10 Most Common Mistakes When Using a Mobile Scaffold Tower

==========

Mobile aluminium scaffolding is designed to be safe — but only when used correctly. The majority of working-at-height accidents on scaffolding are not caused by structural failure; they are caused by user error: incorrect assembly, overloading, or ignoring rules that are explicitly stated in the product manual.

This article covers ten mistakes that recur most frequently on job sites. For each one we explain what the risk actually is and how to prevent it.

Mistake 1: Overloading the Platform

What happens: Users add materials (paint, tools, bags of mix) to the platform without accounting for the fact that the maximum load capacity covers the combined weight of people and all materials together.

What's at risk: Exceeding the load class causes permanent deformation of the platform decking or load-bearing profiles. The structure may not fail immediately — damaged components can survive several more uses before failing without warning.

How to avoid it: Check the label on the tower. Load class 2 means 150 kg/m²; load class 3 means 200 kg/m². This limit applies to the entire platform area — person plus tools plus materials combined. If you're working alone with light tools you'll easily stay within limits. If two people are on the tower along with a bucket of plaster and a tin of paint, add it up.

Mistake 2: Moving the Tower With a Person or Materials on the Platform

What happens: Moving the tower a metre sideways seems quicker than climbing down, repositioning, and climbing back up. In practice, a large proportion of users take this shortcut.

What's at risk: A mobile scaffold tower is not designed to be moved under dynamic load. Movement shifts the centre of gravity, the castors can catch on a floor irregularity, and the tower can tip rapidly. A fall from 3–4 metres is life-threatening.

How to avoid it: Always descend from the tower before moving it. Remove any loose materials from the platform. Only then reposition the tower. It takes longer — but it is a fundamental safety rule explicitly stated in EN 1004 and in the COSMOS and ALUBERG manuals.

Mistake 3: Omitting or Incorrectly Fitting the Outriggers

What happens: Outriggers are treated as a cumbersome accessory that takes up space and slows down assembly. On a flat indoor floor they appear unnecessary.

What's at risk: Outriggers substantially reduce the risk of the tower tipping sideways. EN 1004 specifies maximum working platform heights at which the tower is stable without outriggers — for most models this is 4–6 m. Above this threshold outriggers must be fitted. Without them, the tower is outside its certified parameters.

How to avoid it: Read the manual — the maximum height without outriggers is stated explicitly for your model. Always respect this limit, even when the outriggers seem superfluous.

Mistake 4: Working Outdoors Above the Permitted Height

What happens: EN 1004 distinguishes between maximum heights for indoor and outdoor use. Without anchoring, the outdoor limit is 8 m and the indoor limit is 12 m. Many users are unaware of this distinction or choose to disregard it.

What's at risk: Outdoors, the tower is subject to lateral wind loading. Even a moderate breeze (Beaufort 3–4, 12–28 km/h) can cause a tall tower to sway. EN 1004 explicitly prohibits use of a mobile tower outdoors in strong wind or storm conditions.

How to avoid it: When working outdoors, observe the 8 m limit without anchoring. If you have any doubt about wind conditions, stop work — the tower cannot be used safely in conditions the standard does not cover.

Mistake 5: Unsuitable Ground Surface Under the Castors

What happens: The tower is set up on unpaved ground, paving with gaps, wet concrete, or a floor with a threshold or other obstruction.

What's at risk: An uneven or slippery surface causes the castors to slip uncontrollably or to snag. During movement or work on the tower this can result in a sudden tilt or tip-over.

How to avoid it: Always set up the tower on a level, firm, and dry surface. If the site does not permit this, use adjustable levelling feet (available as accessories for both ALUBERG and COSMOS) and prepare the surface first. Outdoors on uneven ground, use ground pads under the castors.

Mistake 6: Not Locking the Castors Before Stepping onto the Tower

What happens: The user steps onto the tower before locking the brakes on all four castors.

What's at risk: The tower moves under the weight of the person stepping on or working from it. Even a small shift at a height of 2–3 m can cause loss of balance and a fall.

How to avoid it: The rule is simple: lock all castors first, then step on. Unlock only after fully descending. On COSMOS Marte models equipped with the ServoTech braking system, the lock engages automatically when weight is placed on the bottom rung — but this does not mean the step can be skipped. Always verify the lock visually.

Mistake 7: Assembling Without Reading the Instructions

What happens: The tower was assembled "by eye" or by copying how a colleague did it last time. The manual was left in the box or has been lost.

What's at risk: Incorrect assembly sequence or omitted components (toe boards, cross braces, transoms) result in an assembly that does not meet certification parameters. Such an assembly can be unstable even under light loads.

How to avoid it: The manual must always be available at the work site or at least readily accessible. Every ALUBERG and COSMOS scaffold we supply comes with documentation in the local language. If you've lost it, contact us — we'll send a replacement copy.

Mistake 8: Using the Tower as a Support Point for Other Structures

What happens: Another tower or ladder is leaned against the scaffold, or a block and tackle or other load is suspended from it.

What's at risk: The tower is certified for vertical loading on the platform and its own structural weight. Lateral or eccentric loading (leaned ladders, suspended loads) can cause instability and tipping.

How to avoid it: Use the tower exclusively for its intended purpose — as an elevated work platform. If you need a heavier-duty or differently configured support structure, contact us — bespoke industrial solutions exist for this (e.g. the COSMOS Super Tukan modular platform).

Mistake 9: Working From the Top Rung of the Internal Ladder or From a Separate Ladder Alongside

What happens: The scaffold's working height is insufficient, so the user stands on the highest rung of the internal access ladder, or props a separate ladder against the tower to gain extra reach.

What's at risk: Working from an internal ladder rung is outside the scope of certification — the tower is designed for work from the platform, not from a rung. A separate ladder leaned against the tower creates an unstable assembly with two uncontrolled support points.

How to avoid it: If the working height is insufficient, choose a taller configuration (a higher frame or an additional section). Alternatively, move to a platform with a greater working height or a tower platform. Never work from a rung of the internal access ladder.

Mistake 10: Ignoring Regular Inspection and Component Wear

What happens: The tower is used for a year or more with no inspection. Cracks in profiles, worn quick-release joints, or damaged castor brakes go unnoticed.

What's at risk: A damaged structure can fail without visible warning — especially under impact or under loading that would otherwise be within safe limits.

How to avoid it: Set a regular inspection schedule (minimum once a year, ideally twice). Users should carry out a visual check before every assembly. For a detailed guide on what to inspect and how to document it, see our article on aluminium scaffold inspection.

Summary

The ten mistakes described above have one thing in common: all of them are preventable by reading the manual and following a few basic rules. Certified ALUBERG or COSMOS Marte scaffolding is an exceptionally safe tool when used correctly — but certification does not guarantee safety under conditions for which the product was not designed.

Have questions about correct use, or looking for the scaffold that best fits your operation? Get in touch.