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IS 3952 : 1988burnt clay hollow bricks for walls and partitions - Specification

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BS EN 771-1 · ASTM C652 · AS/NZS 4455.1
CurrentSpecializedSpecificationBIMMaterials Science · Clay and Stabilized Soil Products
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OverviewValues5InternationalTablesFAQ4Related

IS 3952:1988 is the Indian Standard (BIS) for burnt clay hollow bricks for walls and partitions - specification. This standard specifies the dimensions, physical requirements, and testing procedures for burnt clay hollow bricks used in load-bearing and non-load-bearing walls and partitions. It defines limits for compressive strength, water absorption, and efflorescence to ensure structural integrity and durability.

burnt clay hollow bricks for walls and partitions - Specification

Overview

Status
Current
Usage level
Specialized
Domain
Materials Science — Clay and Stabilized Soil Products
Type
Specification
International equivalents
BS EN 771-1:2011+A1:2015 · BSI / CEN (British Standards Institution / European Committee for Standardization), UK / EuropeASTM C652-21 · ASTM International, USAAS/NZS 4455.1:2008 · Standards Australia / Standards New Zealand, Australia / New Zealand
Typically used with
IS 1077IS 3495IS 5454
Also on InfraLens for IS 3952
5Key values1Tables4FAQs

BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.

Practical Notes
! Hollow bricks provide excellent thermal and sound insulation and reduce the dead load of the structure compared to solid masonry.
! Compressive strength must always be calculated based on the gross area of the brick, not the net area excluding voids.
! Ensure bricks are thoroughly soaked in water before use to prevent them from absorbing moisture from the mortar, which weakens the bond.
Frequently referenced clauses
Cl. 4Dimensions and TolerancesCl. 5.1Compressive StrengthCl. 5.2Water AbsorptionCl. 5.3EfflorescenceCl. 6Sampling and Criterion for Conformity
Pulled from IS 3952:1988. Browse the full clause & table index below in Tables & Referenced Sections.
burnt clayhollow bricksmasonryclay products

International Equivalents

Similar International Standards
BS EN 771-1:2011+A1:2015BSI / CEN (British Standards Institution / European Committee for Standardization), UK / Europe
HighCurrent
Specification for masonry units - Part 1: Clay masonry units
Specifies requirements for clay masonry units, including hollow/perforated types, for use in masonry walls.
ASTM C652-21ASTM International, USA
HighCurrent
Standard Specification for Hollow Brick (Hollow Masonry Units Made from Clay or Shale)
Covers hollow brick made from clay or shale, fired to incipient fusion, for use as structural and facing units.
AS/NZS 4455.1:2008Standards Australia / Standards New Zealand, Australia / New Zealand
MediumCurrent
Masonry units and segmental pavers and flags - Part 1: Masonry units
Broader scope covering various masonry materials, but includes specifications for cored or perforated clay units.
BS 3921:1985BSI (British Standards Institution), UK
HighWithdrawn
Specification for clay bricks
Historically equivalent standard specifying requirements for clay bricks, including perforated types.
Key Differences
≠Classification System: IS 3952 classifies bricks by compressive strength into classes (e.g., Class 5, 10, 15 N/mm²). EN 771-1 does not use classes, requiring manufacturers to declare a normalized mean compressive strength. ASTM C652 uses Grades (SW, MW for weathering) and Types (HBS, HBX, HBA, HBB for dimensional and property control).
≠Void Percentage: IS 3952 specifies that the total area of voids shall not exceed 45% of the gross area. ASTM C652 allows for a higher void percentage, up to 60% of the gross cross-sectional area.
≠Dimensional Tolerances: IS 3952 specifies fixed percentage-based tolerances (e.g., ±5% on length). EN 771-1 uses tolerance categories (T1, T2, T_m) that a manufacturer declares, offering more flexibility and precision levels.
≠Water Absorption Limits: IS 3952 sets a maximum water absorption of 20% (for Class 10 and above) by 24-hr cold water immersion. ASTM C652 specifies different limits based on grade and a 5-hour boiling test (e.g., 17.0% for Grade SW).
Key Similarities
≈Base Material: All standards specify that the units shall be made from burnt clay, shale, or similar naturally occurring fired-earth materials.
≈Fundamental Properties: Core performance characteristics such as compressive strength, water absorption, and dimensional stability are mandatory tests across all the standards.
≈Efflorescence Control: All standards recognize and include provisions for testing and classifying the potential for efflorescence (soluble salts), although the rating systems differ.
≈Intended Use: The primary application for units specified under all these standards is for load-bearing and non-load-bearing walls and partitions in building construction.
Parameter Comparison
ParameterIS ValueInternationalSource
Compressive Strength (Typical Class)Class 10 (Average not less than 10 N/mm²)Manufacturer declares mean compressive strength, e.g., '10 N/mm²' (No predefined classes)BS EN 771-1
Max Water Absorption (24hr cold)20% by mass (for bricks of Class 10 and above)Not directly specified; 17.0% by mass (by 5-hr boil for Grade SW)ASTM C652-21
Maximum Void Area45% of gross area60% of gross cross-sectional areaASTM C652-21
Minimum Shell Thickness (face)15 mm19 mm (3/4 in.) for Type HBS; 25 mm (1 in.) for HBX, HBA, HBBASTM C652-21
Minimum Web Thickness10 mm19 mm (3/4 in.) on units with voids >25% gross areaASTM C652-21
Efflorescence Test ResultRated as 'Slight', 'Moderate', or 'Heavy'Rated as 'Effloresced' or 'Not Effloresced' based on visual inspectionASTM C67 (Test Methods)
Length Tolerance± 5%Category T2: ±4 mm for a 190 mm brick (declared by manufacturer)BS EN 771-1
⚠ Verify details from original standards before use

Key Values5

Quick Reference Values
minimum compressive strength3.5 N/mm² (based on gross area)
maximum water absorption20% by weight
minimum shell thickness11 mm
minimum web thickness8 mm
permissible efflorescenceNot more than 'Slight'

Tables & Referenced Sections

Key Tables
Table 1 - Standard Dimensions of Hollow Bricks
Key Clauses
Clause 4 - Dimensions and Tolerances
Clause 5.1 - Compressive Strength
Clause 5.2 - Water Absorption
Clause 5.3 - Efflorescence
Clause 6 - Sampling and Criterion for Conformity

Related Resources on InfraLens

Cross-Referenced Codes
IS 1077:1992Common Burnt Clay Building Bricks - Specifica...
→
IS 3495:1992Methods of Tests of Burnt Clay Building Brick...
→
IS 5454:1978Methods of sampling of clay building bricks
→

Frequently Asked Questions4

What is the minimum compressive strength required for burnt clay hollow bricks?+
The minimum compressive strength is 3.5 N/mm² when calculated over the gross area.
What is the maximum permissible water absorption for these bricks?+
Water absorption should not exceed 20% by weight after 24 hours of immersion in cold water.
What is the minimum thickness allowed for the outer shells and inner webs of the hollow brick?+
The minimum thickness of any outer shell is 11 mm, and the minimum thickness of any inner web is 8 mm.
What are the common standard dimensions specified in this code?+
Standard modular sizes are typically 190 x 190 x 90 mm, 190 x 90 x 90 mm, and 290 x 90 x 90 mm.

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