Setting out
Stretcher offset / bond module
- where
- module (mm)
- unit length (mm)
- joint (mm)
- lap offset (mm)
- offset fraction
Explain this equation
This gives the bond module and the setting-out offset for a chosen fraction of it, such as a half lap in stretcher bond or a quarter lap.
l is the unit length and j the joint, both in mm. Their sum m is the module, the distance from one perpend to the next along a course. f is the fraction of the module you want to offset by, for example 0.5 for half bond or 0.25 for quarter bond. e is the resulting offset in mm.
Perpends repeat every module, so offsets between courses are measured as fractions of the module, not of the bare unit length. That is why the joint is added before multiplying by f.
A 215 mm brick with a 10 mm joint gives a 225 mm module, so a half lap is 112.5 mm and a quarter lap is 56.25 mm.
Watch out: this is a setting-out distance, not the length of a cut brick. Check minimum lap and bond requirements in the design.
Calculate a fraction of a coordinating module.
Enter your values to see the result.
Good to know
This is a setting-out offset, not a cut-brick length. Check minimum lap, closers and structural bond requirements in the design.
Sources
- Geometry / arithmetic
Estimates are not design approval or British Standards compliance checks. Structural arch, retaining-wall, wind, foundation, lintel and masonry-capacity design are not performed. Use the project engineer’s specification.