Technical Booklet D Structure·Page 76·4C.26
Interruption of lateral support at openings
Where openings in floors or roofs adjoin supported walls and interrupt lateral support, maximum opening length is 3 m parallel to the wall, and connection provisions must be maintained on both sides of the opening with straps spaced closer than 2 m.
Where an opening in a floor or roof for a stairway or the like adjoins a supported wall and interrupts the continuity of lateral support, the following provisions should be made –
(a) the maximum permitted length of the opening should be 3 m, measured parallel to the supported wall;
(b) where a connection is provided by means other than by anchor, this must be provided throughout the length of each portion of the wall situated on each side of the opening;
(c) where connection is provided by tension straps, these must be spaced closer than 2 m on each side of the opening to provide the same number of straps as if there were no opening; and
(d) no other interruption of lateral support is permissible.
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