Would it surprise you to hear that 80%+ of entrances to buildings are fundamentally unsafe? Most building owners and managers probably would expect that theirs is fine, so why have most buildings got it wrong? Given this knowledge, how do you know if your entrance system is effective or not?
Whether or not someone slips over when they enter your building comes down to just the entrance system. By that we don’t just mean is there a small entrance mat, but – working from outside the building to in –, a canopy if you have one, the door or doors, the matting on the floor surface, and the floor surface itself including how that is cleaned and maintained. Often people feel they have an effective entrance system despite only ticking the box in only one or two of these areas – as with many things in the world of slip safety, a superficial view is commonplace.
Other factors do come into play if you consider our CHIMES model. For example, if the entrance is used by staff and you are able to provide them with slip-resistant footwear, this would significantly lower the risk of a slip. People factors is another: if, inside your building, there is a large TV screen showing something, this could distract people stepping inside, causing them to not notice changes in floor types, or to stop them from spotting a potential hazard such as a spillage on the floor.
Critical, though, is the question of what is in your control. Looking at the management of slip safety risk holistically and from a building owner or operator management perspective, the factors in the entrance system mentioned above are all that are controllable for you with any certainty.
The simple way to tell whether your entrance system is working (without any rigorous, specialist advice or analysis) is by standing inside on a wet day. If you can see water on the floor beyond the matting, whether footprints or drops of water, that suggests that your entrance system is ineffective. Remember:
- The whole point of having the system in the first place is to prevent your floor from becoming wet or contaminated.
- Water can come into your building in all sorts of ways, not just on people’s feet. Particularly on very rainy days, you might have hats, coats, bags, luggage, pushchairs and, of course, umbrellas, carrying water that can drop onto the floor. These would not touch the matting (designed to dry your feet).
- It only takes the tiniest amount of liquid to cause a slip.
“It takes several footfalls with each foot to effectively dry a pedestrian’s shoes.” (HSE)
Bearing this in mind, does this constitute an effective entrance? Will a persons’ feet be dry by the time they get inside?
Let’s go on a journey into a building, starting externally, to walk through the various aspects of an effective entrance system so you can learn what you need to do to ensure users of your building are safe.
An external canopy positioned above the entrance will have – if designed properly – the effect of preventing any rainwater falling too close to the building’s entrance. Even very small canopies, with minimal depth, can be seen to have this effect. For example, see the photograph below:
Whilst in that instance the effect on reducing the risk of slippage is only minimum, if you had the same kind of a canopy that extended 50 metres from the doorway, you could fairly confidently say that the risk of slipping was as close to zero as to be almost impossible. Now that’s somewhat facetious because a canopy will never extend that far, but every 50 centimetres of canopy will help your cause of keeping your entrance floor dry.
In terms of canopy design, some things to think about include:
- The depth of the canopy, as mentioned above.
- Its height. If it was positioned very high above the doorway, this increases the likelihood of rainwater being able to get close to the door in windy conditions.
- You should certainly think about the prevailing wind direction too, therefore, when coming up with your design.
- The type of floor on the outside of the building can also have an effect. If you have a smooth, homogeneous surface, upon which water was collecting and therefore you effectively were walking through puddles just before you enter the building, your feet are going to be wet. Whereas if you had a porous surface where water could potentially seep away from the surface, that’s going to probably leave less liquid on your foot.
Next on a person’s entry into the building comes the door (or doors). There are all sorts of health and safety issues to potentially confront when it comes to door design. Specifically, thinking about sliding doors and revolving doors, incidents have been seen over the years of malfunctions causing injury. But we are looking at this from the perspective of what can be done to mitigate slip risks specifically.
Anything that slows someone down or stops them before they enter the building gives more time for liquid contaminants to be displaced from their feet, clothes, or any items they are carrying.
From a slip safety perspective, a revolving door is likely to give you a better chance of someone’s feet staying dry because they are having to take longer plus make more steps between the exterior of the building and when they step onto your entrance floor.
Sliding doors with an automatic release caused by a sensor are likely to have little to no impact on slowing down a person’s entry to the building.
Those that require manual opening, clearly, will need someone in most cases to physically stop, stand still, and open the door before they proceed.
If you can have two doors, that effect is amplified. The second door, in this scenario, probably even plays a proportionally greater role than the first in mitigating the risk of slipping.
Side doors can often be found in offices, hotels etc to offer disabled access supplementing a main revolving door. Often these doors are given a lower priority and therefore the surrounding infrastructure like canopies and matting are less effective compared to the main door. Try to avoid this.
Walking past building after building all over the country, I am confronted with inadequate entrance mat after inadequate entrance mat. How can I tell this? Simply by a mat’s size. As mentioned above in the quote from the HSE, several steps per foot is required to adequately dry one’s feet. And yet we see supermarket convenience stores with matting that is only, perhaps, 70cm maximum. How is that going to dry customers’ feet?
The HSL (part of HSE) and the Entrance Flooring Systems Association produced joint guidance on the depth of matting required based on the peak footfall of an entrance. With less than 80 people per hour using an entrance this is classified as low use. 400 people per hour is medium use. 800 people per hour would be deemed as high use. The depth of matting required is as follows:
|Usage||Peak traffic per hour||Depth of matting required|
Now I must confess, I have been in hundreds of buildings that have high usage and can count on one hand the number of times I’ve seen matting even approaching 8 metres of depth. I’ve been tens of thousands of buildings overall and very, vert few come close to achieving the minimum requirement even for low usage.
