This code outlines the materials, design guidelines, and construction procedures for jack-arch type built-up floors and roofs. It details the specifications for rise-to-span ratios, steel joist placement, tie rod requirements, and brick-laying techniques to ensure structural stability.
Code of Practice for Construction of Jack-Arch Type of Bult-up Floor or Roof
Quick Reference Values
Recommended rise of arch1/8 to 1/12 of the span
Minimum thickness of brick archHalf brick thickness (approx 115 mm)
Minimum bearing of steel joists on walls100 mm
Typical spacing of tie rods1.2 m to 1.8 m apart
Practical Notes
Tie rods are absolutely critical in the end spans to resist the outward lateral horizontal thrust of the arches.
Centering must only be removed after the mortar has gained adequate strength to prevent the arch from collapsing under its own weight.
Ensure proper keying of bricks and complete filling of mortar joints (especially the crown) to maintain optimal arch action.