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Subchapter 4. Construction Safety Orders
Article 20. Temporary Floors
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§1635. Floors, Walls and Structural Steel Framed Buildings.

(a) For multifloor buildings, other than structural steel framed buildings, the following shall apply:

(1) Every building shall have the joists, beams, or girders of floors below the floor or level where any work is being done, or about to be done, covered with flooring laid close together, or with other suitable material to protect workers engaged in such building from falling through joists or girders, and from falling substances, whereby life or safety is endangered.

(2) Every building which is of reinforced concrete construction, with reinforced concrete floors, shall have the floor filled in, either with forms or concrete, on each floor before the commencement of work upon the walls of the second floor above or the commencement of work upon the floor of the next floor above.

(3) Every building having wooden floors other than a steel frame building shall have the underflooring, if double flooring is to be used, laid on each floor within the time prescribed above for reinforced concrete floors. Where single wooden floors are to be used, each floor shall be planked over within the time prescribed above for reinforced concrete floors.

(4) If a span of a floor on a building exceeds 13 feet, an intermediate beam shall be used to support the temporary flooring, but spans not to exceed 16 feet may be covered by three-inch planks without an intermediate beam. The intermediate beam shall be of a sufficient strength to sustain a live load of 50 pounds per square foot of the area supported.

(5) If building operations are suspended and the temporary flooring required by this article is removed, the building shall be replanked upon the resumption of work so that every worker at work has a covered floor not more than two stories below.

(6) Planked floors on buildings shall be tightly laid together of proper thickness, grade and span to carry the working load; such working load to be assumed as at least 25 pounds per square foot.

(7) Fall protection shall be required in accordance with Article 24.

(8) No person shall proceed with any work assigned to or undertaken or require or permit any other person to proceed with work assigned to or undertaken by either, unless the planking or nets required by this article are in place.

(b) For multifloor structural steel framed buildings more than two stories high, the following shall apply: These provisions shall apply to buildings erected in tiers or stories and shall not apply to steel framed buildings having large open spans or areas such as, mill buildings, gymnasiums, auditoriums, hangars, arenas, or stadiums.

(1) The derrick or working floor of every building shall be solidly decked over its entire surface except for access openings.

(2) There shall be a tight and substantial temporary floor within two floors below and directly under that portion of each tier of beams on which erection, riveting, bolting, welding or painting is being done. For operations of short duration of exposure to falling, fall protection shall be required as set forth in Article 24 and Section 1710.

(3) Temporary floors shall be wood planking of proper thickness, grade and span to carry the working load, but shall not be less than two inches thick, full size undressed.

(4) Provision shall be made to secure temporary flooring against displacement by strong winds or other forces.

(5) Planks shall extend a minimum of 12 inches beyond centerline of their supports at each end.

(6) Wire mesh or plywood (exterior grade) shall be used to cover openings adjacent to columns where planks or metal decking do not fit tightly. The materials used must be of sufficient strength as required by Section 1632(b) to provide fall protection for personnel and prevent objects from falling through.

(7) Metal decking where used in lieu of wood planking shall be of equivalent strength and shall be laid tightly and secured to prevent movement.

(8) Floor planks or metal decking that are temporarily removed for any reason whatsoever shall be replaced as soon as work requiring their removal is completed or the open area shall be properly guarded.

(9) Prior to removal of temporary floor planks or metal decking, employees shall be instructed by assigned supervision the steps to be taken to perform the work safely and in proper sequence.

(10) When gathering and stacking temporary floor plank on a lower floor, in preparation for transferring such plank for use on an upper working floor, the steel erector's personnel shall remove such plank successively, working toward the last panel of such floor, so that the work is always being done from the planked floor.

(11) When gathering and stacking temporary floor planks from the last panel, the steel erector's personnel assigned to such work shall be protected by a personal fall protection system used in accordance with Article 24 and Section 1710.

(12) The sequence of erection, bolting temporary guying, riveting and welding shall be such as to maintain the stability of the structural frame at all times during construction. This applies to the dead weight of the structure, plus weight and working reactions of all construction equipment placed thereon plus any external forces that may be applied.

(13) Where a building is being constructed in sections, each section constitutes a building.

(14) Personal fall protection and nets shall be required in accordance with Article 24 and Section 1710.

(15) No person shall proceed with any work unless the planking and metal decking, or nets required by this article are in place.

(c) Special Provisions Applicable to Floor Openings. Section 1632(b) applies to floor openings at locations where steel erection work is taking place. This subsection applies where work is in progress that requires floor openings to be uncovered. For such work, all of the following requirements shall apply:

(1) The floor or working level where such work is in progress shall be under the exclusive control of the steel erection employer and shall be barricaded to prohibit entry by unauthorized personnel.

(2) The floor area adjacent to the floor opening shall be barricaded or the floor opening shall be covered when not attended by steel erection personnel.

(3) All planking and other materials used to cover floor openings shall be capable of safely supporting the greater of 400 pounds or twice the weight of the employees, equipment and materials that may be imposed on any one square foot area of the cover at any time. The cover shall have not less than 12 inches of bearing on the surrounding structure.

(4) All floor opening covers shall bear a sign stating, "OPENING-DO NOT REMOVE", in 2 inch high, black bold letters on a yellow background.

(5) The placement of covers shall be verified by a qualified person prior to each shift and following strong wind conditions.

(6) Workers shall be instructed and required to adhere to the following:

(A) Keep covers in place when not engaged in work requiring the opening to be uncovered, and

(B) Never remove a cover by walking forward or by stepping into an area where they cannot directly observe the surface their feet will touch.

(7) After work requiring floor openings to be uncovered has been completed and prior to allowing other trades in the work area, the guarding and covers for floor openings shall meet the provisions of Section 1632(b).

<General Materials (GM) - References, Annotations, or Tables>

Note: Authority cited: Section 142.3, Labor Code. Reference: Sections 142.3, 7101, 7102, 7103, 7104, 7105, 7107, 7108, 7109, 7251, 7252, 7253, 7254, 7255, 7256, 7257, 7258, 7259, 7261, 7262, 7263, 7264, 7265 and 7266, Labor Code.


1. Amendment filed 4-21-72 as procedural and organizational; effective upon filing (Register 72, No. 17).

2. Amendment filed 1-14-86; effective thirtieth day thereafter (Register 86, No. 3).

3. Change without regulatory effect correctly numbering subsection (b)(2) filed11-3-92; operative 12-3-92 pursuant to title 1, section 100, California Codeof Regulations (Register 92, No. 45).

4. Amendment of subsection (b)(14) filed 7-2-98; operative 8-1-98 (Register98, No. 27).

5. Amendment of subsections (a), (a)(7), (b)(2) and (b)(6) filed 5-1-2002; operative 5-1-2002. Submitted to OAL for printing only pursuant to LaborCode section 142.3(a)(3) (Register 2002, No. 18).

6. Amendment of subsections (b)(6) and (b)(11) filed 7-3-2003; operative 8-2-2003 (Register 2003, No. 27).

7. Amendment of subsections (b)(2), (b)(8)-(9), (b)(11) and (b)(14)-(15), new subsections (c)-(c)(7) and amendment ofNote filed 1-25-2006; operative 2-24-2006 (Register 2006, No. 4).

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