Wall thickness nomenclature — nominal thickness of a one-brick wall (in millimetres) In standard modular brick masonry, what is the nominal thickness (in mm) of a one-brick thick wall including mortar joints, as used in drawings and specifications?
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A90 mm
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B150 mm
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C190 mm
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D200 mm
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E—
Answer
Correct Answer: 200 mm
Explanation
Introduction / Context:Masonry wall thickness is often specified by “half-brick”, “one-brick”, “one-and-a-half brick”, etc. For quantity estimation and detailing, these correspond to standard nominal dimensions including mortar joints, not just the unit size.
Given Data / Assumptions:
- Standard modular brick size around 190 × 90 × 90 mm.
- Mortar joint thickness about 10 mm.
- Nominal dimensions used for specification.
Concept / Approach:
A one-brick wall is nominally 200 mm thick (i.e., length of a standard brick plus mortar). By contrast, a half-brick wall is about 100 mm, and a three-quarter-brick wall about 150 mm. The 190 mm option corresponds roughly to the unit length without the joint and is not the nominal wall thickness used for specification.
Step-by-Step Solution:
Define “one-brick” thickness = brick length + mortar ≈ 190 + 10 = 200 mm.Compare with other nominal categories: half-brick ≈ 100 mm; three-quarter ≈ 150 mm.Select nominal specification value → 200 mm.Verification / Alternative check:
Schedules of rates and building specs typically list one-brick walls as 200 mm nominal for BOQ and drawings.
Why Other Options Are Wrong:
- 90 mm and 150 mm correspond to half and three-quarter brick categories.
- 190 mm omits the mortar allowance and is not the nominal specification.
Common Pitfalls:
- Mixing unit dimensions with wall thickness nomenclature including joints.
Final Answer:
200 mm.