Tower scaffold definition
A mobile tower scaffold is a lightweight proprietary designed and manufactured system that allows for fast, easy and convenient access to tasks at height by assembling and adding purpose made components.
Mobile towers provide a safe working platform for low to medium heights. Higher heights can be achieved by the addition of purposely designed adjustable legs, often called ‘outriggers’. The addition of outriggers massively increases the footprint of a mobile tower an thus, massively increases its stability.
Mobile towers tend to come with adjustable feet to allow them to be levelled initially as this is vital for their stability. Wheels on the feet can be locked in position making them solid and immovable. Other components act as guard rails as well as bracing.
Mobile tower scaffolds can come in various materials. These mainly are aluminium, steel and fibreglass. Care must be taken when erecting mobile tower scaffolds as assembling them incorrectly can cause instability.
Their use is often preferred over step ladders in certain situations as they provide a much safer working platform over a greater area. Mobile towers also provide the advantage of having a guard rail for the user whichever direction they face without becoming unsafe.
They also provide additional space for tools and materials. The duration and nature of the task is also important. If the task is more involved and requires a longer duration using both hands continuously, a tower is the safer option. In slightly smaller situations, a podium tower could be a suitable option. In fact, you can further read our article on podium towers and podium steps here.
Usually lightweight, (steel versions are heavier) various types allow themselves to be dismantled into sections or folded into a compact footprint. This, combined with having wheels that can be locked and unlocked make for better storage or moving to a new location.
From a construction site perspective, I, as a site manager cannot allow anyone to erect a mobile tower scaffold unless they have what we call, “PASMA” training. This basically is a mobile tower erecting and dismantling course which usually takes one day and ensures that a tower is erected correctly for obvious reasons. This effectively renders a person ‘competent’ to erect one. You can further read our article PASMA training here.
In a domestic situation where one is not bound by Health & Safety legislation, this is unlikely to happen. It doesn’t intrinsically make it unsafe for you to erect a mobile tower however if you apply some basic common sense and follow the manufacturers guidelines to the letter. If you do that, you should be okay. In extreme situations, a MEWP or Mobile Elevating Working Platform might be needed. You can read more in our article What is a MEWP? here.
Tower scaffold parts
So, we have covered the overview of what a tower scaffold is, what it can be made from and what it can be used for.
Tower scaffolds are basically made up from five components.
Frames – These are the main structural fixed elements that form the rigid sides to a mobile tower.
Braces – These are the straight components that attach to the frames either horizontally or diagonally. These are easily identified as the diagonal braces are slightly longer than the horizontal braces and the ends are usually colour coded either red or blue.
Platforms – These are the components which the user will stand on during use and they drop into position between the frames. The platforms usually have a hinged trap door in them to allow you to climb up through. It is absolutely vital that you do not climb a tower scaffold from the outside as it could topple over! Always climb a tower scaffold internally and pass through the hinged trap doors. This keeps your weight inside the footprint.
Legs – These components, often called ‘outriggers’ attach to the corners of the tower to increase stability at greater heights. The use of outriggers, and the number of them needs to be assessed. The main things to consider are if they are needed would be the height you need to achieve and the location of the tower.
For instance, if you need to reach a greater height but your tower is against a brick wall, you may only need two outriggers. If your tower doesn’t have a fixed structures around it, you may need four. One on each corner. Conversely, if you don’t need to achieve a great height, you may not need any at all.
The manufacturers guides will usually let you know at what height they need to be introduced.
Wheels or Castors – The final components are the wheels or castors. These are vital components as they ensure that a mobile tower can be levelled and moved easily. They consist of rubber wheels with steel centres and a threaded leg that can be wound to adjust its height perfectly. The wheels also come with a brake stop mechanism that can be engaged by standing on it.
Note: Additional ‘toe boards’ can also be supplied. These are placed and clipped around the working platform so that any materials or tools do not get kicked off the edge of the working platform and injure someone below. They could also save you from damaging some expensive tools like drills.
PASMA is an acronym that stands for the Prefabricated Access Suppliers and Manufacturers Association. As I eluded to earlier, in a construction site environment, we are bound by Health & Safety legislation as well as guidelines and Approved Codes of Practice. This means that we need certain designated individuals to hold a PASMA certificate of training. This is so that we can prove that the designated individual has reached a level of competence that allows him (or her!) to erect a tower scaffold for another person to use.
These PASMA courses usually last one day and can now be found online. They are not strictly necessary in a domestic environment but some may feel that it’s a worthwhile training certificate to have.
Essentially, if you always read and follow the manufacturers instructions manual and never use the equipment beyond its limitations or what it was designed for, you should be okay.
If you wish to explore courses, you can go to the PASMA website by clicking here.
How to put up a tower scaffold
Mobile towers differ in their design as they come from differing manufacturers. It would be incredibly difficult to explain definitively how to erect a mobile tower. The best advice is to follow the individual manufacturers instruction manual that will come with your new tower.
The main thrust of erecting usually follows a few basic steps and is much easier if you have someone to help pass you certain components as you get higher.
The adjustable wheels are slotted inside the bottom frame sections. (if you already have level, firm ground, you can pre wind these to a set height so they don’t need adjusting later)
Horizontal and diagonal braces are then attached to the side frames which now make it stand upright. It is important to say at this stage that you MUST check the manufacturers guidelines on attaching the braces.
