Mobile scaffold tower: how to build and use it safely

When do you choose a mobile tower?

A ladder is for short work with little risk. If you stand longer, higher or with heavier tools, you need a working floor with a guardrail under your feet. Article 7.23 of the Dutch Working Conditions Decree (Arbobesluit) says that for temporary work at height you choose the most suitable equipment, and that measures protecting everyone come before measures protecting one person. A mobile tower does exactly that: you stand on a floor, behind a rail.

Where the line between ladder and scaffold lies is explained in our article on ladder, mobile tower or work platform. Not sure what fits your job? The selection guide takes two minutes.

How high may a mobile tower be?

Volandis, the knowledge centre of the Dutch construction sector, has laid down the agreements between employers and employees in a guidance sheet called the A-blad Rolsteigers. It gives the limit from the European standard EN 1004-1:

• Outdoors: a maximum platform height of 8 metres.
• Indoors: a maximum platform height of 12 metres.

Those are the outer limits. The manufacturer's manual may set a lower one, for a narrow tower for example, and in wind the height has to come down. Going higher always requires separate strength and stability calculations.

Two things are never allowed: raising the working height with a ladder, steps, a crate or a pallet on the platform, and leaving out a component because it is in the way.

Building it: six rules from the guidance sheet

1. Follow the manufacturer's manual. It has to be present on site. The sticker on the frame is a reminder, not a replacement.
2. Build with two people. Only a tower specially developed to be built by one person may be built alone.
3. Place it on flat, level ground that can bear the load and set it plumb.
4. Use four stabilisers, unless the manual says otherwise. If they do not fit, for lack of space for example, additional measures such as anchoring are needed.
5. Guardrail first, platform second. You only step onto a platform once the guardrail and mid rail are in place all round. There are rails made to be fitted from the floor below.
6. Use components of one brand, unless a calculation shows the combination is sound, and remove damaged parts at once.

The distance between two floors is 2.25 metres at most. Only the first floor may be higher: up to 3.4 metres above the ground.

The working floor: guardrail and toe board all round

The floor you work on needs a guardrail, a mid rail and a toe board of at least 15 centimetres all round. The toe board keeps tools and material on the floor, so nothing falls down.

There is one exception. If the rail is in the way of the work, it may be left off on one 2-metre section, but only if the tower stands less than 15 centimetres from the facade. The diagonal braces always stay in place.

• Climb on the inside only, never on the outside.
• Carry nothing in your hands while climbing. Small tools hang on a belt, larger items go up on a rope.
• Do not use the floor for storage. The platform states the maximum load: 150 or 200 kilos per square metre, depending on the class.
• Do not attach a harness to the tower. It is not built to take the forces of a fall. Your protection is the guardrail, during assembly too.

Moving it

The decree puts it briefly: a mobile scaffold is secured against unintended movement. The guidance sheet turns that into: all castors braked as soon as anyone climbs or uses the tower.

For moving the tower, the guidance sheet gives this:

• Nobody is on it. The sheet names moving a tower with someone on it as one of the causes of accidents.
• By hand only, over flat and stable ground.
• The stabilisers stay on and are lifted just a few centimetres off the ground.
• If the manual says nothing about moving, do not move a tower higher than 4.2 metres.

Checks and inspection

• Before first use and after every change. Article 7.34 of the decree requires a competent person to check the structure before it is taken into use, after every change, after a period in which the scaffold was not used and after abnormal weather.
• Every working day. Before you go up, check that the tower is complete, undamaged and in the right condition. The guidance sheet has a checklist at the back for this.
• Every year. The components are inspected at least once a year by a trained expert for wear, deformation and cracks, and more often with intensive use.

How this works for ladders is covered in our article on ladder inspection.

Who may build a mobile tower?

Article 7.23b of the decree says a scaffold is only erected, dismantled or substantially altered under the direction of a competent person, by workers who have had adequate and specific training for it. That training covers, among other things, the assembly plan, safe erecting and dismantling, preventing falls, changing weather and the permitted load.

The guidance sheet says the same in plain words: only well-instructed people build the tower, and they follow the manual.

Wind

The guidance sheet on mobile towers gives no wind force itself: the working height has to come down in wind, and the limit is in the manufacturer's manual. The Volandis sheet on pitched roofs is specific. When wind force 6 or more is expected, work on aluminium mobile towers stops, and ladders are not used either. Netting or sheeting on the tower catches extra wind and is only allowed under the manufacturer's conditions.

How to judge how hard the wind is blowing is explained in our article on ladders and wind.

Does this apply to the self-employed?

Yes. Article 9.5 of the decree lists the rules a self-employed person must follow. Articles 7.23 to 7.23d are in it, and so are the second and third paragraphs of article 7.34: no overloading, and securing against unintended movement. If you work as a self-employed person on a construction site, the remaining articles of chapter 7 apply too.

Belgium

The Belgian rules are in Book IV, Title 5 of the Code on Well-being at Work. Three points stand out:

• The employer using the scaffold appoints a competent person who has been trained for it.
• Only workers with the required training may work on a scaffold or help erect, dismantle or alter it.
• When a mobile tower is moved, no worker may be on it, unless the tower is specially designed for that.

More on the Belgian rules in our article on the Code.

Frequently asked questions

May you build a mobile tower on your own?

Normally not: the guidance sheet asks for at least two people. The exception is a tower specially developed to be built by one person.

How high may a mobile tower be outdoors?

Free-standing up to a platform height of 8 metres, and indoors up to 12 metres, if the manufacturer's manual allows it. Higher is only possible with separate calculations.

May you attach a harness to a mobile tower?

No. According to the guidance sheet the tower is not suited to take the forces of a fall. That is why you always stand behind a guardrail, during assembly too.

May you put a small stepladder on the platform to reach a little higher?

No. The working height may not be raised with a ladder, steps, a crate or a pallet. If you cannot reach, you need a taller build.

How often does a mobile tower need inspecting?

The components at least once a year by a trained expert. On top of that you check the tower after building it, after every change and at the start of every working day.

Sources

• Dutch Working Conditions Decree (Arbobesluit), articles 7.23, 7.23b, 7.34 and 9.5
• A-blad Rolsteigers (Volandis, December 2021, in Dutch)
• A-blad Hellende daken (Volandis, fourth edition 2018, in Dutch), section 3.1.3 on wind
• Code on Well-being at Work, Book IV, Title 5 (Belgian Federal Public Service Employment), articles IV.5-7, IV.5-11, IV.5-14 and IV.5-15

This article is a practical explanation, not legal advice. Sources checked on 8 October 2026.