The thickness of a brick wall depends on brick dimensions, bond arrangement, mortar joints and the building design. IS 1077:1992 specifies brick dimensions and Clause 6.1.1 specifies actual modular brick sizes of 190 × 90 × 90 mm and 190 × 90 × 40 mm. Clause 6.1.2 lists non-modular sizes of 230 × 110 × 70 mm and 230 × 110 × 30 mm. law.resource.org
Typical Modular Brick Wall Thicknesses
Using the modular brick dimensions above and assuming 10 mm mortar joints where required across the wall thickness, the following dimensions can be derived:
| Wall type | Unplastered masonry thickness | Nominal coordinating thickness | Finished thickness with 10–15 mm plaster on each face |
|---|---|---|---|
| Half-brick wall | 90 mm | 100 mm | 110–120 mm |
| One-brick wall | 190 mm | 200 mm | 210–220 mm |
| One-and-a-half-brick wall | 290 mm | 300 mm | 310–320 mm |
| Two-brick wall | 390 mm | 400 mm | 410–420 mm |
Note: These are derived wall dimensions, not a wall-thickness table prescribed by IS 1077. Actual thickness depends on the bond, brick tolerances and joint thickness.
For example:
\[ \text{One-and-a-half-brick thickness}=190+10+90=290\text{ mm} \]\[ \text{Two-brick thickness}=190+10+190=390\text{ mm} \]
Non-Modular Brick Walls
For bricks measuring 230 × 110 × 70 mm, the typical unplastered thickness is:
- Half-brick wall: 110 mm.
- One-brick wall: 230 mm.
Therefore, a one-brick wall with 15 mm plaster on each face has a finished thickness of:
\[ 230+15+15=260\text{ mm} \]
The term “9-inch wall” is a common approximate description. A 115 mm half-brick wall corresponds to a different regional brick width; it should not be derived from a brick specified as 110 mm wide.
Actual, Nominal and Finished Thickness
Actual masonry thickness is the physical thickness of the brickwork, including joints within it. Nominal coordinating thickness includes the allowance used for modular coordination; it is not simply an arbitrary rounded dimension. Finished thickness includes plaster, render or other specified finishes.
\[ \text{Finished thickness} = \text{Masonry thickness} + \text{Finish on the first face} + \text{Finish on the second face} \]
Drawings and quantity calculations should clearly identify which dimension is being used. Plaster should be measured separately when the masonry item excludes finishes. Cement mortar may be used for both brick joints and plastering, so distinguish them by their function.
Selection of Wall Thickness
A half-brick wall is commonly used for non-load-bearing partitions. Thicker walls may serve as external walls or load-bearing masonry, subject to design. Compliance of the bricks with IS 1077 does not, by itself, establish the structural adequacy of the wall. Wall thickness must also satisfy the applicable structural design requirements.
Reference: Bureau of Indian Standards. (1992). IS 1077:1992—Common burnt clay building bricks—Specification (Fifth revision), clauses 6.1.1–6.1.2. law.resource.org