Floor Openings on Site: How to Cover and Protect Them (UK)

You're stripping out a first floor, or the stair hasn't arrived yet, and there's a hole in the deck. Someone puts a sheet of ply over it and the job moves on. Is that enough? This guide covers what the law actually asks for with floor openings on construction sites, the practical choice between a cover and edge protection, and how to get it written into your RAMS so the protection is still there next week.

Key takeaway: an opening is a planned stage of the job, not a surprise. Decide how each one will be protected before it is made, write that into your method statement, and check it every time another trade has been through.

What counts as a floor opening?

In practice, any gap in a floor or deck that a person, or their foot, could go through. On a typical job that includes:

• Stairwell openings before the staircase goes in, or after an old one is taken out
• Areas where joists or floorboards have been lifted during strip-out or refurbishment
• Service risers, lift shafts and openings left for ducts, chutes or plant
• Gaps at the leading edge of new decking
• Roof lights and fragile roof sheets, which have their own rules (see regulation 9 below)

It doesn't matter how far the drop is. The Work at Height Regulations 2005 have no minimum height. The duty is about preventing a fall "liable to cause personal injury", and a fall through a single storey can easily do that.

What does the law say about floor openings?

There is no single regulation called "floor openings". The duties come from the Work at Height Regulations 2005, read together with the general risk assessment duty under regulation 3 of the Management of Health and Safety at Work Regulations 1999. The parts that matter most for openings are:

• Regulation 4: planning. Every employer must ensure work at height is "properly planned", "appropriately supervised" and carried out as safely as is reasonably practicable. (Regulation 4)
• Regulation 6: the order of controls. Avoid work at height where you reasonably can. Where you can't, take measures to prevent a fall, and only then fall back on measures that minimise the distance and consequences of a fall. (Regulation 6)
• Schedule 2: guard rails and barriers. The top guard rail must be at least 950mm above the edge, and any gap between rails must not exceed 470mm. Toe boards must be suitable to stop people, materials and objects falling. (Schedule 2)
• Regulation 9: fragile surfaces. Where people have to work on or near something that will not take their weight, you need platforms, coverings or guard rails, plus prominent warning notices at the approaches. (Regulation 9)

HSE's practical guide for small contractors, Health and safety in construction (HSG150), turns this into site rules. It says guard rails should be positioned "at all fixed edges and openings as early as practicable" in the construction sequence (paragraph 259), and that covering the opening is an acceptable alternative to a barrier, provided the cover meets certain standards (paragraphs 152 and 153).

Cover or edge protection: which should you use?

Both are collective protection, which is why they come before harnesses or nets. The right one depends on whether people need to work at or across the opening, and how long it will be there.

Comparison: ways to protect a floor opening

• Fixed cover. Best for: small to medium openings no one needs to use yet (risers, small stairwells, lifted sections). Key requirements: strong enough for any likely load including a person, fixed so it cannot be knocked off, marked with a warning. Main weakness: gets lifted by the next trade and not put back.
• Guard rails and toe boards. Best for: stairwells, lift shafts and larger openings that must stay open for access or lifting. Key requirements: top rail at least 950mm, no gap over 470mm, toe board, fixed to something that can take the load. Main weakness: takes up floor space and gets removed for deliveries.
• Other barriers (proprietary panels, mesh systems). Best for: longer-term openings and leading edges. Key requirements: at least 950mm high and secure, with protection equivalent to guard rails (HSG150 paragraph 150). Main weakness: cost, and only as good as the fixing.
• Tape or bunting on its own. Best for: keeping people away from a cover that is already in place. Key requirements: HSG150 suggests tape to direct people around covers, not as the protection itself. Main weakness: tape marks a hazard, it does not protect it.

What makes a floor opening cover acceptable?

HSG150 paragraph 152 sets out what a cover needs. Turned into a checklist you can use on site:

1. Strong enough. It must support any load likely to be put on it, including the weight of a person. Think about materials being set down on it too, not just someone stepping on it.
2. Fixed in position. Screwed, bolted or otherwise secured so it cannot slide or be kicked aside. A loose board resting on the edges does not meet this.
3. Marked. HSE gives the example wording "Hole below, do not remove". Mark it so the warning is still readable after a week of dust.
4. Bigger than the hole. Enough bearing on every side that it can't drop in.
5. Kept out of the walking route where possible. HSG150 paragraph 153 suggests directing people around covers, for example with high-visibility tape.

