Safety Procedure for Erecting and Dismantling Concrete Formwork Systems

This safe work method statement outlines conventional safety requirements for erecting and dismantling the vertical concrete forming systems. However, equipment and forming systems differ for different manufacturers and suppliers. Therefore reference must always be made to the instructions and procedures of the particular manufacturer or supplier whose equipment is being used.

Since field conditions vary and are beyond the control of the publisher, safe and proper use of the formwork equipment is the responsibility of the user and not us. This procedure does not supersede any applicable federal, state or local code, ordinance or regulation.

Safety precautions prescribed by OSHA and other government agencies should be followed at all times and persons working with forming equipment should be equipped with requisite safety devices.

Formwork General Safety Requirements

All form components and/or hardware must be kept clean, and if appropriate, lubricated to insure proper performance and to allow for proper inspection.

All form components must be inspected regularly for damage or excessive wear. Equipment found to be in these conditions must be replaced immediately and not re-used.

Field repair of modular formwork components (other than plywood repairs) must not be undertaken without consulting the manufacturer’s qualified representative.

The forming layout shall be prepared or approved by a person qualified to analyze the loadings and stresses which are induced during the construction process. The layout shall be at the job site.

Forming installation and pouring procedures must comply with safe practices and with the requirements of the law and governmental regulations, codes and ordinances.

Formwork Erection

Do not deviate from layout drawings when erecting formwork without the approval of a qualified designer.

Be certain that all wall ties are in place and secured as per manufacturer’s recommendations. Do not weld, bend or otherwise alter wall ties as it may seriously reduce their strength.

Adequate temporary bracing must be in place while initially setting formwork. Assure that formwork is properly braced and stabilized against wind and other external forces.

Safe working platforms must be installed as per applicable safety standards and as stated in following sections.

When gang forming, lifting devices must be properly spaced and securely attached as per manufacturer’s recommendations. Rigging must be arranged so that any one lifting bracket is not overloaded and that lifting cables are not at excessive angles, which will reduce allowable loads. Spreader beams with load equalizers are recommended for all but simple two point lifts. Follow manufacturer’s/supplier’s recommended procedures concerning capacity and use of lifting hardware and crane.

A minimum of two tag lines must be used to control movement of crane-handled formwork. Do not allow personnel on or directly under any gang form while it is being moved or suspended in air.

Do not erect gang forms when job site wind conditions prevent safe maneuvering of gangs. Assure that all rigging connections are properly made in accordance with safe practices and procedures.

Formwork should be adequately braced, re-anchored, or otherwise secured prior to releasing lifting mechanism.

Wall forms must not be erected so as to support deck concrete loading unless the wall forms are a designed part of the deck support system.

Formwork Bracing Requirements

Aligners (alignment devices, plumbing struts) are considered only as alignment devices with no provisions for withstanding concrete pressure or any portion thereof. Maintain forms plumb during pour to ensure that aligners are not supporting or stabilizing concrete pressures.

Braces used to withstand concrete pressure must be designed by a qualified formwork designer.

Unless specified, wind loading and other external lateral loads are not considered in the manufacturer’s layout drawings.

The adequacy of stakes, dead-men, sills, anchor-bolts, etc., must be determined to assure safe support of the imposed brace loads. The responsibility for adequate anchorage of braces should be assigned only to those personnel with sufficient experience to assure sound judgement.

Before removing braces, assure that the concrete has attained sufficient strength to safely support the imposed load at support locations.

Do not exceed the rated load of the braces.

Inspect installed braces immediately after installation for correctness of spacing and proper attachment device.

Formwork Walkway System Safety Requirements

All walkway systems must be properly positioned, spaced and fastened as per manufacturer’s specifications and all applicable safety regulations.

Walkway systems must be in place along the upper level of formwork. Workers must never attempt to walk or stand on top of forms.

Scaffold brackets must be attached with the manufacturer’s recommended connectors. Never use substitutes or make-shift devices. Never hang brackets from wall ties after removal of forms.

All walkway platforms must utilize at least two (2) planks laid side by side, and must overlap their support ledger by not less than 6 inches. Unsupported ends of scaffold planks must not project more than 12 inches past their support ledger.

Scaffold planks must be minimum 2 inch x 10 inch nominal lumber and must be scaffold grade as recognized by approved grading rules for the species of lumber used, or must be of materials having equivalent or greater strength. Scaffold planks must safely support a minimum of 25 pounds per square foot over a maximum span of 8 feet.

