Fall protection on a roof: the options for flat and pitched roofs

On a roof where you can fall 2.5 metres or more, you must first secure it collectively: a fence or guardrail at least 1 metre above the working surface, or a scaffold or working platform. If this is not possible, or only partially possible, use a safety net or a harness with a line attached to an anchor point. On a flat roof, choose work area restraint (so you cannot reach the edge) or a fall arrester with a fall line or fall block that has been tested for a fall over an edge. On a pitched roof, Petzl describes working on a rope with a self-retracting fall arrester, optionally with a positioning line.

What does the law say about fall protection on a roof?

The rules are set out in Article 3.16 of the Working Conditions Decree. This applies to all work involving a risk of falling, including work on roofs:

• Paragraph 2: there is always a risk of falling in hazardous conditions, near openings in floors, or if you can fall 2.5 metres or more.
• Paragraph 1: where possible, install a safe scaffold, scaffold tower, platform or working platform, or prevent the danger with suitable fencing or guardrails.
• Paragraph 3: a fence or guardrail is suitable if it protects up to at least 1 metre above the working surface, or meets the requirements for floor edge protection in the Building and Living Environment Decree.
• Paragraph 5: if this is not possible, or only partially possible, or if installing it is more dangerous than the work itself, use safety nets, safety harnesses with fall arrest lines or other technical equipment providing at least the same level of protection. Collective measures take precedence over individual ones.

A harness is therefore not the first choice. In its advice on roofing work, Petzl makes the same distinction: for short, temporary work, a personal fall arrest system may be sufficient; for longer work, collective protection simplifies the work because no one needs a personal fall arrest system.

What options do you have on a roof?

Option	What it does	When	What you need
Fence or guardrail	Collective: no one can fall over the edge	First choice, especially for longer work	Edge protection at least 1 m above the working surface
Safety net	Collective: catches a fall	If edge protection is not possible or only partially possible	A sufficiently strong and large net in the right place
Work area restraint	Keeps you away from the fall hazard zone; does not catch a fall	Flat roof, work is not done at the edge itself	Harness, line, anchor point
Work positioning	Keeps you secured at your work area; does not catch a fall	Pitched roof, ridge	Positioning line plus a separate fall arrest system or collective protection
Fall arrester	Stops a fall and limits the force to a maximum of 6 kN	Work at the edge, short work, or as a supplement	Fall arrest harness, fall line with energy absorber or fall block, anchor point, clear space

You can read about the difference between a positioning line and a fall line in Positioning line or fall line: what is the difference?.

Flat roof: work area restraint or fall arrest?

With work area restraint, the line is adjusted so that you cannot reach the edge. According to Petzl, such a system is not designed to catch a fall. If you need to work at the edge itself, you need fall arrest. On a flat roof, the line will pass over the roof edge in the event of a fall.

Petzl tests the ABSORBICA-I and ABSORBICA-Y (webbing and rope versions) for a fall over an edge: 140 kg, 2 m fall height, over a steel edge with a radius of 0.5 mm. A sling fall with a 1.5 m horizontal distance is also part of the test. The manual provides the following rules for work on a platform with an edge:

• The anchor is at least 6.1 m above the ground.
• You do not move more than 1.5 m sideways from the anchor. If you need to, use a line according to EN 795 type C (rope) or D (rail).
• Choose an anchor above the edge so that the line does not bend over the edge at an angle of less than 90° in the event of a fall.
• If the edge is sharper than 0.5 mm or has a burr, prevent falling over the edge or install edge protection.

Can a fall block be used over a roof edge?

Only if the manual allows horizontal use. For Tractel Blocfor fall blocks, this varies by model. The user manual for the Blocfor ESD/EVO series (2026) states the following:

Fall block	Line	Horizontal over an edge	Anchor to edge (L min)	Max. sideways (M max)
Blocfor 6 ESD	6 m polyester webbing	Yes	1 m	1.5 m
Blocfor 10 ESD galva	10 m galvanised steel cable	Yes	1 m	1.5 m
Blocfor 10 ESD SR	10 m polyethylene rope	No	n/a	n/a
Blocfor 10 ESD inox	10 m stainless steel cable	No	n/a	n/a
Blocfor 20 EVO ESD galva	20 m galvanised steel cable	Yes	1 m	1.5 m

Tractel also sets the following conditions: the anchor is at the same height as the edge or higher, the edge has a radius of at least 0.5 mm without a burr, the webbing makes an angle of at least 90° over the edge in the event of a fall, there are no obstacles in the sling path and there is a rescue plan. For horizontal use, the clear space underfoot is 5 m: maximum 4 m fall distance plus 1 m margin, plus the deflection if you are hanging from a flexible line (type C). Tractel also mentions fragile roofs, such as fibre cement: if in doubt, lay down a sturdy walking surface. You can read how to calculate clear space in Clear fall space: how much height does a fall line really need?.

