Masonry Control-Joint Layout

Lays out masonry control joints by the NCMA empirical rule.

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Example

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Details, formula, and sources

max spacing = min(1.5 x wall height, project cap); panels = ceil(length / max spacing); joints = panels - 1. An 80 ft CMU wall 16 ft tall caps at 24 ft, so 4 panels of 20 ft with 3 control joints; a 120 ft wall at the same spacing is 5 panels and 4 joints - the height sets the spacing, the length sets the count. Keeps shrinkage cracking in the joints, not the field. Distinct from concrete-slab control-joint spacing.

max_spacing_ft = min(1.5 x wall_height_ft, max_spacing_cap_ft); panels = ceil(wall_length_ft / max_spacing_ft); joints = panels - 1; panel_length_ft = wall_length_ft / panels.

Masonry control-joint rule by name (spacing the lesser of 1.5x the height or a project cap; panels/joints from the length); NCMA empirical guideline.

The 1.5x-height rule of thumb is public NCMA guidance; the project cap and reinforcement adjustment come from the project standard.

Estimate. AHJ and licensed professional govern.

Field names used by the API: wall_length_ft, wall_height_ft, max_spacing_cap_ft, max_spacing_ft, panels, joints, panel_length_ft

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