake, do almost nothing, and the chajja can crack at the root and sag. Like other cantilevers, it behaves as a one-way slab.
- Projection: commonly about 450–600 mm for windows. Deeper chajjas help on south- and west-facing walls in hot regions.
- Thickness: often tapered, thicker at the root than at the tip, as designed.
- Slope and drip: a slight outward slope and a drip groove on the underside near the edge stop water running back to the wall.
- Anchorage: a long or heavy chajja needs enough lintel and wall weight behind it to resist overturning. Very wide projections, or chajjas on openings with little wall above, need specific design.
Common mistakes that cause cracks
- Too little bearing at the ends of the lintel, causing cracks at the window corners.
- Chajja steel at the bottom instead of the top, or top bars not anchored into the lintel.
- Cover blocks missing in thin chajjas, so bars sit at the surface and rust.
- Removing chajja shuttering too early; cantilevers need their props to stay longer.
- No drip groove, leaving damp streaks and peeling paint under every window.
- Cutting a wider opening later without a new lintel designed for the new span.
- Lintels over AAC block walls without proper bearing or mesh at the junction; see AAC blocks vs red bricks.
Hindi terms used on site
A lintel is सरदल (sardal) or simply “lintel”, and the lintel level is “lintel level”. A beam is बीम (beam) or शहतीर (shahtir). The sunshade is छज्जा (chajja). The roof slab is often called लिंटर (lintar), which is not the same as a lintel. Shuttering is “centering” or “shuttering”, and props are बल्ली (balli).
FAQ
What is the difference between a lintel and a beam?
A lintel spans an opening and carries only the wall just above it. A beam is part of the structural frame and carries slabs and walls over its full span between columns or walls.
Is a lintel the same as a lintel band?
A lintel spans one opening. A lintel band is a continuous RC band at lintel level around the building that spans all openings and ties the walls together, which matters in earthquake zones.
Where is the main reinforcement in a chajja?
At the top, because a chajja is a cantilever. The top bars must be anchored back into the lintel or beam.
How much should a chajja project?
Window chajjas commonly project about 450–600 mm, more on sun-facing walls in hot regions. Larger projections need structural design.
Why do cracks appear above windows?
Usually because of short lintel bearing, a missing or undersized lintel, settlement, or a chajja with wrongly placed steel. Diagonal cracks from window corners should be checked by an engineer.
Related guides: Parts of a building · Plinth, tie and grade beams · Load-bearing vs framed structure · One way vs two way slab · All construction guides
Disclaimer: Educational only. Lintel, beam and chajja sizes, bearing, reinforcement and props must follow your structural drawings and IS 456 / IS 4326, as designed by a qualified engineer. Disclaimer
Tanmay Arora, is an Architect with an experience of 13+ years. He is a Management Grad with a post Graduate Diploma in Building Construction and Materials. Tanmay has worked with renowned firms. He has graduated in Bachelor of Architecture. His deep interest in Architecture and Civil Engineering and his experience has made him one of the best architects a client can think of.
