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Home › Publications › OHS Regulation › Part 20 Construction, Excavation and Demolition

Part 20 Construction, Excavation and Demolition

Construction, Excavation and Demolition Definitions

20.1 Definitions

In this Part

"adjacent to an excavation" means within a distance less than or equal to the overall depth of the excavation, measured from a vertical line through the toe of the excavation face;

"construction project" means any erection, alteration, repair, dismantling, demolition, structural or routine maintenance, painting, land clearing, earth moving, grading, excavating, trenching, digging, boring, drilling, blasting, concreting, the installation of any machinery or any other work deemed to be construction by the Board;

"demolition" means tearing down, destruction, breakup, razing or removal of the whole or part of a building or structure, or of free standing machinery or equipment that is directly related to the function of the structure;

"excavation" means any cut, cavity, trench or depression in the earth's surface resulting from rock or soil removal;

"formwork" includes the foundation, supporting structure, and mould into which concrete will be placed;

"formwork designer" means the professional engineer responsible for the design of formwork;

"tilt-up construction" means a system of building construction in which concrete wall panels are placed in position in the permanent structure and temporarily braced or supported;

"trench" means an excavation less than 3.7 m (12 ft) wide at the bottom, over 1.2 m (4 ft) deep, and of any length.

General Requirements

20.1A Qualified contractor

If a person agrees with the owner to be the prime contractor as provided in section 118 of Part 3 of the Workers Compensation Act, then that person must be qualified.

20.2 Notice of project

(1) The owner or, if the owner engages another person to be the prime contractor, then that person must ensure that the Board receives, in writing or by fax, a notice of project (NOP) at least 24 hours before starting a construction project if

(a) the total cost of labour and materials for the work exceeds $100 000, or

(b) all or part of the permanent or temporary works, except pre-engineered or pre-manufactured building and structural components, are required to be designed by a professional engineer, or

(i) the removal, encapsulation or enclosure of friable asbestos building materials, or

(ii) the demolition, dismantling or repair of any building or structure, or parts thereof, in which insulating materials containing asbestos have been used, or in which asbestos products have been manufactured, or

(iii) an abatement project or other activity involving significant disturbance of lead-containing coatings on buildings or structures, or

(iv) similar activities which may expose workers to a significant risk of occupational disease, or

(d) the construction project is a new erection, a major alteration, a structural repair or a demolition of

(i) a building more than 2 stories high or more than 6 m (20 ft) in height, or

(ii) a bridge, or

(iii) an earth or water retaining structure more than 3 m (10 ft) in height, or

(iv) a silo, chimney or similar structure more than 6 m (20 ft) in height, or

(e) workers will be working in a compressed air atmosphere or in a caisson, tunnel, underground working or cofferdam, or

(f) the construction project includes a trench more than 1.2 m (4 ft) in depth and over 30 m (100 ft) in length or includes another type of excavation more than 1.2 m (4 ft) in depth, which a worker may be required to enter.

(2) The notice of project required by subsection (1) must contain

(a) the name and address of the owner and, if applicable, any other person engaged to be the prime contractor for the project,

(b) the municipal address of the project, or its location in relation to the nearest highway,

(d) the starting date and the anticipated duration of the project,

(e) the estimated total cost of labour and materials for the project, and

(f) if the project involves an activity listed in subsection (1)(c), detailed written work procedures which will be used to minimize the risk to workers who might be exposed to a hazardous material specified by that subsection.

(3) A copy of the notice of project must be posted at the construction site before work commences.

(4) If it is necessary to do immediate work in order to prevent injury to workers or damage to property, work on the project may commence immediately, and the nearest Board office must be provided with an NOP at the earliest possible time.

(5) If a shaft, tunnel, underground working, caisson or cofferdam is to be constructed, the notice of project must confirm that drawings for all temporary and permanent ground support will be available on site for the duration of the project.

Note: Refer to the requirements for an assurance in writing in Part 19 (Electrical Safety) if the project will require workers, materials, equipment or machinery to come into proximity to an energized overhead high voltage electrical conductor or other exposed electrical equipment.

20.3 Coordination of multiple employer workplaces

(1) If a construction project involves the work of 2 or more employers or their workers, each employer must notify the owner, or the person engaged by the owner to be the prime contractor, in advance of any undertaking likely to create a hazard for a worker of another employer.

(2) If a work location has overlapping or adjoining work activities of 2 or more employers that create a hazard to workers, and the combined workforce at the workplace is more than 5,

(a) the owner, or if the owner engages another person to be the prime contractor, then that person must

(i) appoint a qualified coordinator for the purpose of ensuring the coordination of health and safety activities for the location, and

(ii) provide up-to-date information as specified in subsection (4), readily available on site, and

(b) each employer must give the coordinator appointed under paragraph (a)(i) the name of a qualified person designated to be responsible for that employer's site health and safety activities.

(3) The duties of the qualified coordinator appointed under paragraph (2)(a)(i) include

(a) informing employers and workers of the hazards created, and

(b) ensuring that the hazards are addressed throughout the duration of the work activities.

(4) The information required by subsection (2)(a)(ii) includes

(a) the name of the qualified coordinator appointed under subsection (2)(a)(i),

(b) a site drawing, which must be posted, showing project layout, first aid location, emergency transportation provisions, and the evacuation marshalling station, and

(c) a set of construction procedures designed to protect the health and safety of workers at the workplace, developed in accordance with the requirements of this Regulation.

Note: The information required by subsection (4) is a part of the overall health and safety program required by Part 3 of this Regulation (Rights and Responsibilities). See sections 118 and 119 of Part 3 of the Workers Compensation Act for the statutory requirements for coordination at multiple employer workplaces and the general duties of owners.

Safe Work Areas and Safe Access

20.4 Safe access

(1) Where practicable, suitable ladders, work platforms and scaffolds meeting the requirements of Part 13 (Ladders, Scaffold and Temporary Work Platforms) must be provided for and used by a worker for activities requiring positioning at elevations above a floor or grade.

(2) There must be suitable access for the safe delivery of equipment and materials to locations in the workplace where they will be used.

[Enacted by B.C. Reg. 420/2004, effective January 1, 2005.]

[Amended by B.C. Reg. 243/2006, effective January 1, 2007.]

20.5 Temporary floors

(1) During the erection of a building or structure of skeleton construction, a temporary floor, decking or formwork must be installed at the main working level where work is being done.

