Onsite

Key steps to selecting site stairways

13 December 2016

Chris Pierce from Combisafe International has some essential pointers when choosing the best temporary access solution.

Falls from height continue to be one of the biggest causes of fatalities and major injuries in the construction industry. Safety managers therefore need to give careful consideration to how they select the best protection, which will allow construction workers to be most productive on site while also reducing the likelihood of an accident.

There are currently several different types of stair access solutions on the market, from the common ladder to the more sophisticated scaffolding/access towers. Another option is the site stairway, which for many reasons is the most practical and cost-effective solution.

Why and how to choose site stairways

In recent years, best practices and increasing regulations have supported the move away from ladders in general construction activities. The Health and Safety Executive states that ladders are the bottom of the hierarchy of controls and that their use may be justified providing it is not reasonably practicable to use other work equipment which will prevent or mitigate a fall.

To start with, construction sites can be incredibly busy and workers are often climbing up and down through narrow areas laden down with tools and materials. To successfully navigate a ladder, workers need certain points of contact at any one time and this is not straightforward when they are ferrying potentially heavy and large objects and trying to grip on the ladder rungs simultaneously.

In comparison, site stairways are designed to enable forward-facing movement, like regular stairs. When selecting a site stairway, ensure that a double handrail is positioned on both sides that can be automatically adjusted to the correct height to meet the angle of the stairs. All temporary stairways used on site should conform to EN 12811, which specifies the rise and going, minimum width, acceptable angles and load capacity.

To provide stability, there must be a locking mechanism, which keeps the stairs at the correct angle. The bottom of the stringers should be designed to prevent slips while the treads should have a coarse non-slip surface to provide added grip. The stability that all these features offer enables workers to move around safely and in comfort.

Site stairways act like normal stairs with handrails on either side

Site stairway designs vary and are usually between 750-800mm wide, which permits occasional passing if workers need to ferry large quantities of materials to and from different levels of a building. While only two people can stand on a single tread at one time, multiple users can pass back and forth. This is simply not an option with ladders. In addition, for high-passage rates, the stairways can be set up in pairs, each for one-way traffic.

Safety managers also need to plan for emergency situations should a worker have an accident or a fire breaks out. Because site stairways provide easy access and egress throughout a building, they are the most practical solution for hastening the arrival of emergency services should they need to come to the rescue. 

Ease of use and flexibility

Quick and easy to install, site stairways within a matter of minutes can be lifted off transport and secured in place at an angle of between 30 and 55 degrees, as specified in EN 12811. Importantly, whatever the angle of the stairway, the treads will always be horizontal to aid safe movement.

Some of the latest site stairways available on the market are manufactured in steel sections with a durable galvanised finish, come in multiple lengths (such as three, six, nine, 12, 15 and 18 steps) and can be joined and supported to offer a single run climb height of up to 7.5m.

Installed externally on a building at ground level, the single run allows workers to gain access into the second floor of a development. However, site stairways can also be used internally to access between floors where there are spaces large enough to install them.

The fact that site stairways can be set up on table forms, in service ducts, around the perimeter and other areas on site means that they can be used to protect a building’s permanent stairs from the wear and tear of the construction process.

Another key benefit of using site stairways is the flexibility they offer. Often on a project, access up through the floors isn’t possible until after the early stages of development. When this happens, construction firms will use scaffolding/access towers externally to enable workers to gain access to the top floors. Site stairways can be constructed within the tower to hasten movement.

Stairways are wide enough to allow occasional passing of workers

Site stairways are also very adaptable. For example, if a construction team was digging a hole into the ground, doing work on a basement or undertaking foundation works, they could continue to add sections to the stairs to adjust to the increasing depth. Importantly, this removes the need to take the stairway out and put a new set of stairs in, saving on time and cost.

The only restriction on the use of site stairways is ground clearance. For instance, if a construction team needed to access up to a height of 3m and the ground clearance was only 1.5m, then it would not be practical to use the site stairways. The angle would be too sharp to use them and in this instance a ladder may be more appropriate. 

However, if the team needed to get up to 3m and there was good ground clearance – say 4-5m, then the site stairways would be ideal. Combisafe provides detailed plans for construction teams, which show, depending on the angle that the stairways are put in, the height and the ground clearance, what site stairways are most suitable for the project.

Cost and application

Scaffolding/access towers are an essential access tool for many developments and can be a good practical solution. They have a wide range of work applications and should conform to EN 12811.

However, for some applications, site stairways are a more suitable solution. Scaffolding/access towers usually require trained installers which can be costly and inflexible. Because there are a lot of components, scaffolding/access towers take up a very large footprint on site until they are assembled, which can be an issue for inner city developments where space is restricted

Transportation is also a factor that needs to be considered. Depending on the size of the scaffolding/access tower, ferrying them to site may require multiple journeys. Taking into account the materials, training needed to assemble them, and transportation, this temporary stair access solution can prove to be very costly for construction firms.

In comparison, site stairways are very easy to install and use. They can be pre-joined to the required length before transportation to site or they can be assembled easily on-site. They can also be folded flat for ease of transport and take up very little room on-site once they are taken off the vehicle.

Two workers can easily install stairways of up to nine steps. They simply fix the top to the upper level with one of a range of attachment devices to prevent movement in use and secure the handrails in place. The bottom of the stringers have points to prevent slipping.

In addition, the stairway units are all cross-braced between the stringers to provide increased stability.

Site stairways have a wide range of applications. However, one area where they can be specifically used because ladders and scaffolding/access towers are not appropriate is on embankments. Even in poor weather when the embankment becomes muddy, site stairways can be securely fastened into the ground. The stairways also have porous steps, which means that rain, snow and mud will not settle and the steps won’t become slippery.

Maintenance and inspections

All temporary stair access solutions should be designed and tested to meet the access performance requirements within the European Standard EN 12811 for temporary works equipment. Make sure that the site stairway comes with an inspection list in the back of the user instructions and that the solution is designed so that anyone can examine the stairs.

Combisafe recommends a fortnightly inspection but some construction firms will do inspections more regularly depending upon their safety protocols. Due to the robust construction of the stairway, very little, if any, maintenance is required.

Chris Pierce is technical services manager UK for Combisafe International, part of Honeywell

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