Restricted Zones
27.F.02 A restricted zone must be established whenever a masonry wall is being constructed.
The restricted zone is created to keep masons and other tradesmen away from a wall under construction when winds exceed critical velocities until the wall is completely tied into the rest of the structure. The restricted zone must:
- Be established prior to the start of construction on the wall;
- Be equal to the height of the wall being constructed plus 4 ft (1.2 m), and must run the entire length of the wall;
- Be established on the side of the wall that will be not be scaffolded;
- Be restricted to entry only by employees actively engaged in constructing the wall; no other employees must be permitted to enter the zone;
- Be evacuated during the initial period of construction when wind speeds exceed 20 mph;
- Be evacuated during the intermediate period of construction when wind speeds exceed 35 mph;
- Remain in place until the wall is adequately supported to prevent overturning and to prevent collapse unless the height of the wall is over 8 ft (2.4 m), in which case the restricted zone must remain in place until the requirements of this Section 27.F.02 have been met.
- For multi-story structures, the restricted zone must be determined by a QP.
27.F.03 All masonry walls over 8 ft (2.4 m) in height must be adequately braced to prevent overturning and to prevent collapse unless the wall is adequately supported so that it will not overturn or collapse. The bracing must remain in place until permanent supporting elements of the structure are in place.
27.F.04 Each employer having workers in the restricted zone must monitor the wind speed continuously while the work is in progress and evacuate employees as required above.
- Wind speeds must be 3-second gust speeds.
- Instrument methods must accurately measure wind speed to +/- 2 mph and instruments must be properly maintained.
27.F.05 The CP must inspect unsupported masonry walls, including the wall bracing system, for visible defects at the beginning of each shift and after any occurrence that could affect the structural integrity of the wall or wall bracing system.
27.F.06 Any damaged or weakened brace element must be repaired or replaced before work is permitted in the restricted zone in the vicinity of the damaged brace or weakened brace element. A CP must supervise the repairs.
27.F.07 A structural engineer, familiar with the work being performed, must design the repairs to the wall. Repairs must not be performed without the approval of the project structural designer of record.
27.F.08 Scaffolds for masonry construction workers must not be used to provide temporary lateral support of masonry walls.
27.F.09 Cleanouts must be on the side of the masonry wall opposite to the scaffolding.
27.F.10 Fall protection must be provided to masonry workers exposed to falls of 6 ft (1.8 m) or more. > See Section 21.
Knowledge Check Choose the best answer for the question.
27-8. How far must the restricted zone extend from a masonry wall along its entire length while it's being constructed?
You forgot to answer the question!