(2) If compliance with subsection (1) is not practicable, a temporary floor or other effective means of protection must be installed not more than two levels or 8 m (25 ft) below the main working level.

(3) Subsections (1) and (2) do not apply during the initial connection of structural members where it is not practicable to provide a floor or decking.

(4) There must be a safe means of access and egress to each main working level referred to in subsection (1).

(5) A stairway comprised of at least framing, treads and a handrail must be provided to each floor level before construction of the next floor or deck surface is undertaken, and the treads on the stairway must not create a tripping or slipping hazard.

20.6 Design loads

(1) A temporary floor, decking, floor opening cover or formwork must be

(a) capable of supporting a uniformly distributed live load of at least 2 kPa (40 psf), or

(b) designed and installed in accordance with the written instructions of a professional engineer if the anticipated live load will be different than 2 kPa (40 psf) in which case a copy of the engineer's plan and specifications must be available at the workplace.

(2) Workers delivering materials to or working on a temporary floor, decking, floor opening cover or formwork must be aware of the safe carrying capacity of the surface and of precautions necessary to prevent overloading.

20.7 Fall protection

Repealed. [B.C. Reg. 420/2004, effective January 1, 2005.]

20.8 Floor and roof openings

Repealed. [B.C. Reg. 312/2003, effective October 29, 2003.]

* See section 4.59 and Part 11 (Fall Protection) of the OHS Regulation.

20.9 Protection from falling materials

(1) If falling material could endanger workers

(a) the danger area must be barricaded or effectively guarded to prevent entry by workers, and conspicuous warning signs must be displayed on all sides and approaches, or

(b) adequate protective canopies must be installed over the danger area, or

(2) Temporary washroom facilities, offices and similar structures on a construction site must be

(a) located outside areas where there is the potential of being hit by falling materials, or

(b) covered by adequate protective canopies.

(3) Protective canopies must be designed and constructed to safely support all loads that may reasonably be expected to be applied to them, but in no case less than 2.4 kPa (50 psf).

20.10 Chutes

(1) Chutes must be provided if the free fall of materials or debris being removed exceeds 6 m (20 ft).

(2) Vertical chutes must be completely enclosed and have gates at each point of entry.

(3) The discharge area of a chute must be barricaded or effectively guarded to prevent workers being injured by falling or flying debris and conspicuous signs must be posted near chute outlets to warn of the danger.

20.11 Safety headgear

Repealed. [B.C. Reg. 312/2003, effective October 29, 2003.]

* See section 8.11 of the OHS Regulation.

20.12 Glass panels

Glass panels installed during construction or alterations must be marked to clearly indicate their presence or effectively guarded at the time of installation.

20.13 Thrust-out crane landing platforms

(1) A professional engineer must certify each thrust-out crane landing platform and certify that the building structure can adequately support loads to be imposed by use of the platform.

(2) Thrust-out crane landing platform drawings and certification must be available on site when the platform is in place.

(3) The rated capacity of a thrust-out crane landing platform must be clearly marked on the platform and not be exceeded.

(3.1) Control measures acceptable to the Board must be implemented to ensure all loads placed on a thrust-out crane landing platform

(a) are safely supported, and

(b) can be safely attached to and detached from the rigging.

(4) Thrust-out platform decking and supporting members must be designed to safely support any concentrated loads that may be landed.

(5) Repealed. [B.C. Reg. 420/2004, effective January 1, 2005.]

[Amended by B.C. Reg. 420/2004, effective January 1, 2005.]

[Amended by B.C. Reg. 19/2006, effective May 17, 2006.]

20.14 Temporary support

During the erection or dismantling of a structure or equipment the employer must ensure that all partially assembled structures or components are supported as necessary to safely withstand any loads likely to be imposed on them.

Bridges and Similar Structures

20.15 Drawings and special procedures

During the construction of a bridge or a structure involving erection of skeleton structural members, documentation of all construction details that require engineering, including erection procedures, temporary bracing and falsework must be

(a) available at the worksite at all times during such work, and

(b) updated as necessary to show changes in details or site conditions, and each update must be certified by a professional engineer.

20.16 Walkways

A worker must not walk upon the surfaces of structural members that have shear connectors, dowels or other protrusions unless suitable walkways and runways are provided to eliminate the tripping hazard.

Concrete Formwork and Falsework

20.17 Specifications and plans

(1) The employer must ensure that a set of plans and specifications meeting the requirements of CSA Standard S269.1-1975, Falsework for Construction Purposes and CSA Standard CAN/CSA-S269.3-M92, Concrete Formwork is prepared for the formwork for each job and for all items of concrete work, the failure of which could cause injury.

(2) Erection drawings and supplementary instructions for concrete formwork, falsework and reshoring must be certified by a professional engineer and available at the site during erection, use and removal of the concrete formwork, falsework and reshoring.

(3) The following types of concrete formwork require erection drawings and supplementary information certified by a professional engineer:

(a) flyforms;

(b) gang forms;

(d) vertical slip forms;

(e) formwork more than 4 m (13 ft) in height;

(f) suspended forms for slabs, stairs and landings;

(g) beam forms;

(h) single sided forms over 2 m (6.5 ft) in height;

(i) cantilever forms;

(j) bridge deck forms;

(k) shaft lining forms;

(l) tunnel lining forms;

(m) forms so designated by the designer of the structure.

[Amended by B.C. Reg. 312/2003, effective October 29, 2003.]

* See also section 4.4 of the OHS Regulation.

20.18 Supervision

(1) A qualified supervisor experienced in the construction of temporary support structures must supervise the erection and use of formwork and falsework.

(2) Workers must be properly instructed on the hazards that they may be exposed to and on the precautions to be taken while around or on formwork and falsework.

[Amended by B.C. Reg. 312/2003, effective October 29, 2003.]

* See also section 117 of the Workers Compensation Act.

20.19 Erection drawing information

(1) Erection drawings and supplementary instructions must clearly show all information necessary to accurately and safely assemble the concrete formwork, falsework and reshoring to the design requirements.

