In brief
During structural work, slab edges, lift shafts, service shafts and stairwells are where the risk of falling is highest. The Regulation on OHS in Construction Work requires temporary edge protection conforming to TS EN 13374 around these openings, a top guardrail of at least 1 metre and a toe board of at least 15 centimetres, and the system to be inspected at least once a week. The real risk is protection being removed during work and not put back; removal must therefore be tied to a permit and record system.
Why is floor opening protection a separate heading?
As the structural work on a building progresses, the same openings repeat on every floor: slab edges, the lift shaft, service shafts, the stairwell, light wells and window openings where frames will later be fitted. Floor opening protection is the collective protection arrangement that prevents people from falling through these openings and materials from falling down them. When people think of working at height on a construction site, scaffolding and harnesses usually come to mind; yet falls through openings happen during ordinary walking or carrying of materials, at moments when people think they are "not working at height".
This article explains covering openings, slab-edge guardrails and the hardest part: how to manage the removal of protection while work is in progress. For the general framework of working at height, see our article on what working at height means, and for a list covering the whole site, our construction site OHS checklist.
What does the legislation require? Collective protection first, then the harness
The basis is the Regulation on Occupational Health and Safety in Construction Work. Annex 4 of the regulation requires safety when working at height to be provided primarily through collective protection measures such as guardrails, fall-prevention platforms, barriers, covers, scaffolds and safety nets. Where collective protection cannot be applied or has to be removed temporarily, personal protection is used: a full body harness together with a suitable anchor point or lifeline. In other words, the harness is not a permanent replacement for the guardrail, but a second line of defence covering the short interval when protection is absent.
Part (B) of Annex 5 of the regulation lists the minimum requirements for temporary edge protection systems. The provisions that will be most useful on site are:
| Subject | Annex 5 (B) requirement |
|---|---|
| Standard | The system is certified as conforming to TS EN 13374; it is not used in a class or type not covered by the certificate |
| Places of use | Slab edges; around lift, stair, chimney, shaft and light well openings; window and similar openings; edges of floor stairs; roof edges; around formwork areas |
| Components | Top guardrail, intermediate guardrail (or intermediate protection such as netting) and toe board |
| Height | The top of the top guardrail is at least 1 m above the working surface; toe board at least 15 cm and flush with the platform |
| Gaps (Class A) | The gap between the top guardrail, intermediate guardrail and toe board is at most 47 cm; if vertical members are used, the gap between them is at most 25 cm |
| Gap between the system and the structure | No gap is left; where unavoidable, at most 12 cm, provided the toe board is continuous |
| Documents | A copy of the certificate of conformity and the user and maintenance manual are kept on site |
| Installation | Done according to the manufacturer's instructions by employees trained in safe working methods |
The system class is chosen according to the slope of the working surface: under Annex 5, Class A is used on surfaces with a slope of less than 10°, i.e. flat slabs; on pitched roofs, Class B or C is required depending on the slope and fall height. Verify which class you are using from the supplier's certificate of conformity.
Lift shaft safety and covering shaft openings
You can close openings in the slab in two ways: covering the top of the opening with a load-bearing cover, or surrounding it with guardrails. The choice depends on the size of the opening and whether work will be done in it.
- Small service shafts and slab holes: Closed with a cover that can be walked on. In practice, a good cover is strong enough to carry a person and a wheelbarrow passing over it, overlaps every edge of the opening, is fixed from underneath with a frame or dowels so it cannot slide, and is marked "OPENING BELOW, DO NOT REMOVE". A loose plate or a thin board is not a cover but a trap.
- Large shafts and stairwells: Surrounded by temporary edge protection. Until the stair flight is complete, the stair edge is protected in the same way.
- Lift shaft: The lift shaft connects to the slab on every floor through the landing door opening. For lift shaft safety, a full-height guardrail or barrier is placed across the door opening on every floor; this barrier is not removed until the door frame is fitted. If installation work is to be done inside the shaft, a protective platform or net against material falling from upper floors is planned in the shaft, and this work is scheduled together with the subcontractor installing the lift.
- Window and facade openings: If the parapet height is insufficient or the frames have not yet been fitted, the opening is closed with edge protection.
A common mistake in covering shaft openings is for the services team to cut the cover to pass pipes through and leave the remaining narrow strips open because "they're small anyway". If a cover has been cut, the remaining gap must be closed again or the shaft must be surrounded with guardrails.