What do you use on a pitched roof?

On a pitched roof, you can slide before you fall. This determines which fall arrester works:

• Fall block: according to Tractel, do not use the Blocfor if the block may not engage, and it also mentions inclined surfaces.
• Self-retracting fall arrester on rope: the Petzl ASAP LOCK (EN 353-2, 50 to 140 kg) may be used at any rope angle between 0° and 90° and locks at 2 m/s. Petzl warns that you may slide more slowly on a gentle slope than that speed. Therefore, place a stopper knot in the rope if you would otherwise hit an obstacle.
• Access: Petzl describes ascending a roof via a rope with a detachable anchor, where you secure the climb with the ASAP.
• Positioning: with a GRILLON (EN 358, working load 140 kg), you hang taut in your line and stay under the anchor. The GRILLON is not a fall arrester; combine it with a fall arrest system or with collective protection.

What anchor point do you attach to?

Both Petzl and Tractel require an anchor point according to EN 795 with a strength of at least 12 kN. On a roof without fixed anchors, you can use a temporary anchor around a sturdy structure:

• CONNEXION FIXE or VARIO (EN 795 type B, one person): maximum 22 kN transmitted to the structure when tightened around it, 45 kN when laid around the structure. Keep the angle between the two webbing ends below 90°. Pay attention to the stretch under load: 20 mm for the FIXE, 800 mm for the VARIO 30-200 cm and 200 mm for the VARIO 200-400 cm. That stretch counts in your clear space.
• GRILLON as a temporary anchor (EN 795 type B, maximum 18 kN), or as a horizontal lifeline (EN 795 type C) for one person with approximately 1 kN pre-tension. No fall block may be used on such a lifeline; a fall line with an energy absorber may.

Checklist before going onto the roof

1. Can you fall 2.5 m or more, or are there skylights or other openings? Then there is a fall hazard.
2. Can a fence, guardrail or scaffold be installed? That takes precedence.
3. Choose the personal system: restraint, positioning or fall arrest.
4. Check the anchor point: EN 795, at least 12 kN, preferably above you and at or above the edge height at an edge.
5. Look at the edge: radius of at least 0.5 mm and no burr? If not, edge protection.
6. Check whether your fall line or fall block may be used horizontally over an edge and stick to the maximum sideways distance.
7. Calculate the clear space under the edge, including the stretch of the anchor or the deflection of the lifeline.
8. Check whether the roof can support you and establish a rescue plan.

Frequently asked questions

From what height is fall protection on a roof mandatory?

According to Article 3.16 of the Working Conditions Decree, there is always a risk of falling if you can fall 2.5 metres or more. In hazardous conditions or near openings in the roof, this also applies below that height.

Can I use a harness instead of a guardrail?

Only if collective protection is not possible or only partially possible, or if installing it poses more danger than the work itself. Collective measures take precedence.

Is every fall line suitable for a fall over the roof edge?

No. Check the manual whether the line has been tested for a fall over an edge. This is the case for the ABSORBICA-I and -Y and for some of the Blocfor fall blocks, for an edge with a radius of at least 0.5 mm.

How much space do I need under the roof edge?

For a Blocfor fall block used horizontally over an edge, 5 m under your feet, plus any deflection. For the ABSORBICA on a platform, at least 6.1 m between the anchor and the ground.

Read about products and more

• Petzl CONNEXION VARIO adjustable anchor webbing
• Tractel Blocfor ESD fall block 6, 10 and 20 m
• Petzl GRILLON adjustable positioning line
• Petzl ASAP LOCK KIT self-retracting fall protection
• All fall blocks and all anchorages
• Knowledge base: Fall protection inspection: how often and what to look for?

Sources: Working Conditions Decree Article 3.16 (wetten.overheid.nl, applicable from 1 August 2026); Petzl user manuals GRILLON, ABSORBICA-I/Y (L0047000C), ASAP LOCK and CONNEXION; Petzl Tech Tips "Roof operation", "General principles for work at height" and "Tests of ABSORBICA lanyards in a fall over an edge"; Tractel user manual Blocfor ESD/EVO (2026) and product sheet Blocfor 6 ESD. Photos: Petzl (header), Tractel product photo. Diagram: Hef en Hijs Online. Last checked on 13 November 2026. This article does not replace the user manual of your fall protection or a risk assessment.