1. (1) You must make sure supported scaffolds with a height to least base dimension ratio of greater than four to one are prevented from tipping by one or more of the following:

   1. (a) Guying;
   2. (b) Tying;
   3. (c) Bracing;

   4. (d) Other equivalent means.

      Note:

      The least base dimension includes outriggers, if used.

2. (2) You must install guys, ties, and braces where horizontal members support both the inner and outer legs of the scaffold.

3. (3) You must install guys, ties, and braces:

   1. (a) According to the scaffold manufacturer's recommendations; or

   2. (b) At all points where the following horizontal and vertical planes meet:

      1. (i) First vertical level at a height equal to four times the least base dimension.

      2. (ii) Subsequent vertical levels every:

         1. (A) Twenty feet (6.1 m) or less for scaffolds having a width of three feet (0.91 m) or less;
         2. (B) Twenty six feet (7.9 m) or less for scaffolds more than three feet (0.91 m) wide.

      3. (iii) Horizontally at:

         1. (A) Each end of the scaffold; and

         2. (B) Intervals of thirty feet (9.1 m) or less.

            Note:

            The thirty-foot horizontal intervals are measured from one end of the scaffold to the other.

4. (4) You must make sure the highest level of guys, ties, or braces is no further from the top of the scaffold than a distance equal to four times the least base dimension.

5. (5) You must make sure scaffolds that have an eccentric load applied or transmitted to them, such as a cantilevered work platform, are prevented from tipping by one or more of the following:

   1. (a) Guying;
   2. (b) Tying;
   3. (c) Bracing;
   4. (d) Outriggers;

   5. (e) Other equivalent means.

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[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050. WSR 15-23-086, § 296-874-40004, filed 11/17/15, effective 12/18/15. Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, 49.17.060. WSR 07-17-026, § 296-874-40004, filed 8/7/07, effective 10/6/07; WSR 07-03-163, § 296-874-40004, filed 1/24/07, effective 4/1/07; WSR 05-01-054, § 296-874-40004, filed 12/7/04, effective 3/1/05.]