(2) The documents required by subsection (1) must include at least

(a) erection drawings showing sufficient plan and section views and connection details, enlarged where necessary, to clearly describe the formwork and permit accurate assembly,

(b) the quality and grade of materials to be used for the components and their connection,

(d) the load bearing capacity required of the material upon which the sills are to be placed and, where necessary, details of procedures to be used to develop and maintain the required capacity,

(e) the minimum dimensions of sills or other foundation members,

(f) construction, erection and dismantling procedures which require special attention including, where applicable, handling multi-use formwork panels,

(g) details of supports necessary to maintain lateral stability and resist sidesway and racking, specifying the materials, dimensions and locations of external braces, ties, and other support devices,

(h) where structural components connect together, the connections detailed to prevent accidental displacement or rotation of the components,

(i) the reshore plan where applicable,

(j) details of the form or mould into which concrete will be placed,

(k) sufficient load and deflection information to permit a professional engineer to understand the design of the concrete formwork and falsework,

(l) the requirement for outstanding field design and detailing where applicable, and

(m) the sequence, method and rate of load placement to prevent overloading of any part of the formwork.

20.20 Responsibility for design

(1) A professional engineer must be responsible for all field designs, details and changes including the effect they may have on the original design.

(2) Field designs and changes must be documented as required by section 20.19 and must be available at the site before and during placement of concrete or other significant loading of the formwork or falsework.

20.21 Continuity of engineering

The employer, or if the formwork affects workers of more than one employer, the owner or principal contractor, must ensure continuity of design, construction and inspection in the event of a change of professional engineers, or if the separate work of 2 or more professional engineers is involved.

20.22 Equipment requirements

(1) Equipment, materials and hardware which cannot be identified as meeting the standards specified in the professional engineer's drawings and specifications must not be used.

(2) Repealed. [B.C. Reg. 312/2003, effective October 29, 2003.]

* See section 4.3 of the OHS Regulation.

20.23 Concrete placing hazards

(1) Protruding ends of reinforcing steel which are hazardous to workers must be removed or effectively guarded.

(2) If a worker is required to be underneath the formwork during a concrete pour or placement of another significant load, the worker must be restricted from the areas where the loads are placed.

(3) If loads such as bundles of reinforcing steel are being placed on the formwork, or if concrete has just been placed on the formwork, workers must be restricted from the area under those portions of the formwork until it can be assured that the formwork will withstand the load.

(4) Placement of concrete or other loads must stop if any weakness, undue settlement or excess distortion of formwork of a type listed in section 20.17(3) occurs, and may only restart after the formwork has been repaired or strengthened as specified by a professional engineer.

(5) Loads must not be applied to uncured concrete structures except as permitted by the erection drawings and supplementary instructions.

Note: For the purposes of compliance with subsection (1) reinforcing steel may be bent back so as not to be a hazard to workers unless it presents a tripping hazard on a surface where workers would walk.

20.24 Flyform drawings

(1) Erection drawings must be detailed to show

(a) a plan view, a longitudinal section, and a cross section for each type of flyform panel, and

(b) the weight, the calculated position of the centre of gravity and the position of the pickup points for each type of flyform panel.

(2) The design on the erection drawings and supplementary instructions for a flyform panel must provide that as soon as a flyform panel is landed on a supporting surface, before anyone climbs or walks on the panel, and before reinforcing steel or concrete is placed on the panel, the panel must

(a) be able to resist a minimum horizontal load of 3.6 kN (800 lbs) applied in any direction on the top edge,

(b) have a minimum safety factor against overturning about any possible axis of

(i) 1.6 when dead load plus most severe live load configuration plus horizontal loads are considered, and

(ii) 2.0 when dead load plus most severe live load configuration or dead load plus horizontal loads are considered,

(d) have flyform legs placed as necessary to attain the required safety factor against overturning.

(3) If any of the requirements of subsection (2) cannot be obtained for a panel, the panel must, before being unhooked from the crane or hoist, be secured to the permanent structure or an adjacent panel in a manner specified by the formwork designer.

(4) When all flyform panels have been assembled to form a continuous piece of concrete formwork, the concrete formwork and falsework must meet the requirements of section 20.17(1).

20.25 Flyform handling

(1) The erection drawings and supplementary instructions for flyforms must show a step by step procedure for all phases of each cycle of assembly, flying, use, dismantling, and reuse of each flyform panel, including special procedures for non-typical floors.

(2) If any flyform panel is not inherently stable for all possible conditions of load, special notation on the flyform design documents must draw attention to the procedure for obtaining stability.

(3) The erection drawings and supplementary instructions required by subsections (1) and (2), including special procedures required for non-typical floors, must be made available to workers involved in any part of the assembly, flying, use, dismantling and reuse of each flyform panel.

20.26 Inspections

(1) Immediately before placement of concrete or other intended loading, the employer must ensure that the concrete formwork and falsework is inspected and an engineering certificate is issued by a professional engineer, which

(a) indicates the specific areas inspected,

(b) certifies that the concrete formwork and falsework has been erected in accordance with the latest approved erection drawings and supplementary instructions, and

(2) The certificate required by subsection (1) must be available at the site for inspection by an officer.

(3) If a gangform is being reused on the same jobsite without modification, an inspection by a qualified person must be performed before each pour, in which case a new professional engineer's inspection certificate under subsection (1) is not required.

Concrete Pumping

20.27 Equipment identification

(1) A concrete pump, placing boom and mast must bear a legible identification plate specifying

(a) the manufacturer's name,

(b) the year of manufacture,

(d) the maximum pressure the concrete pump can generate.

(2) A concrete placing boom or mast not affixed to a concrete pump must bear an identification plate specifying

(a) the manufacturer's name,

(b) the model and serial number,

(d) the maximum allowable pipe diameter and permitted wall thickness.

20.28 Manufacturer's manual

The manufacturer's operation and maintenance manual for a concrete pump, placing boom and mast must be readily accessible to the operator and to maintenance personnel.

20.29 Inspection and maintenance records

Records of inspection and maintenance as required by Part 4 (General Conditions) must be made by the equipment operator and other persons inspecting and maintaining a concrete placing boom or mast.

20.30 Pre-use inspection

(1) The operator must inspect a concrete placing boom or mast and test its safety and control devices before use on each shift and record the results of the inspection and tests in accordance with section 20.29.

(2) Any defects found in the concrete placing boom or mast must be recorded according to section 20.29 and reported immediately to the supervisor or employer, who must determine the course of action.

(3) If a defect may affect the safe operation of the concrete placing boom or mast, the equipment must not be used until the defect has been remedied.

20.31 Controls

Controls for a concrete placing boom or mast must have their function clearly identified.

