In brief
Serious accidents in formwork come from four directions: formwork collapsing or bursting during pouring, falls from formwork edges or floor openings, materials falling while being moved by crane or struck, and the damage cement does to the skin. The Regulation on OHS in Construction Work requires formwork to be done under the supervision of a competent person, the formwork to be checked before every pour and no one without a task to be present in the striking area.
Formwork safety: what does the regulation require?
In a reinforced concrete building, formwork is a system that temporarily carries the whole load until the day the concrete can support itself. This temporariness is the source of the risk: formwork is erected, altered, loaded and struck every day. Formwork safety is therefore ensured not by a single check but by a separate discipline at every stage from erection to striking.
Part (B) of Annex 4 of the Regulation on Occupational Health and Safety in Construction Work governs formwork and concrete work for outdoor workplaces in separate articles:
| Article | Provision | On-site equivalent |
|---|---|---|
| 81 | In concrete pouring, the position and securing of the pump, spreading the concrete as it is poured, no work under the section being poured, continuous checking of formwork until pouring ends and preventing formwork opening and bursting | A separate person watching the formwork throughout the pour |
| 82 | Formwork is done under the supervision of a competent person appointed by the employer and by experienced employees | The formwork foreman's name and duties in writing |
| 83 | Formwork panels, temporary supports and props are planned, designed, erected and maintained to withstand the loads and stresses placed on them | Prop spacing and bracing according to the plan |
| 84 | Adequate measures are taken against risks arising from the temporary instability of the formwork system | Temporary securing during erection |
| 85 | The adequacy of formwork is checked before every concrete pour; slip, tunnel and table formwork parts are checked before every use, and deformed parts are not used | Pre-pour inspection form |
| 86 | The striking method, sequence, safe access, removal of material and balanced lowering are arranged; no one without a task is present in the striking area | Striking instruction and closing off the area |
For the general obligations of the regulation and the health and safety plan, see our article on the Regulation on OHS in Construction Work.
Formwork collapse: measures at erection
Formwork collapse mostly happens during pouring, at the moment the formwork is most heavily loaded, and affects everyone on and under it. Its roots, however, lie in erection:
- Ground: If props are placed directly on soft or filled ground, the ground settles under the weight of the concrete. A load-spreading base plate is placed under the props, and the ground is checked again after rain.
- Props and bracing: Prop spacing is set according to the formwork system or calculation; extended, inclined, dented or spliced props are not used. On tall props, cross-bracing is fitted in full.
- System formwork: The manufacturer's assembly instructions are followed; parts from different systems are not mixed, and no load is applied until missing pins and locks have been fitted.
- Changes on site: Changes such as cutting openings, removing props or extending formwork are not made without the competent person's approval.
- Temporary stability: After column and wall formwork has been erected, it is secured with push-pull props against wind and impact; this securing is not left off even when erection is left half-finished.
Falls by formwork carpenters and falling materials
Formwork carpenter falls usually happen at the edge of slab formwork, while walking on beams, at stair and lift openings, or when losing balance while positioning a formwork panel. Annex 4 (A) of the regulation gives priority in work at height to collective protection measures such as guardrails, platforms, covers and safety nets; where these are not enough or cannot be applied, it requires a full body harness attached to an anchor point or lifeline. In practice, ensure the following:
- Edge protection or secured covers are installed at slab edges and openings at the same time as the formwork is erected.
- Access to formwork level is by ladder or scaffold, not by climbing formwork elements. Building scaffolds undergo periodic inspection every 6 months; for the tagging system, see our article on building scaffold inspection, and track the dates with the OHS calendar tool.
- Work on column and wall formwork is done from a platform with guardrails.
- The point the harness will be attached to is identified before work starts; for harness selection, see our article on the full body safety harness.
The same regulation sets clear rules for falling materials too: hand tools and materials used at height are prevented from falling, access to areas where objects may fall is prevented, and material is not thrown directly to the ground from any height. When formwork panels are moved by crane, no one works under the load; for crane rules, see our article on tower crane safety, and for the general principles of work at height, our article on what work at height is.
Concrete pouring safety
Concrete pouring safety starts with the check made before the pour begins and continues with uninterrupted monitoring until the pour ends. Under Art. 81 of the regulation, in slab pours where heaping would be dangerous, concrete is poured spread out appropriately; no one works directly under the section being poured; the hose is not allowed to whip, and formwork is checked continuously until the pour ends. If the pump operator cannot see the pouring point, suitable communication is provided.
