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Subchapter 4. Construction Safety Orders
Article 31. Demolition

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§1735. Demolishing Buildings.

(a) Utility companies shall be notified and all utility service shut off, capped, or otherwise controlled, at the building or curb line before starting demolition, unless it is necessary to use electricity or water lines during demolition. If use is necessary, the utility services shall be relocated or rearranged as necessary and protected from physical damage.

(b) It shall also be determined if any type of hazardous chemicals, gases, explosives, flammable materials, or similarly dangerous substances have been used in any pipes, tanks, or other equipment on the property. When the presence of any such substances is apparent or suspected, testing and purging shall be performed and the hazard eliminated before demolition is started.

(c) Pipe-covering insulation, steel beam and column fire protection, and heating, ventilating and air-conditioning duct work shall be surveyed for asbestos. If asbestos is present, the employer shall comply with Section 1529.

(d)(1) Prior to starting demolition operations, all structural or other hazardous deficiencies noted during the survey required by Section 1734(b)(1) shall be shored, braced or otherwise corrected as recommended in the survey.

(2) Walls, which serve as retaining walls to support earth or adjoining structures, shall not be demolished until the hazard from moving ground has been eliminated by sloping, shoring or, where necessary, adjoining structures have been properly underpinned.

(3) Walls, which are to serve as retaining walls against which debris will be piled, shall not be so used unless determined to be capable of safely supporting the imposed load.

(4) During demolition, continuing inspections shall be made as the work progresses to detect hazards resulting from weakened or deteriorated floors or walls, or loosened material.

Employees shall not be permitted to work where such hazards exist until they are corrected by shoring, bracing, or other effective means.

(e) In demolishing any building or structure or alteration involving partial demolition thereof, all material displaced, unless required for reconstruction, shall be transported immediately to the ground. The amount of material stored upon any structure or any portion of such structure shall not exceed its safe carrying capacity.

(f)(1) Except for the cutting of holes in floors for chutes, holes through which to drop materials, preparation of storage space, and similar necessary preparatory work, the demolition of exterior walls and floor construction shall begin at the top of the structure and proceed downward and each story of exterior wall and floor construction shall be removed and dropped into the storage space before commencing the removal of exterior walls and floors in the story next below.

(2) Any openings cut in a floor for the disposal of materials shall be no larger in size than 25 percent of the aggregate of the total floor area, unless the lateral supports of the removed flooring remain in place. Floors weakened or otherwise made unsafe by demolition operations shall be shored to safely support the intended imposed load from demolition operations.

(3) Flooring boards may be removed from not more than one floor above grade to provide storage space for debris, provided falling material is not permitted to endanger structural stability.

(4) When wood floor beams serve to brace interior walls or free-standing exterior walls, such beams shall be left in place until other equivalent support can be installed to replace them.

NOTE: For selective demolition by explosives of buildings and structures, refer to appropriate Articles of Group 18, Explosives and Pyrotechnics of the General Industry Safety Orders and this Article.

(g) Sections of walls shall not be allowed to fall upon floors supported by wood joists or other floors unable to withstand such impact.

(h) Walkways that meet the requirements of Section 1624 shall be provided where necessary for access.

(i) Walking across exposed floor joists, steel beams, or girders is prohibited.

(j) All persons on demolition projects shall be protected from falling material at employee entrances to multi-story structures being demolished, by sidewalk sheds or canopies or both, providing protection extending from the face of the building for a minimum of 8 feet. All such canopies shall be at least two feet wider than the building entrances or openings (one foot wider on each side thereof) and shall be capable of sustaining a load of 150 pounds per square foot.

(k) Exterior wall openings on all floors shall be protected to a height of not less than 42 inches, except on the ground floor and the floor being demolished.

(l) Where a hazard exists from fragmentation of glass, all glazed openings shall be removed at least one floor below the working level.

(m)(1) No wall section, which is more than one story or 12 feet in height, shall be permitted to stand alone without lateral bracing, unless a civil engineer, currently registered in California, has submitted engineering data to the Division substantiating the capability of the wall to stand without lateral support.

