Technical Booklet D Structure·Page 67·4C.12
Cavity wall tie spacing requirements
Wall ties must be spaced at 900 mm horizontally and 450 mm vertically overall, with tighter spacing of 300 mm vertically within 225 mm of openings, movement joints, and roof verges.
The cavity wall ties should have a horizontal spacing of 900 mm and a vertical spacing of 450 mm, which is equivalent to 2.5 ties per square metre. Wall ties should also be spaced not greater than 300 mm apart vertically, within a distance of 225 mm from the vertical edge of any opening, movement joint and roof verge.
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