A cover that meets all five, then gets lifted by the electrician running cables and left propped against a wall, protects nobody. The control that matters most is the one that controls who can lift it.

What does this mean for a small contractor day to day?

Most falls through openings are not about missing equipment. The boards and rails are usually on site. The gap is in planning and handover. A few habits close most of it:

• Sequence the strip-out. Don't lift more floor than you can protect that day. Work in sections, and make the protection step part of each section, not a job for the end.
• Protect before you open. Where you can, fit edge protection or have the cover cut and ready before the boards come up. HSG150's advice to fit protection "as early as practicable" applies to refurbishment as much as new build.
• Name who can lift a cover. One person signs it off and puts it back. Anyone else who needs access asks first.
• Check after every trade. A quick walk round at the start of each shift, and after any trade has worked near an opening, catches the cover that was moved and not replaced.
• Tell new starters on day one. Show agency staff and labourers where the openings are during their site induction, and repeat it in a toolbox talk when the layout changes.

Openings stay on HSE's radar. In September 2026 it prosecuted a housebuilder where a stairwell opening had no secured cover and no edge protection, and the inspector noted that simple measures would have prevented the fall.

How to write floor openings into your RAMS

Regulation 4 asks for planning, and the method statement is where the plan lives. A useful RAMS for working at height treats openings as their own step, not a line in the hazard list. It should say:

1. Where each opening is, or will be, and roughly when it will be formed.
2. Which protection goes on each one (cover, guard rail or barrier) and who fits it.
3. The sequence: how much floor is opened at once, and that protection goes on before work moves on.
4. Who may lift a cover, and how it is replaced and re-checked.
5. How often openings are inspected, and what happens when protection is found missing.
6. How the arrangements are briefed to everyone on site, including other trades and visitors.

If an opening has to be uncovered for a specific task, such as craning in a stair or lowering plant, treat that window as a controlled activity in its own right. Some sites run a permit to work for it. Others cover it in a short task-specific safe system of work. Either way, the paperwork is only useful if the person on the floor follows it. A document supports safe work, it does not create it.

This is where swiftRMS helps. Describe the job, for example "strip out and replace first-floor joists in a two-storey house", and it drafts a task-specific RAMS that includes the opening protection, the sequence and the checks, referenced to the Work at Height Regulations 2005. Trade starting points are there for carpenters, scaffolders and roofers. Every document is an AI-generated draft: a competent person must review it and make it fit the actual site before it is used.

Draft your first working at height RAMS free. No card needed, and it takes a couple of minutes. See pricing when you are ready for your team.

Frequently asked questions

Is a sheet of plywood over a floor opening enough?

Only if it meets the standard HSE describes: strong enough for any load likely to be placed on it, including a person, fixed so it can't be dislodged, and marked with a warning such as "Hole below, do not remove". An unfixed, unmarked board resting over the gap does not meet that standard and is easily moved by the next trade.

Do floor openings need guard rails or covers?

Either can be acceptable. HSE guidance treats a properly fixed and marked cover as an alternative to guard rails. Covers suit openings nobody needs to use yet. Guard rails, with a top rail at least 950mm high and no gap over 470mm, suit stairwells and shafts that must stay open for access or lifting.

Is there a minimum height for floor opening protection?

No. The Work at Height Regulations 2005 set no minimum height. The duty is to prevent, so far as reasonably practicable, a fall liable to cause personal injury. A fall through a first-floor opening, or even a foot going through a smaller gap, can cause serious injury, so it needs to be planned and protected.

Who is responsible for protecting floor openings?

Every employer whose workers are exposed must make sure work at height is properly planned, supervised and carried out safely, under regulation 4. In practice the contractor forming the opening should protect it, and the site's arrangements should make clear who checks it and who may remove a cover. Agree this before work starts.

Should floor openings be in the RAMS?

Yes, where the work creates or exposes them. Regulation 4 requires work at height to be properly planned, and the method statement is where that plan is recorded. Include where the openings are, which protection is used, the sequence of work, who can lift covers, and how often the protection is checked.