Slab-edge guardrails: installation sequence and common mistakes
Slab-edge guardrails are needed from the formwork and concrete stage onwards. The safest arrangement is to have the guardrail ready at the formwork edge before the slab concrete is poured and to install it as the first job on every new floor. For risks at the formwork stage, see our article on formwork and concrete pouring risks.
The most common mistakes on site:
- Missing intermediate guardrail or toe board. A single top rail will not stop a person sliding underneath or material pushed to the edge.
- Posts fixed to the edge haphazardly. Posts must be fixed with clamps, screws or a similar secure method and must not come loose on their own.
- Leaning material against the guardrail. The regulation prohibits leaving building materials in a way that loads the system. Bricks and rebar stacked at the edge both strain the guardrail and can fall over the toe board.
- Working on a ladder or trestle next to the guardrail. When a person's level rises, the guardrail drops to their waist. The regulation then requires additional measures; in most cases this means a harness and anchorage. For points to watch when using portable ladders, see our article on portable ladder safety.
- Using damaged and rotten timber. Cracked, cut or rotten material is not used in timber guardrails.
How is the removal of protection during work managed?
A significant share of falls through openings happen when protection has been removed for a job and not put back: the edge guardrail is opened when material is lifted onto a floor by crane, a section is removed for facade work, a shaft cover is lifted for services. Removal should therefore not be left to individual initiative; it should be tied to a simple permit system. For the general logic of permits, see our article on what a permit to work system is.
- Who gives permission? Open protection only with the approval of the site manager or a person they have authorised. The approval should state the location, reason and duration.
- Limit the opening. Only as much as the job requires is removed; the rest stays in place.
- Temporary personal protection. Everyone working at an open edge is attached with a full body harness to a suitable anchor point or lifeline. For choosing anchorage, see our article on anchor points and lifelines.
- Mark the area. The open section is surrounded with tape and a warning sign; people not involved in the work are kept out of the area.
- Supervision. While protection is open, a responsible person who knows the job is present in the area. The opening is not left unattended during breaks or shift changes.
- Reinstatement and check. When the job is finished, the protection is restored and the person who gave the approval checks it and closes the record. The regulation makes inspection mandatory when the system is altered.
Weekly inspection and records
Annex 5 (B) requires temporary edge protection systems to be inspected in the following situations and any non-conformities found to be corrected immediately: after installation, at least once a week, when the system is altered, and after conditions that could affect stability, such as an earthquake or strong wind. Doing this inspection with a form both standardises practice and creates the record to show at an inspection.
| Inspection item | Acceptance criterion |
|---|---|
| Slab edges | Continuous on every floor; top guardrail, intermediate guardrail and toe board complete |
| Lift shaft floor openings | Barrier in place and fixed on every floor |
| Shafts and slab holes | Cover fixed, overlapping and marked; no cut covers |
| Stairwell and flights | Guardrail or temporary protection in place |
| Posts and connections | No loose, bent or dislodged posts |
| Material storage | No material leaning against the guardrail or at toe board level |
| Opened sections | If a section is open, the permit record and responsible person are known |
| Timber elements | No cracked, cut or rotten elements |
Write the name of the inspector and the date on the form; the record should also show who corrected any gaps found and when. Under our OHS specialist service, we use this form with you during site rounds and report findings in writing. For other risks specific to the construction sector, see our sector page, and to see specialist and physician time for your number of employees and hazard class, the OHS obligation calculator. The rule is the same on residential and industrial building sites in Bursa and the surrounding provinces: install edge protection not after a floor is finished, but as the floor begins.
Frequently Asked Questions
Should a guardrail or a cover be used for a floor opening?
Small openings that may be walked over are closed with a fixed, load-bearing and marked cover. Large shafts, stairwells and lift shafts are protected by surrounding them with temporary edge protection. If work will be done in the opening, a guardrail is preferred.
What should the height of a slab-edge guardrail be?
Under Annex 5 of the Regulation on OHS in Construction Work, the top of the top guardrail must be at least 1 metre above the working surface and the toe board at least 15 centimetres. In Class A systems, the gap between elements cannot exceed 47 centimetres.
Is it prohibited to remove protection temporarily?
It is not prohibited, but it must be controlled. Where collective protection has to be removed temporarily, the regulation provides for personal protection with a full body harness and suitable anchorage. Removal should be subject to approval, the area should be marked, and when the job is finished the protection should be put back and checked.
How often is temporary edge protection inspected?
It is inspected after installation, at least once a week, when the system is altered, and after adverse conditions such as an earthquake or strong wind. Non-conformities found are corrected immediately.
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.