20.32 Hydraulic cylinders

(1) Hydraulic cylinders on a concrete pump, placing boom and mast must have pressure relief valves to prevent cylinder and boom damage due to excess pressure.

(2) Hydraulic holding valves must be used on a placing boom or mast if hydraulic hose or coupling failure could result in uncontrolled movement of mechanisms.

20.33 Marking weight

A trailer or skid mounted concrete pump must have a permanent, legible notice stating the total weight of the unit.

20.34 Lifting a pump

A concrete pump may only be lifted using the lift points specified by the manufacturer or a professional engineer.

20.35 Securing a pump

The trailer or skid on which a concrete pump is mounted must be secured to prevent movement during pumping.

20.36 Emergency shutoff

A concrete pump must have a clearly labelled emergency stop switch near the hopper which if activated will stop the pumping action.

20.37 Agitator guarding

(1) Concrete pump agitator guarding must be maintained to the pump manufacturer's specifications, with reasonable allowance for wear.

(2) Bent bars in a concrete pump agitator grill guard must be repaired.

(3) Concrete pump grill bar spacing may be increased to a maximum bar spacing of 8 cm (3 1/4 in) when pumping concrete mixes with a slump of 5 cm (2 in) or less and provided specific instructions are given to the crew regarding the hazard present due to the larger openings in the grill guard.

(4) The distance from the grill bars to the concrete pump's agitator must be at least 7.5 cm (3 in).

(5) A concrete pump agitator grill guard must be hinged or bolted in place.

(6) A person must not stand on the grill when the concrete pump or agitator is running.

20.38 Engine exhaust

A concrete pump's engine exhaust system must be arranged to prevent exhaust exposure to the operator and hopper area.

20.39 Housekeeping

The deck area of a concrete pump must be kept clean and free of unnecessary objects.

20.40 Outriggers

(1) Outriggers must be used in accordance with the concrete placing boom or mast manufacturer's specifications.

(2) Extendible outriggers for a concrete placing boom or mast must be marked to indicate maximum extension.

(3) A concrete placing boom or mast manufactured after January 1, 1999 must have its outriggers or jacks permanently marked to indicate the maximum load they will transmit to the ground.

20.41 Use of a placing boom

(1) Repealed. [B.C. Reg. 312/2003, effective October 29, 2003.]

(2) Repealed. [B.C. Reg. 312/2003, effective October 29, 2003.]

(3) A concrete placing boom or mast must not be used to drag hoses or other loads.

[Amended by B.C. Reg. 312/2003, effective October 29, 2003.]

* See also section 4.3 of the OHS Regulation.

20.42 Pipe diameter and thickness

(1) Repealed. [B.C. Reg. 312/2003, effective October 29, 2003.]

(2) The wall thickness of pipe mounted on a concrete placing boom or mast must be sufficient to withstand a pressure greater than the maximum pressure that the concrete pump can produce in the concrete being pumped.

(3) Pipe sections must be replaced when thickness measurements indicate that wall thickness has been reduced to the limits specified by the manufacturer.

[Amended by B.C. Reg. 312/2003, effective October 29, 2003.]

* See also section 4.3 of the OHS Regulation.

20.43 Pipe clamps

(1) Concrete must not be pumped through pipe with grooved ends, such as those for Victaulic-type couplers.

(2) Pipe clamps used with pipe carrying concrete must have a pressure rating at least equal to the pipe pressure rating.

(3) To ensure proper connection of concrete delivery pipes, pipe and pipe clamp contact surfaces must be free of concrete and other foreign matter when a connection is being made.

(4) Quick connect clamps used on a concrete delivery pipe must be pinned or secured after installation to keep them from inadvertently opening.

20.44 Delivery pipe

Delivery pipe between the concrete pump and the placing system must be supported and anchored to prevent movement and excessive loading on pipe clamps.

20.45 Restraining devices

Restraining devices providing a safety factor of at least 5 must be used on attachments suspended from the placing boom or mast tip.

20.46 Concrete pump lines

(1) Concrete pump discharge line couplings, if located where inadvertent disconnection could cause injury to workers, must be guarded.

(2) The guards on a discharge line coupling must be positioned to effectively deflect in a safe direction any jet of concrete which might result from disconnection of the coupling.

20.47 Equipment inspection

A concrete placing boom and mast must be inspected in accordance with good engineering practice at intervals not exceeding 12 months, repaired as necessary, and certified safe for use by a professional engineer, the manufacturer or the manufacturer's authorized agent.

20.48 Repair certification

Replacement parts used for repair of a concrete placing boom or mast must meet or exceed the original manufacturer's specifications or be certified by a professional engineer.

20.49 Boom and mast weight

The weight of each removable section of a concrete placing boom or mast must be permanently and legibly marked on the section.

20.50 Restriction on use

A concrete placing boom or mast must not be used to hoist loads.

20.51 Compressed air cleaning

(1) A concrete delivery pipe system other than an individual section of pipe may be cleaned out using compressed air, but the system must be securely anchored before such cleaning is done.

(2) Any flexible discharge hose must be removed before cleaning out concrete delivery pipes using compressed air.

(3) Only workers essential to the clean out process may be in the vicinity of concrete delivery pipes when they are pressurized with air.

(4) An air system being used to clean out concrete delivery pipes must have a shutoff valve.

(5) A trap basket must be attached to the discharge end of the concrete delivery pipe to receive the clean out ball or go-devil.

(6) A blowout cap must have a bleed valve to relieve air pressure in a delivery pipe being cleaned using compressed air.

(7) Delivery pipes must be depressurized before clamps and fittings are released.

20.52 Operator's duties

The operator of a concrete placing boom or mast must have full control of the pump and placing equipment controls whenever the equipment is operating and engage in no other duties while operating the concrete pump and placing boom or mast.

20.53 Work near powerlines

Repealed. [B.C. Reg. 312/2003, effective October 29, 2003.]

* See section 19.24 of the OHS Regulation.

20.54 Hopper signal device

If a concrete placing boom operator cannot see and monitor the hopper on the concrete pump from every location the operator must be at during the pumping activity, there must be a device at the hopper for the concrete delivery truck driver and other workers to signal the pump operator if there is a problem at the pump or hopper.

