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IS 2119:1980 is the Indian Standard (BIS) for construction of brick-cum-concrete composite (madras terrace) floor and roof. Provides guidelines for the construction of traditional Madras terrace floors and roofs, which consist of edge-laid bricks over closely spaced joists, topped with a brick-bat concrete course. The code details material specifications, laying procedures, and curing methods, primarily relevant today for heritage conservation and traditional building practices.
Code of practice for construction of brick-cum-concrete composite (madras terrace) floor and roof
Overview
Status
Current
Usage level
Specialized
Domain
Structural Engineering — Building Construction Practices incl. Painting, Varnishing
EN 1992-1-1:2004European Committee for Standardization (CEN), Europe
MediumCurrent
Eurocode 2: Design of concrete structures — Part 1-1: General rules and rules for buildings
Covers design of concrete slabs with filler blocks (Section 10.9.4), a modern engineered equivalent.
ACI 318-19American Concrete Institute (ACI), USA
MediumCurrent
Building Code Requirements for Structural Concrete and Commentary
Details requirements for one-way and two-way concrete joist (ribbed slab) construction, a similar structural system.
BS 8110-1:1997British Standards Institution (BSI), UK
MediumWithdrawn
Structural use of concrete. Code of practice for design and construction
Contained specific rules for the design of ribbed, waffle, and hollow block slabs, a direct predecessor to Eurocode's rules.
BS 7913:2013British Standards Institution (BSI), UK
LowCurrent
Guide to the conservation of historic buildings
Provides principles for assessing traditional construction forms like jack arch floors, which are conceptually related to Madras Terrace.
Key Differences
≠Material Specification: IS 2119 is based on traditional materials like lime for mortar/concrete and burnt clay bricks, whereas modern equivalents (EN 1992, ACI 318) mandate engineered materials like Portland cement concrete of specified strength classes and manufactured filler blocks.
≠Design Philosophy: IS 2119 is a prescriptive 'code of practice' based on historical precedent and deemed-to-satisfy rules. International standards use performance-based 'Limit State Design' or 'Strength Design' methodologies requiring rigorous structural calculations.
≠Reinforcement: The Madras Terrace system is fundamentally unreinforced or minimally reinforced. Modern standards for ribbed/joist slabs require designed steel reinforcement in both the ribs and topping slab to resist bending, shear, and thermal/shrinkage effects.
≠Integration of Waterproofing: IS 2119 integrates the waterproofing 'terrace' course (graded lime/cement plaster) as a key component of the system. In international practice, the structural slab (per EN 1992) and the waterproofing/roofing system are designed and specified separately under different codes.
Key Similarities
≈Composite Action: Both the IS code and international standards for ribbed slabs rely on the composite action between the topping slab and the supporting joists/ribs to create an efficient load-bearing T-beam section.
≈Weight Reduction: A core principle shared by both systems is the use of lower-density filler elements (bricks in IS 2119, hollow blocks in modern systems) to displace concrete and reduce the overall self-weight of the floor/roof slab.
≈Load Path: The primary structural action in both is typically one-way spanning, where the floor load is transferred from the topping to the joists/ribs, which in turn span between main beams or load-bearing walls.
≈Construction Sequence: The construction methodology is analogous, involving the placement of primary supports (joists), installation of filler units, and in-situ casting of a concrete topping to unify the system.
Parameter Comparison
Parameter
IS Value
International
Source
Primary Filler Material
First class burnt clay bricks or brick tiles.
Purpose-made hollow or solid blocks of concrete or clay; can also be permanent formwork.
EN 1992-1-1
Topping/Structural Slab Material
Lime concrete (1:2:4) or cement concrete (min. M15 grade).
Reinforced concrete, typically minimum strength class C20/25 or higher.
EN 1992-1-1
Minimum Topping Thickness
65 mm to 75 mm for lime concrete; 40 mm for RCC slab over joists.
40 mm, or 1/10 of clear distance between ribs (whichever is greater). Can be 30 mm for non-participating blocks.
EN 1992-1-1
Maximum Rib/Joist Spacing (Clear)
Not explicitly defined, but practice is typically 300 mm to 600 mm based on brick dimensions.
Should not exceed 1500 mm for ribs; 1100 mm for concrete joist construction.
EN 1992-1-1 / ACI 318-19
Design Basis
Prescriptive code of practice based on empirical rules.
Limit State Design (LSD) requiring calculation of ULS (strength) and SLS (deflection, cracking).
EN 1992-1-1
Weathering/Finishing Course
Mandatory 20 mm thick plaster (lime or cement) laid to slope, integral to the system.
Not part of the structural standard; specified under separate building envelope/roofing codes.
General practice with EN/ACI
⚠ Verify details from original standards before use
A composite floor/roof construction using timber or steel joists, a layer of specially sized bricks laid on edge diagonally, and a top layer of lime or brick-bat concrete.
What is the standard spacing for joists in a Madras terrace?+
Joists are typically spaced between 300 mm and 450 mm center-to-center to safely support the diagonal brickwork.
How long should the concrete course be cured?+
The concrete course should be kept continuously damp and cured for a minimum of 14 days.