The diagonal braces are quite straight forward and their ends hook over the horizontal parts of the side frames but the horizontal brace attachments need to be correct or this could cause instability. The hook ends attach to the vertical parts of a side frame. This stops sideways movement. The diagonal braces should also run in opposite directions on the front and back faces of the tower.
To be clear, on most aluminium tower scaffolds, the horizontal braces must be clipped to the vertical parts of the frame section, not the horizontal parts of the frame section. This gives it rigidity. Next, the platform sections are dropped into the frames from inside at the level you need. If going higher with more frame sections, this is usually head height.
This is where your helper is invaluable! You then climb up the inside of the mobile tower, through the hatch and firstly attach the next set of frames along with the horizontal braces as they will also act as a handrail. You then just repeat the process. If a greater height is needed, fitting the adjustable outriggers is advisable at this stage.
Steel tower scaffold
Steel tower scaffolds are similar in nature but from my experience of them, assemble differently. Rather than clipping components together, they tend to ‘slot’ together and only come with diagonal braces. This is due to steel type towers being four sided with their frame sections being used on all sides rather than two sides like an aluminium tower.
The frame sections slot into each other and the diagonal braces run internally from corner to corner to minimise twisting and add rigidity.
These types of towers are often heavier and again, in my experience have not ‘felt’ safe to use when I’ve used them. When using them, you need to expect a lot more movement than on an aluminium type tower. I therefore won’t be recommending any today as don’t want anyone to feel unsafe. You still find these types of towers in peoples back gardens or yards. They are usually rusty and used by people who take their safety into their own hands!
Mobile tower scaffold dimensions
Mobile tower scaffolds, as you can imagine come in many size configurations. Rather than go through every variation, We’ll out line basic size variations.
Mobile tower scaffolds can come in what is called ‘single’ widths and ‘double’ widths. Single width towers have enough space in the frame for one platform that are generally 600mm wide. Double width tower frames have enough space to fit two platforms side by side giving you a 1200mm width. The length of a tower can be approximately 1500mm to 1800mm.
Typical loadings for towers range from 275Kg to 860Kg for heavy duty variations. Generally, heights can be from approximately 1-2m to 10m with outriggers.
Mobile tower safety considerations
Due to a mobile tower scaffolds lightweight nature, the higher it gets built, the more you need to be sure about its stability. Manufacturers as you expect carry out extensive testing of their products. This is so that they can provide you with specific guidance, especially with the height to base stability ratio including the point at which outriggers will be needed. As a guide, a 3m platform height is usually when you would look to introduce outriggers.
Ground Conditions – Always ensure you have firm ground under your tower wheels. Uneven ground is fine as you can adjust the wheels but it must be firm. Never use anything else to level the wheels like bricks or blocks.
Sheeting or materials – Be aware of any sheeting or plyboard for example on a tower scaffold. In higher winds, this can cause a tower to blow over with the additional surcharge.
Over reaching – Never over reach outside of the tower perimeter. Excessive over reaching can alter the centre of gravity and cause overturning.
Work activity – Tasks that may cause an excessive lateral force like jet washing for example could cause instability.
Hoisting materials – Hoisting heavy materials outside of a tower could cause it to overturn. If possible, try to pass materials up through the centre of a tower through the trap hatches.
Climbing – Always climb the tower from the inside and pass through the trap hatches. Climbing outside will could cause it to overturn or you could lose your grip higher up and have nothing to break your fall.
Components – Only use the components that belong to the tower, not any components from another manufacturer.
Hatches – Hatches must be closed as soon as possible to avoid someone falling through them.
Extra height – Never use additional equipment like step ladders on platforms. Any movement could cause a serious fall and using these will place you above a guard rail.
Brakes – Always ensure you have the brakes fully engaged before use.
Moving a tower – Never move a tower with someone on it. It’s just too dangerous and could cause serious injury if overturned.
Summary and tower suggestion
So, in summary, we have covered what a mobile tower scaffold is, what they can be made of, why they are used, the training that is available if you require it and some safety considerations to think of to demonstrate good practice. Read our article on how to clean gutters here!
We have a great tower access suggestion for you below.
BPS Access Solutions Aluminium Scaffold Tower
What we like:
Colour coded braces
Four height choices 4m – 7m
Outriggers standard on 6m and 7m versions
What could be better:
Outriggers not included as standard on 4m and 5m versions
The Home Master DIY aluminium scaffold tower from BPS Access Solutions has a fantastic specification and build quality for this type of tower at this price point. Its welded frames give it great strength and the blue and red colour coded braces make assembly difficult to get wrong. Assembly is quick and easy with the jumbo wing nuts.
The “Tilt and Glide” designed wheels make it easy to move once erected. You simply tilt and lift one end of the tower so the wheels come into contact with the ground and then move it to the next desired location.
For increased stability and safety at greater heights, the 6 and 7 metre variations come with 4 telescopic outriggers as standard. This increases its footprint making it feel rock solid. It would of been a nice touch to add some outriggers to the 4 and 5 metre variations but at the price point, it would of been difficult. They are however available as an optional upgrade.
This tower would complement any keen home DIY’er or ‘jobber’ and because of its availability of four sizes, it’ll suit almost every application from decorating your stairs to painting the outside of your house or even pruning trees.
We have covered quite a bit and if you’re in the market for a mobile access tower, I’m glad that you reached the end of this article and hope that its helped focus your thoughts on some of the important considerations.