Tilt-Up Building Construction

20.55 Specifications and plans

(1) Before a tilt-up project begins the employer must ensure that a comprehensive set of plans and specifications is prepared, detailing

(a) all erection and bracing procedures,

(b) the type, size and location of all lifting inserts, brace inserts, braces, fittings and anchors for each panel,

(d) the design wind pressure used to determine temporary bracing requirements,

(e) the wind gust speed above which the site must be cleared of workers when panels are supported by the temporary bracing,

(f) the requirements for supplementary reinforcing steel, strongbacks, or other reinforcement to be used during panel erection,

(g) the method of rigging for lifting and handling each panel,

(h) procedures for unique job conditions such as the method of temporary storage on site, and

(i) the weight of each panel.

(2) The plans and specifications for tilt-up panel erection and bracing must be certified by a professional engineer.

(3) Any change to the plans and specifications required by subsection (1), including the use of alternate accessories or erection and rigging procedures, must

(a) provide at least the same margin of safety as required by the original design and specifications, and

(b) be detailed on the documents and be certified by a professional engineer before it is carried out.

(4) One set of up-to-date certified plans and specifications must be maintained on site during lifting and as long as bracing is required to be in place, and the documents must be available for inspection by an officer.

20.56 Design requirements

(1) The plans and specifications for tilt-up panel erection and bracing must ensure that the load to be imposed on each lifting and bracing insert and anchor during panel lifting, moving and bracing will not exceed

(a) if a working load limit for the insert or anchor is not specified by the manufacturer, a maximum working load on the component determined by dividing the manufacturer's guaranteed minimum failure load by the applicable safety factor required by subsection (2) or (3), or

(b) if the working load limit or the manufacturer's guaranteed minimum failure load is not available, a maximum working load determined by calculating the ultimate load capacity in accordance with accepted engineering practice and the BC Building Code, and dividing this value by the applicable safety factor required by subsection (2) or (3).

(2) The minimum safety factor for cast-in lifting inserts is 2.5 except as provided in subsection 20.57(5); and for lift-points secured by drilled-in anchors, the minimum safety factor is 4.0.

(3) The minimum safety factors for bracing components are

(a) 1.67 for braces, and for the uplift or sliding of an anchor slab,

(b) 2.0 for cast-in brace inserts, and

(4) The number of lift inserts for a panel must not be less than the total weight of the panel divided by the working load limit for the inserts in pullout and in shear.

(5) The temporary bracing for a tilt-up panel must be designed to resist the greater of

(a) an unfactored design wind pressure of 700 Pa (15 psf), or

(b) wind pressure calculated in accordance with the BC Building Code based on the probability of 1 in 10 of being exceeded in any year, as listed in the Supplement to the National Building Code of Canada 1990 or as otherwise specified by the local building authority, multiplied by a pressure coefficient of 1.5.

[Amended by B.C. Reg. 312/2003, effective October 29, 2003.]

* See also section 4.3 of the OHS Regulation.

20.57 Panel handling

(1) Tilt-up panel lifting and bracing operations must be done under the direct supervision of a qualified person.

(2) Tilt-up panel lifting must not start until the specified minimum concrete strength has been achieved, as verified through testing in a manner acceptable to the professional engineer responsible for the lifting and bracing design.

(3) A suitable bond breaker must be used to minimize adhesion of each tilt-up panel to the casting surface and wedges and pry bars must be used to assist in releasing the panel from the casting surface.

(4) Crane positions must, where practicable, be chosen to avoid blind lifts.

(5) If a blind lift is necessary, the crane must be located so that if a lift component fails the tilt-up panel will not contact the crane, and if such a crane position is not possible, the safety factor for the lifting inserts must be at least 4.0.

(6) Workers are not permitted in the danger area of the downside face of a tilt-up panel until all bracing components for the panel have been installed.

(7) If bracing or other attachments are required on the downside face of a tilt-up panel, they may only be installed after the panel is erect and is temporarily braced from the upside face as specified in the erection procedures.

(8) All specified tilt-up panel bracing including knee braces and any welded connection specified for temporary support must be installed as detailed before the hoisting rigging is slackened.

(9) Cross-lacing of knee bracing may be done after the hoisting rigging is disconnected but must be no more than one panel behind the lifting process.

(10) All specified bracing must be installed on erected tilt-up panels before leaving the site at the end of the work day.

(11) Drilled-in expansion bolts may only be used to secure braces if specifically authorized by the engineer responsible for the lift and bracing design.

(12) Tilt-up panel lifting must not be done if wind gust velocities exceed 55 km/h (35 mph).

(13) The job site and areas adjacent to braced tilt-up panels must be cleared of personnel if wind gust velocities exceed 100 km/h (60 mph).

20.58 Inspections

(1) The professional engineer who certified the erection procedure or the engineer's designated representative must inspect the site prior to the start of tilt-up panel lifting to ensure that lift procedures and temporary bracing requirements are understood, and a follow-up inspection must occur on the last day of tilt-up panel lifting to ensure that temporary bracing requirements have been met.

(2) Following each inspection required by subsection (1) the person inspecting must issue an inspection report addressing the matters specified in subsection (1) and a copy of the report must be maintained at the site while the temporary bracing system is in place.

(3) Work must not proceed on tilt-up panel lifting or in proximity to panels which have been temporarily braced until the relevant requirements of subsections (1) and (2) have been met.

20.59 Brace removal

The temporary bracing installed to support tilt-up panels must not be removed until the structural design engineer for the building provides a written statement that the tilt-up panels have been adequately connected into the overall structure and the temporary bracing is no longer needed.

Concrete Pre-Stressing and Post-Tensioning

20.60 General requirements

(1) Concrete pre-stressing and post-tensioning operations must be done according to the specifications and instructions of a professional engineer, and a copy of such information must be available on site while the work is being done.

(2) Stressing operations must be carried out under the direction of a qualified supervisor.

(3) Workers involved in pre-stressing or post-tensioning must be instructed in and follow safe work procedures.

(4) Appropriate eye protection must be worn by all workers involved in grouting, stressing and cable trimming operations.

(5) Tendons, including bars, strands and wires, used for tensioning purposes must be protected against physical damage and corrosion during handling, transportation and storage.

(6) Strand couplers must not be reused until they have been inspected by a qualified person and determined to be safe for reuse.

(7) Welding, burning or other work must not be permitted on any surface where strands have been strung or tensioned unless proper care is taken to protect the strands from sparks or other heat sources and from stray electric currents.