Before the pour, tick off the following list together with the competent person:
| Checkpoint | What to look at |
|---|---|
| Props and bracing | Spacing according to plan, plumb, complete bracing, firm base |
| Formwork surface and connections | Ties, locks, pins and clamps complete; no gaps or deformation |
| Edge protection | Guardrails or covers in place at slab edges and openings |
| Access | Safe access to the pouring point by ladder or scaffold |
| Below the pour | The area under the section being poured cleared and closed off |
| Pump and mixer | Outriggers on firm ground, safe distance from power lines |
| Monitoring | A person designated to watch the formwork throughout the pour, stop signal known |
| Personal protective equipment | Hard hat, high boots, gloves, goggles |
If noise, deflection or leakage is noticed in the formwork during the pour, pouring is stopped and everyone under the formwork is moved away. This rule should be stated clearly to the team in the toolbox talk before the pour.
Formwork striking
Formwork striking is the reverse of erection but has its own particular risks. The site manager or competent person decides when to strike according to whether the concrete has reached sufficient strength; the team does not decide on its own that "it can come down now". A striking procedure in line with Art. 86 of the regulation includes the following steps:
- Written sequence: Which element will be struck in which order, and which props will be left temporarily, is determined.
- Close off the area: Access to the striking area by anyone without a task is prevented, and passages on the floor below are closed.
- Controlled lowering: Panels and formwork elements are not thrown down; they are lowered in a balanced way by hand or with lifting equipment.
- Deal with nailed material: Nails in struck boards are removed or bent over immediately; material is stacked so it does not block passageways.
- Keep the edge protection: Guardrails and covers removed during striking are put back the same day.
In multi-storey buildings, how long the formwork on lower floors stays supported, and with which props, while upper floors are being poured is also an engineering decision. Striking props early to move them to the upper floor because they are "needed" can leave the lower slab facing a load it cannot yet carry. Which props are to remain in place should be written clearly in the striking instruction.
For the manual handling of heavy panels, the principles in our article on manual handling and lifting technique apply.
Cement and formwork oil: skin risks
Wet concrete and mortar are alkaline. Concrete that soaks trousers when kneeling or gets into boots can cause chemical burns to the skin within hours; often the burn is only noticed once the work is finished. Some components of cement can also cause allergic dermatitis over time; the SGK (Social Security Institution) list of occupational diseases includes cement among the agents causing occupational skin diseases. Formwork oil also irritates the skin with prolonged contact.
The measures are simple but must be applied consistently: waterproof gloves, high boots that concrete cannot get into, waterproof knee pads for kneeling work, changing wet clothing immediately and facilities on site for washing hands and skin with clean water. For symptoms and a skin care plan, see our article on occupational dermatitis.
Common mistakes
- Erecting formwork by eye, not checking prop spacing and bracing against the plan
- Continuing to work under or near the formwork during pouring
- Planning to fit edge guardrails after the formwork work is finished
- Striking without a sequence or closing off the area, and throwing material down
- Not washing skin that has been in contact with wet concrete until the end of the job
On construction sites in Bursa and the surrounding provinces, we follow the formwork and pouring stages through site rounds and pre-pour checks under our OHS specialist service. For other site risks, see our article on the construction site OHS checklist and our construction sector page.
Frequently Asked Questions
Who is the competent person in formwork?
The regulation requires formwork to be done under the supervision of a competent person appointed by the employer and by employees with relevant experience. This person's name, duties and authority should be set out in writing; the pre-pour check and the striking of formwork should be done under their supervision.
When is formwork struck?
The time of striking depends on the concrete reaching a strength at which it can carry its own load and the loads to be placed on it, and is decided by the site manager or competent person. The team does not decide on its own; striking is done according to a written sequence.
What should be done if the formwork makes a noise during pouring?
Pouring is stopped immediately, everyone under and near the formwork is moved away and the competent person checks the formwork. The regulation requires formwork to be checked continuously until the pour ends and formwork opening and bursting to be prevented.
What should be watched for with tunnel formwork?
Art. 85 of the regulation requires parts of tunnel, slip and table formwork such as connections, securing elements, ties, hydraulic hoses, lifting points, jacks and wheel systems to be checked regularly and before every use, and deformed parts not to be used. No one works under the load while it is being moved by crane, and the guardrails of formwork platforms are kept complete.
Does wet concrete harm the skin?
Yes. Wet concrete and mortar are alkaline; prolonged contact with the skin can cause chemical burns and repeated contact can cause dermatitis. Waterproof gloves, high boots and the ability to wash off contact immediately are the basic measures.
A certified specialist matched to your hazard class: site inspections, approved logbook, training plan, annual plan and report follow-up.
Bursa SİSTEMER OSGB Technical Team — written from the field experience of our OHS specialists and workplace physicians. Legal information is valid as of the publication/update date; contact us for an assessment specific to your business.