(2) All walls shall be left in a stable condition at the end of each work day.

(n) Steel construction shall be dismantled column length by column length, and tier by tier (columns may be two-story lengths.) Any structural unit being dismantled shall not be overstressed.

(o) Planks spanning the distance between adequate beams shall be used where necessary as a substitute for weakened floors, and as access walkways over open or weakened areas.

When demolishing floors and roofs, employees shall be prohibited from working below this activity. Demolition of floor spaces shall continue until all unsupported flooring is removed. When employees are required to remove floor support beams, wall sections, etc., by hand, scaffolding as described in Article 21 of the Construction Safety Orders or elevating work platforms and aerial devices as described in Article 24 of the General Industry Safety Orders shall be provided and used where necessary to insure employee safety.

(p)(1) Stairways designated as means of access shall be maintained clear for use within two floors or twenty-four feet of the demolition work above.

(2) Ladders shall be provided for these remaining two floors and shall be constructed and maintained in accordance with Article 25, Ladders. Other access ways shall be entirely closed off at all times.

(3) Walkways or ladders shall be provided to enable employees to safely reach or leave any scaffold or wall.

(q) In a multi-story building, when a stairwell is being used for access or egress, it shall be properly illuminated by either natural or artificial means, and completely and substantially covered over at a point not less than two floors below the floor on which work is being performed, and access to the floor where the work is in progress shall be through a properly lighted, protected, and separate passageway.

(r)(1) Construction passenger elevators for hoisting employees shall be provided on demolition projects on multi-story buildings seven or more floors or seventy-two feet or more in height.

(2) Landings shall be provided for the passenger elevators on or in buildings at intervals not to exceed four floors or forty-eight feet.

(3) Where there is doubt concerning structural integrity or engineering data indicates attachment of an elevator may jeopardize the strength of the building or structure, the Division may permit alternate methods of installation. Other means of employee access may also be allowed by the Division where the above is clearly impractical.

(s) If the method of demolition leaves the structural steel frame in place, then the tier of beams next below the tier from which beams and columns are being removed shall be planked over, unless safety nets are used or the floor of such tier has not been removed. Necessary openings for material handling are allowed. All loose material shall be removed from the steel frame as demolition progresses downward.

(t) Provisions for dust control shall include the use of water to keep material or debris sufficiently wet or other equivalent steps taken to prevent dust from rising.

(u) Mechanical equipment shall not be used on floors or working surfaces unless a qualified person has determined that such floors or surfaces are of sufficient strength to support the imposed load.

(v) Where mechanical equipment is used for demolition work, floor openings shall have curbs or stop-logs to prevent equipment from running over the edge.

(w) No salvage of materials shall be permitted during demolition operations on any building, structure, falsework or scaffold more than three stories high or the equivalent height for which a permit is required.

NOTE: For mechanical demolition of buildings and structures, refer to appropriate sections of Article 10 of the Construction Safety Orders, Article 93 of the General Industrial Safety Orders, and this Article.

Note: Authority cited: Sections 142.3, Labor Code. Reference: Sections 142.3 and 6401.5, Labor Code.


1. Amendment filed 2-11-72, effective thirtieth day thereafter (Register 72, No. 7).

2. Amendment filed 5-21-75, effective thirtieth day thereafter (Register 75, No. 21).

3. Amendment of subsection (n) filed 10-18-77; effective thirtieth day thereafter (Register 77, No. 43).

4. New subsection (z) filed 4-3-78; effective thirtieth day thereafter (Register 78, No. 13).

5. Amendment filed 12-4-86; effective thirtieth day thereafter (Register 86, No. 49).

6. Editorial correction of printing error in subsection (o) (Register 92, No. 33).

7. Amendment filed 5-22-95; operative 6-21-95 (Register 95, No. 21).

8. Editorial correction redesignating erroneous second subsection (g) as subsection (q) (Register 2010, No. 34).

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