20.61 Signalling devices and restricted areas

(1) Visual or audible signalling devices, or both must be provided and used in the area of tensioning operations to warn workers approaching the area.

(2) Workers not directly involved in tensioning or detensioning operations must be kept clear of the danger area and must remain clear until operations are completed and the visual and/or audible signals specified in subsection (1) are turned off or removed.

20.62 Strand measuring

Strand elongation and strand deflection must be measured by a means which does not expose the worker to a risk of injury.

20.63 Guarding during pre-stressing operations

(1) During pre-stressing operations workers must be protected by guards or other suitable devices at the tensioning ends and anchoring points to contain the flying strands and the strand vises in the event of strand failure.

(2) Guards must be fabricated from mild steel plate, not less than 6 mm (1/4 in) thick, or steel mesh with openings 25 mm x 25 mm (1 in x 1 in) or less that provides at least equivalent strength.

20.64 Deflecting devices

Deflecting devices must be designed to prevent slipout and to allow backing off of strands from the deflected position.

20.65 Detensioning and strand cutting procedures

(1) Written detensioning procedures must be prepared by a professional engineer and followed so that workers are not exposed to danger from equipment or strand failure or structural failure.

(2) Written procedures must be developed and implemented to safeguard the operator and other workers from hazards while cutting strands.

20.66 Strand vises and hydraulic devices

(1) Repealed. [B.C. Reg. 312/2003, effective October 29, 2003.]

* See section 4.3 of the OHS Regulation.

(2) Strand vises must not be reused until they have been inspected by a qualified person and determined to be safe for reuse.

(3) Damaged or worn vises and hydraulic equipment must be removed from service.

(4) The supervisor must ensure that operators are given the maximum allowable values for both stretch of the tendon and hydraulic pressure at the pump.

(5) If there is a significant difference between the expected value and the measured value for either stretch of a tendon or hydraulic pressure at the pump, the workers must stop operations on that particular tendon and consult with the professional engineer in charge to obtain instructions on how to proceed.

(6) Each jack pressure gauge must be checked at frequent intervals against a master gauge, and the site engineer must be furnished with a calibration chart.

20.67 Hydraulic equipment

(1) Only hydraulic pressure hoses with self-seating couplings may be used, and care must be taken to ensure that end connections are not subjected to bending stresses at any time.

(2) Hydraulic equipment must have a bypass valve which is adjusted and maintained to limit the hydraulic pressure so that the tension exerted by the jack on the tendon does not exceed 90% of the minimum specified ultimate strength of the tendon.

(3) Hydraulic hoses must be inspected for flaws, leaks or bubbles after each stressing operation, and any damaged hoses immediately removed from service.

(4) The hydraulic system must be regularly inspected for oil leaks and other damage and necessary corrective action taken.

20.68 Platform width

Where adequate clearance exists, the platform width at jacking locations must be at least 80 cm (32 in).

20.69 Blowouts

(1) Each blowout must be reported to the structural design engineer, investigated and logged.

(2) A copy of the logged entry must be available on site for reference purposes.

20.70 Tendon handling

If there is risk of injury from handling coiled post-tensioning tendons a suitable coil handling device must be used.

20.71 Securing jacks

All jacks must be secured to suitable anchors before they are installed on a cable for tensioning, and must not be unsecured before they are removed from the cable, if a falling jack could endanger workers.

Open Web Joists and Trusses

20.72 Erection instructions

(1) Work must not be undertaken on the erection of premanufactured open web joists and trusses until clear and appropriate written instructions from a professional engineer or the manufacturer of the joists or trusses, detailing safe erection procedures, are available at the worksite.

(2) Erection and temporary bracing of open web joists and trusses must be done in accordance with the written instructions required by subsection (1).

Roof Work

20.73 Fall protection

Repealed. [B.C. Reg. 420/2004, effective January 1, 2005.]

20.74 Crawl boards and ladders

(1) Crawl boards or ladders used for roof work must be securely fastened over the ridge of the roof, or must be otherwise effectively anchored.

(2) The use of an eavestrough to support a crawl board or ladder on a roof is prohibited.

20.75 Steep roof requirements

If a worker is employed on a roof having a slope ratio of 8 vertical to 12 horizontal or greater, the worker must use a personal fall protection system or personnel safety nets must be used, and 38 mm x 140 mm (2 in x 6 in nominal) toe-holds must be used if the roofing material allows for it.

Note: Exposed horizontal roof strapping may be used as toe-holds as long as it provides safe footing.

20.76 Chutes and hoists

The roof edge about a chute, bitumen spout and material hoist must have guardrails meeting the requirements of Part 4 (General Conditions) or barriers of at least equivalent strength to at least 2 m (6.5 ft) on each side of such a work area.

20.77 Mechanical equipment

Mechanical or powered equipment which has the potential to push or pull a worker over an unguarded edge must not be used unless operated according to procedures acceptable to the Board.

[Amended by B.C. Reg. 312/2003, effective October 29, 2003.]

* See also section 4.3 of the OHS Regulation.

Excavations

20.78 Work standards

(1) Excavation work must be in accordance with the written instructions of a professional engineer if

(a) the excavation is more than 6 m (20 ft) deep,

(b) support structures other than as specified in section 20.81 are used in the excavation,

(d) the excavation is subject to vibration or hydrostatic pressure likely to result in ground movement hazardous to workers, or

(e) the ground slopes away from the edge of the excavation at an angle steeper than 3 horizontal to 1 vertical.

(2) The written instructions required in subsection (1) must

(a) be certified by a professional engineer,

(b) be available at the site, and

[Amended by B.C. Reg. 253/2001, effective January 28, 2002.]

20.79 Underground utilities

(1) Before excavating or drilling with powered tools and equipment, the location of all underground utility services in the area must be accurately determined, and any danger to workers from the services must be controlled.

(2) Excavation or drilling work in proximity to an underground service must be undertaken in conformity with the requirements of the owner of the service.

(3) Pointed tools must not be used to probe for underground gas and electrical services.

(4) Powered equipment used for excavating must be operated so as to avoid damage to underground utility services, or danger to workers.

[Amended by B.C. Reg. 312/2003, effective October 29, 2003.]

* Statutes or regulations covered by other jurisdictions apply to excavation or drilling in proximity to an underground service.

20.80 Removing nearby hazards

Trees, utility poles, rocks and similar objects adjacent to an area to be excavated must be removed or secured if they could endanger workers.