The position of matting is important too. Look at the below example. On the face of it, you’d think the matting is more than sufficient. However, if you enter the building through the left-hand door and immediately turn to your right, you will only benefit from one or perhaps two steps per foot on the mat:
The other key factors that drive mats’ effectiveness are the material they are made of and how they are maintained.
Mats can be made of different materials and this will drive their effectiveness and durability. Mats made of a man-made substance are likely to be much more durable, to require less maintenance and to be cheaper to purchase. Mats made of natural materials, conversely, are likely to be more effective at removing contaminants to dry users’ feet, but will require more maintenance, will have a shorter lifespan and are probably more expensive to purchase.
The way mats are maintained has a big effect on their effectiveness too. We see many mats which are clogged up with grease, chewing gum and other contaminants. This will dramatically reduce the ability to remove contamination and dry a person’s shoes. A proactive, planned preventive maintenance regime should be put in place to monitor this and prevent the mats reaching the point at which it’s no longer helping
“Loose mats can introduce a range of hazards and are not always very effective. Extra matting should be considered a temporary fix, not a permanent feature. At the first opportunity improve the entrance design.” (HSE)
Coupled with inadequate fixed matting, or sometimes even in cases with no fixed matting at all(!!), temporary maps can often be seen laying on the floor close to an entrance door.
This is a great sign that your entrance system isn’t effective. Because if your floors were not getting wet, beyond the built-in matting or without any built-in matting, then there’s no reason to even consider putting in temporary mats.
So, taking HSE’s point about a temporary fix, how many buildings have you visited where day after day, month after month, year after year you see temporary mats. Indeed, there is a huge business in renting these out which is perhaps why the message that they should be used temporarily only has not got out correctly.
Temporary maps have the same challenges as built-in matting in terms of composition, and its effectiveness, as well as maintenance.
But they also introduce some other potential issues:
- Typically, they are rectangular shape placed perpendicular to the built-in matting irrespective of the prevailing direction of travel upon entering the building.
- These mats almost always end up in a different location from where they were placed at the start of the day. This leaves the floor surface exposed, it then becomes wet and may cause a slip.
- Trip hazard. Temporary mats are prone to their corners lifting and causing a tripping hazard. There are some suppliers that have developed versions which are semi-permanent: they stick to the floor, using a kind of adhesive, and typically will stay in place for around eight to 12 weeks before needing to be replaced.
The last point on temporary matting is that it’s unsightly and really does spoil the aesthetic of entrance areas, which, certainly in high-end office buildings, hotels, etc are designed to achieve a certain ambiance. A dingy, great mass of mats spread across a beautiful, polished natural stone was not what the architect had in mind.
Entrance floor surface:
Lastly, comes the floor surface itself. Now if the other aspects of your entrance system are working perfectly, there is an argument to say that the slip resistance of the entrance floor is practically irrelevant because the floor will not routinely get wet. I tend to agree but the problem is – as mentioned – people assume their entrance system is effective when it is not and therefore, they should often have more slip resistant floor surfaces than they do.
It’s important to consider both the inherent slip resistance of the floor surface, and how this is maintained over time, primarily through cleaning practices to achieve a sufficiently low potential for slipping in wet or contaminated conditions.
Using the HSE approved pendulum test, you require a pendulum test value of 36+ to achieve a low slip potential when wet.
In our analysis of 300+ entrance areas in London, two thirds did not achieve this level.
Why is this? It could be down to a misunderstanding of this whole topic. Therefore, an inappropriate floor was chosen during the specification process. For example: “we’ve got an entrance mat so that’s fine; we don’t need to worry about the floor”.
It could be that a good floor was installed but it has changed over time. Typically in this environment that would be caused by one of two things:
- The way it’s been maintained. A textured floor that is cleaned ineffectively will see contamination start to smooth its microroughness away. A surface that has a topical polish applied now had a barrier between it and one’s foot.
- All surfaces will change over time as they are trafficked. A textured natural stone will wear differently to a smooth vinyl.
You need to be aware that you can’t rely on an out-of-the-box slip resistance test; you must monitor this over time.
Do you need PTV 36+ in both dry and wet conditions, though? To answer that question is not as simple as yes/no. You should consider all the points raised within this document about the entrance system, but also work through our CHIMES model to deeply understand the various factors in play.
As a rule of thumb, though, if you do not have a canopy and you do not have 8=10 metres in built-in matting then I would strongly suspect that you are at least in part reliant upon your floor surface to mitigate the risk of slips. As such, I would seek to achieve at least a moderate slip potential when wet (PTV of 26+).
What to do now?
If you have an existing entrance you now know the things to look for.
If you are indeed relying on the slip resistance your entrance floor, you should get a pendulum slip test undertaken to ascertain both the inherent slip resistance values but also the effect that cleaning is having. Any remedial action could then be advised upon.
Conversely, you are designing a building or looking to do a refurbishment of an entrance, you now have a framework to use to design an effective entrance system to better mitigate risk.