When deemed appropriate by the competent person, scaffold planks must be nailed and clinched, bolted or otherwise positively secured against dislodgement from effects of wind, weather, gang form lifting operations or the like. Bolt heads and nails must be driven flush with tops of planks to prevent tripping hazards.

All scaffold bracket platforms must be equipped with guardrails, midrails and toeboards along all open sides and ends and be maintained secure and in good condition at all times. Guardrails must be of at least 2 x 4 nominal sized lumber, with minimum 1 x 6 or 2 x 4 nominal midrails, with toeboards at least 4 inches high, supported by 2 x 4 nominal lumber uprights spaced not more than 8 feet apart, or must be of other materials providing equivalent or greater strength and protection.

Maximum spacing between scaffold brackets is eight feet. Never exceed this distance unless the walkway system has been specifically designed for a greater distance. Follow manufacturer’s recommendations as to loading and spacing of scaffold brackets. Unless designed otherwise, scaffold brackets are designed to support a maximum load of 25 pounds per square foot when spaced on 8 foot centers. Scaffold brackets are not designed for the additional loads imposed from stacking rebar or placing other equipment on walkways.

Always brace and/or otherwise secure forms and scaffold from overturning due to attachment and use of scaffold brackets.

Never allow persons to work on one level of walkways if others are working directly below or overhead unless proper protection is provided, such as safety nets.

It is unsafe and unlawful for persons to occupy any form walkway while the form is being moved.

Access ladders or other suitable safe methods must be used to obtain access to walkway platforms. Do not position ladders so that their weight while being used can effect the strength or stability of the scaffold and formwork.

Do not use form panels as a ladder.

If using walkway systems is not practical, personnel must be protected against falls by means of personal fall arrest system attached to components having adequate strength to meet or exceed applicable codes or by safety nets or other equivalent protection. Personnel protected by personal fall arrest system must exercise additional care when handling formwork components.

Special Safety Applications for Concrete Formwork

Fasteners for support brackets, friction collars and other friction devices must be pre-tensioned to the manufacturer’s specification during erection and re-checked immediately prior to placing concrete.

Assure that anchor brackets are attached properly and with required thread engagement per manufacturer’s recommendations. The proper anchor bolts and inserts must be used and be of adequate strength for combined shear and tension loadings. Assure that the concrete has attained sufficient strength to properly allow the designed use of these devices with the required safety factors.

Assure that anchor brackets are installed so that they are equally loaded and are installed correctly prior to setting the formwork. Anchor bolts must be tight and brackets level.

When erecting forms for battered walls, allowance must be provided for proper anchorage to resist resulting uplift forces.

Layouts must be prepared by a qualified formwork designer for all one-sided and cantilevered wall forming applications. Ensure that all anchorages and bracing are installed per layout drawings. Follow manufacturer’s recommendations regarding installation and use of anchoring devices.

For all other special applications, for example, jump forms, climbing forms, etc., consult manufacturer.

Formwork Inspection Requirements

Inspect completed formwork prior to placing concrete to assure proper placement and secure connections of ties and associated hardware. All threaded connectors, such as ties, inserts, anchor
bolts, etc., must also be checked for proper thread engagement.

Inspect erected form walkway systems before each use. Assure that bolts, nuts, and other connections are fastened securely.

Inspect bracing attachments and form alignment after each form cycle. Inspect installed forms and braces immediately prior to pour and during pour.

Formwork Concrete Placement Precautions

The contractor must verify prior to and during concrete placing that the method of placement and rate of pour is consistent with formwork design. DO NOT OVERLOAD FORMWORK.

Concrete must not be placed in any manner which imposes impact loads that exceed the rated capacity of the form.

Instruct personnel on proper vibration. Do not use vibrator to move concrete. Do not vibrate further than one-foot into the previous lift. Avoid vibrator contact with wall ties. External vibrators must not be attached to formwork unless it was designed for their use.

Removal / Stripping of Formwork

Follow manufacturer’s recommended field procedures – generally, reverse the order of procedures used in erection of formwork. Be certain that concrete has sufficiently set to carry its own weight and any imposed loads prior to stripping formwork.

When gang-forming, secure the lifting mechanism prior to removal of ties, anchors and/or bracing.

Use extreme caution for all formwork to assure that no panel, walkway bracket, brace or any other form component is unfastened prematurely.

Assure that all disconnects have been made and the bond of the formwork to concrete has been broken prior to lifting of gang form.

Reference:

SCAFFOLDING, SHORING AND FORMING INSTITUTE, INC. 1300 SUMNER AVENUE, CLEVELAND, OHIO 44115