20.81 Sloping and shoring requirements

(1) Before a worker enters any excavation over 1.2 m (4 ft) in depth or, while in the excavation, approaches closer to the side or bank than a distance equal to the depth of the excavation, the employer must ensure that the excavation sides are sloped or supported as specified by a professional engineer, or that the sides of the excavation are

(a) sloped at angles, dependent on soil conditions, which will ensure stable faces, but in no case may the slope or combination of vertical cut and sloping exceed that shown in Figure 20-1,

(b) benched as shown in Figure 20-2,

(d) supported by manufactured or prefabricated trench boxes or shoring cages, or other effective means.

(2) If the end of a trench over 1.2 m (4 ft) in depth is not adequately sloped, end shoring must be installed unless

(a) a worker in the trench is not required to approach closer to the end of the trench than a distance equal to the depth of the trench at that end,

(b) where, for the prevailing soil conditions at the end of the trench, the permissible spacing of uprights equals or exceeds the width of the trench, or

(3) If end shoring is required, the walers for the end shoring must be installed to bear against the walers that extend along the sides of the trench, or in a manner that will provide equivalent structural restraint.

(4) End shoring must be designed by a professional engineer if the end shoring waler length exceeds 1.8 m (6 ft).

(5) Shoring must extend from at least 30 cm (1 ft) above ground level to as close to the bottom of the trench as the material being installed will allow, but in no case more than 60 cm (2 ft) from the bottom.

(6) Shoring need not extend above ground level where traffic crossing plates need to be used, provided that other measures are taken to prevent excavated or other material from entering the excavation.

[Amended by B.C. Reg. 253/2001, effective January 28, 2002.]

20.82 Timber shoring and grades

(1) Timber shoring materials must be lumber graded Number 2 or better from the following species groups: Douglas fir-larch, hemlock-fir, spruce-pine-fir or coast-Sitka-spruce.

(2) All lumber must be graded to the National Lumber Grades Authority Standard Grading Rules for Canadian Lumber.

[Amended by B.C. Reg. 312/2003, effective October 29, 2003.]

* See also section 4.4 of the OHS Regulation.

20.83 Safe shoring procedures

(1) Shoring materials must be installed from the top down and removed in reverse order.

(2) Workers must not enter an excavation to remove shoring materials if ground conditions have deteriorated so as to make entry for shoring removal unsafe.

(3) Shoring or manufactured or prefabricated support systems must be installed in firm contact with the faces of the excavation, and in a manner which ensures no loss of soil from behind or below the bottom of the shield or shoring while the excavation is open.

(4) Unless otherwise indicated by the manufacturer or a professional engineer, in writing, voids between the shoring and the excavation face must be backfilled or blocked.

20.84 Manufactured shoring

Repealed. [B.C. Reg. 312/2003, effective October 29, 2003.]

* See section 4.3 of the OHS Regulation.

20.85 Trench support structures

(1) Trench support structures, other than those designed by a professional engineer, must comply with Table 20-1 for the following relevant soil conditions:

(2) If Table 20-1 is to be used for a combination of supporting and sloping, the selection of shoring elements must be based on the overall depth of the excavation, and the arrangement must conform to Figure 20-3.

(3) Cross braces and trench jacks must be installed in a horizontal position and must be secured against dislodgment.

(4) The minimum number of cross braces at each cross bracing location is determined by the trench depth as follows:

Depth at location	Number of braces
up to 2.4 m (8 ft)	2
2.4 m to 3.7 m (8 ft to 12 ft)	3
3.7 m to 4.6 m (12 ft to 15 ft)	4
4.6 m to 6 m (15 ft to 20 ft)	5

(5) At each cross bracing location the cross braces must be less than 1.2 m (4 ft) apart, and the uppermost cross brace must be within 60 cm (2 ft) of ground level.

(6) Repealed. [B.C. Reg. 312/2003, effective October 29, 2003.]

* See section 4.3 of the OHS Regulation.

(7) Hydraulic or pneumatic trench jacks must have a means of ensuring that they will not collapse in the event of loss of internal pressure.

(8) Uprights must not spread outwards more than 15 degrees from the vertical when viewed along the trench.

(9) Plywood may be substituted for two inch thick shoring elements provided that

(a) the plywood is not less than 19 mm (3/4 in) thick,

(b) the trench is not over 2.7 m (9 ft) in depth,

(d) cross braces do not bear directly on plywood, and

(e) cross braces bearing on uprights or walers are located at all joints in plywood sheathing.

20.86 Spoil piles

If the average depth of a spoil pile which is adjacent to a supported excavation exceeds 60 cm (2 ft), the selection of the shoring or shielding must take into account the resulting increase in lateral soil pressure.

Note: Table 20-1 includes an allowance for 60 cm (2 ft) of spoil pile adjacent to the excavation. In such cases shoring or shielding will be deemed acceptable if rated adequate for a tabulated depth equal to the depth of the excavation plus the average depth of the spoil pile minus 60 cm (2 ft). For other systems consult the manufacturer's instructions.

20.87 Entry and exit

(1) Safe means of entry and exit must be provided for an excavation a worker enters.

(2) If workers are required to enter a trench over 1.2 m (4 ft) deep, the safe point of entry and exit must be located within 8 m (25 ft) of the workers and the excavation must be safely supported or sloped to the entry and exit location.

(3) Walkways must be secured to prevent dislodgment.

(4) The open side of an access route into an excavation used by mobile equipment must have a curb.

20.88 Guarding

If an excavation is a hazard to workers, it must be effectively covered or guarded.

20.89 Excavation crossings

A walkway across an excavation must be at least 50 cm (20 in) wide, and if crossing an excavation over 1.2 m (4 ft) deep, be equipped with guardrails, meeting the requirements of Part 4 (General Conditions), on both sides.

20.90 Excavated materials

(1) Excavated material must be kept back a minimum distance of 60 cm (2 ft) from the edge of a trench excavation and 1.2 m (4 ft) from any other excavation.

(2) Under no circumstances may excavated material be piled so that it endangers workers.

20.91 Use of skips or buckets

If a skip or bucket is used to remove material from an excavation, horizontal shoring members must be shielded from dislodgment with vertical planking.

20.92 Scaling and trimming

The sides of an excavation must be scaled and trimmed or otherwise stabilized to prevent slides of material or falls of rock which could endanger workers.

