Anti Slip Glass for Walk On Glass Floor and Rooflights

What is Anti Slip Glass?

Let us explain what Anti Slip Glass really is. Glass can become slippery when wet, that part is easy to understand. Common sense should be applied when specifying this material for walk on applications such as walk on rooflights. This is of particular importance when the glass is being installed where the public can access it.

On a private dwelling, it is less likely that the glass will be used if it is raining. However, the same cannot be said for commercial and public applications.

Applying an anti-slip glass surface finish to glass that is designed for walk-on applications should always be considered. The same finish can also provide some obscurity to the glass if required.

A screen-printed frit that includes particles within the ink to create a rough texture can be applied to the glass in a variety of patterns, which will significantly increase the slip resistance of the glass. Alternatively, the surface of the glass can be sandblasted which will result in more diffused light and improved obscurity.

Slip resistance is measured using mean Pendulum Test Values (PTV); the higher the figure the better the slip resistance.

A PTV of 0-24 has a high slip risk, 25-35 has a moderate slip risk and 36+ has a low slip risk. The test is carried out in wet and dry conditions and the lowest figure is obtained when wet.

Generally sandblasted glass achieves a PTV of 50 and fritted glass achieves a PTV of 60, providing better slip resistance than the sandblasted. However, both are well above the threshold of 36 to be categorised as having a low slip potential.

Further information regarding slip resistance can be found at the UK Slip Resistance Group (UKSRG), or to find out more about specifying walk on rooflights by contacting us at

What is minimal glazing?

The current world of architecture and design, efforts are split into two main areas of focus: innovating, and pushing the boundaries of what can be achieved, and enhancing or highlighting structures that already exist. Minimal glazing could be the tool which bridges the gap between these fields.

The question of what type of glazing will best suit a project has existed since glass was first used as a material in construction, and it’s something that architects and designers have had to navigate consistently in their work.

However, through amazing new techniques in glass manufacture and design, many of the limitations that glass used to impose have been blown apart – and minimal glazing plays a big part in this.

What exactly is minimal glazing?

Minimal glazing involves any glass installations, such as windows and doors, which are visually subtle. As technology and techniques have evolved in the world of glazing and construction, it’s now become viable to design glazing which is structurally sound, and aesthetically unobtrusive.

Until relatively recent developments in construction techniques, windows and other glazing solutions usually involved a bulky frame, which was often made from wood. In 1959, ‘float glass’ was developed, which essentially involved cooling molten glass by floating it on a slow-moving bath of liquid tin – a technique that’s still widely used today as the primary method of creating flat glass panels. Until this, the relatively unstable nature of glass production meant that the material wasn’t uniform, and had to be supported within a sturdy (and therefore often visually clunky) frame.

Even with perfectly flat glass now an option, the arrival and subsequent rise in popularity of things like double glazing mean that frames had to accommodate a thick glazed panel. Even with updates to materials (including fibreglass and aluminium), frames remained thick. This wasn’t inherently a problem; but with the arrival of architectural glazing and toughened glass, things changed.

As new methods were developed, such as heat-strengthening and laminating, it became possible to treat glass not purely as a tool with which to let in natural light, or provide a view, but as a construction material in and of itself.

Frames no longer need to be bulky, and in many cases, can be almost completely visually eliminated. This means that a glass installation no longer needs to act as a standalone feature, and can actually highlight or draw attention to other elements in a design or building. By using things like silicone bonding, which effectively eliminates the need for a solid frame between two glass panels, an almost completely uninterrupted effect can be achieved.

Minimal glazing is the term used for any glass installation in a construction which serves a practical purpose – whether that’s to provide a breathtaking view, or shelter you from the rain as you move from one interior space to the next – all without detracting from the other aesthetic elements of a design. Floor to ceiling windows and large sliding glass doors are the optimum of this design ethos.

Do we need planning permission

Some house extensions and renovations can be made to houses without planning permission. This is known as Permitted Development.

For an extension to an existing home to be classed as ‘Permitted Development’ there are a few stipulations:

The maximum footprint of the extension or garden room must be less than half of the land around the house as it stood in 1948. This is with a maximum height of the extension of 4m – this reduces to 3m if the extension reaches within 2m of your boundary.

The maximum length of a rear single-height extension is 3m from the back of the house for attached properties if the residence is detached this is then 4m. If the extension is two storeys the maximum length is 3m.

Side extensions cannot exceed more than half the width of the existing house. Roof extensions cannot add more than 40 cubic metres of space to a terraced house or 50 cubic metres to a detached or semi-detached house.

Basements are usually permitted if the work is converting an existing cellar or basement, as long as it is not going to be used for self-contained accommodations and doesn’t change the exterior appearance of the building.

Garden Rooms are also usually ok and permitted depending on size and location This is as long as you are not creating a self-contained accommodation.

Permitted Development only applies to houses, not flats or maisonettes and some properties in areas with conservation orders will have different rules.

If planning permission is needed it is useful to get pre-application advice from your local council to highlight any potential issues with your application.