20.93 Height limitations

In pits, quarries and similar excavations the height of unstable faces must not exceed the maximum safe reach of the excavating equipment being used.

20.94 Positioning equipment

Whenever possible, power machines excavating banks must be positioned so that the operator is on the side away from the bank and with the boom positioned closest to the side of the excavation.

20.95 Water accumulation

(1) Water must not be allowed to accumulate in an excavation if it might affect the stability of the excavation or might endanger workers.

(2) Erosion of slopes by surface water must be prevented if workers may be endangered.

Table 20-1: Trench support structures

Size and spacing of members¹ (metric figures)
UPRIGHTS			WALERS		CROSS BRACES
Trench depth (m)	Minimum dimen- sions (mm)²	Max- imum spacing (m)	Minimum dimen- sions (mm)²	Max- imum vertical spacing (m)	width of trench (m) Up to 1.8 1.8-3.7 Minimum dimensions (mm)²		Maximum spacing (m)
Trench depth (m)	Minimum dimen- sions (mm)²	Max- imum spacing (m)	Minimum dimen- sions (mm)²	Max- imum vertical spacing (m)	Vert- ical	Hori- zontal
Type A: Hard and solid soil
1.2-3 ³	38 x 235	1.8	89 x 140	1.2	89 x 89	140 x 140	1.2	1.8
3-4.6	38 x 235	1.2	140 x 140	1.2	89 x 140	140 x 191	1.2	1.8
4.6-6	38 x 235	Close tight	140 x 140	1.2	140 x 191	191 x 191	1.2	1.8
Type B: Soil likely to crack or crumble
1.2-3 ³	38 x 235	1.2	89 x 140	1.2	89 x 140	140 x 140	1.2	1.8
3-4.6	38 x 235	0.9	140 x 191	1.2	140 x 140	140 x 191	1.2	1.8
4.6-6	38 x 235	Close tight	140 x 191	1.2	140 x 191	191 x 191	1.2	1.8
Type C: Soft, sandy, filled or loose soil
1.2-3 ³	38 x 235	Close tight	140 x 191	1.2	140 x 140	140 x 191	1.2	1.8
3-4.6	38 x 235	Close tight	191 x 191	1.2	140 x 191	191 x 191	1.2	1.8
4.6-6	64 x 235	Close tight	191 x 241	1.2	140 x 191	191 x 241	1.2	1.8
Size and spacing of members¹ (imperial figures)
UPRIGHT			WALERS		CROSS BRACES
Trench depth (feet)	Minimum dimensions (inches)²	Max- imum spacing (feet)	Minimum dimensions (inches)²	Max- imum vertical spacing (feet)	width of trench (feet) Up to 6 6-12 Minimum dimensions (inches)²		Maximum spacing (feet)
Trench depth (feet)	Minimum dimensions (inches)²	Max- imum spacing (feet)	Minimum dimensions (inches)²	Max- imum vertical spacing (feet)			Vertical	Hori- zontal
Type A: Hard and solid soil
4-10 ³	2 x 10	6	4 x 6 ⁴	4	4 x 4	6 x 6	4	6
10-15	2 x 10	4	6 x 6	4	4 x 6	6 x 8	4	6
15-20	2 x 10	Close tight	6 x 6	4	6 x 8	8 x 8	4	6
Type B: Soil likely to crack or crumble
4-10 ³	2 x 10	4	4 x 6	4	4 x 6	6 x 6	4	6
10-15	2 x 10	3	6 x 8	4	6 x 6	6 x 8	4	6
15-20	2 x 10	Close tight	6 x 8	4	6 x 8	8 x 8	4	6
Type C: Soft, sandy, filled or loose soil
4-10 ³	2 x 10	Close tight	6 x 8	4	6 x 6	6 x 8	4	6
10-15	2 x 10	Close tight	8 x 8	4	6 x 8	8 x 8	4	6

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Part 20 Construction, Excavation and Demolition

Part 20 Contents

GENERAL REQUIREMENTS

SAFE WORK AREAS AND SAFE ACCESS

BRIDGES AND SIMILAR STRUCTURES

CONCRETE FORMWORK AND FALSEWORK

CONCRETE PUMPING

TILT-UP BUILDING CONSTRUCTION

CONCRETE PRE-STRESSING AND POST-TENSIONING

OPEN WEB JOISTS AND TRUSSES

ROOF WORK

EXCAVATIONS

SCALING OPERATIONS

MARINE CONSTRUCTION, PILE DRIVING AND DREDGING

DEMOLITION

WORK IN COMPRESSED AIR

Construction, Excavation and Demolition Definitions

20.1 Definitions

General Requirements

20.1A Qualified contractor

20.2 Notice of project

20.3 Coordination of multiple employer workplaces

Safe Work Areas and Safe Access

20.4 Safe access

20.5 Temporary floors

20.6 Design loads

20.7 Fall protection

20.8 Floor and roof openings

20.9 Protection from falling materials

20.10 Chutes

20.11 Safety headgear

20.12 Glass panels

20.13 Thrust-out crane landing platforms

20.14 Temporary support

Bridges and Similar Structures

20.15 Drawings and special procedures

20.16 Walkways

Concrete Formwork and Falsework

20.17 Specifications and plans

20.18 Supervision

20.19 Erection drawing information

20.20 Responsibility for design

20.21 Continuity of engineering

20.22 Equipment requirements

20.23 Concrete placing hazards

20.24 Flyform drawings

20.25 Flyform handling

20.26 Inspections

Concrete Pumping

20.27 Equipment identification

20.28 Manufacturer's manual

20.29 Inspection and maintenance records

20.30 Pre-use inspection

20.31 Controls

20.32 Hydraulic cylinders

20.33 Marking weight

20.34 Lifting a pump

20.35 Securing a pump

20.36 Emergency shutoff

20.37 Agitator guarding

20.38 Engine exhaust

20.39 Housekeeping

20.40 Outriggers

20.41 Use of a placing boom

20.42 Pipe diameter and thickness

20.43 Pipe clamps

20.44 Delivery pipe

20.45 Restraining devices

20.46 Concrete pump lines

20.47 Equipment inspection

20.48 Repair certification

20.49 Boom and mast weight

20.50 Restriction on use

20.51 Compressed air cleaning

20.52 Operator's duties

20.53 Work near powerlines

20.54 Hopper signal device