Warm water, a mild detergent and a soft brush, rinsed off properly. A walk on panel wants cleaning more often than an ordinary rooflight because it is walked on, and the reason is grip as much as light: a film of algae or grime on a wet panel is what turns a well specified anti slip surface into an ordinary slippery one.
How often
Several times a year rather than annually.
A terrace panel collects foot traffic, grit, pollen and leaf residue, and a shaded one grows a film between cleans, so three or four times a year is realistic.
Why grip is the reason
Because the surface only works clean.
A fired frit or an etched finish gives grip through texture, and a layer of algae over that texture fills it in and undoes it.
How it works is on is walk on glass slippery when wet.
Why light is the other reason
Because the room below depends on it.
A basement lit through a dirty panel is noticeably darker, and the difference between a clean and a neglected panel is obvious from inside.
What to use
Water, and very little else.
Warm water with a mild detergent and a soft brush handles nearly everything, and the important step is rinsing thoroughly afterwards.
Why rinsing matters
Because residue is the problem.
Detergent left on the surface leaves a film that attracts dirt and reduces grip, which is exactly the condition you were cleaning to remove.
What to avoid
Anything abrasive or waxy.
A scouring pad marks the surface, and a polish or a wax leaves a slippery film on a floor, which is the least helpful thing available.
Pressure washers
Use with care, or not at all.
High pressure aimed at the perimeter drives water past gaskets and can lift the edge of a drainage detail, and on a buried kerb that is worth avoiding.
The perimeter channel
As important as the glass, and usually forgotten.
The drainage channel around the panel fills with grit and leaves, and once it is blocked the water sits at the junction the design was keeping it away from.
Why it matters is on do walk on rooflights leak.
Clearing it
A brush and a few minutes.
The channel is cleared of debris and flushed with water to check it discharges, and that is worth doing every time the panel is cleaned.
The terrace outlets
The other thing to check while you are there.
A blocked outlet turns a terrace into a shallow pond, and the panel and its junction are standing in it until it drains.
Algae and green film
The commonest complaint.
A shaded panel grows a film that is slippery and unattractive, and it removes with a brush and water rather than needing anything stronger.
Where a treatment helps
A biocidal wash, occasionally.
Where growth returns quickly, a proprietary algae treatment suitable for glass and rinsed properly extends the interval between cleans.
Bird mess
Dealt with promptly.
It is acidic and it etches over time, and it is far easier to remove within a day or two than after a season of baking on.
Scratches on the surface
Expected, and that is what the layer is for.
Years of grit underfoot mark the sacrificial top pane, and those marks are cosmetic rather than structural.
What that layer does is on what happens if walk on glass breaks.
Whether scratches can be removed
Not usefully, and it rarely matters.
Polishing out a scratch on a textured anti slip surface would remove the texture, which is a worse outcome than the scratch.
Cleaning the underside
Occasionally, from inside.
The room side face stays clean far longer, and reaching it means working at height inside the room, so it is done rarely and deliberately.
What a fritted panel hides
More than a clear one.
A patterned surface disguises marks and dirt where a clear panel shows every one against the sky, which is a practical argument for a frit.
The options are on can you see through a walk on rooflight.
Cleaning around the paving
Where the grit comes from.
Sand and grit from jointing and from the garden is what abrades the surface, so sweeping the terrace regularly does more for the panel than cleaning it does.
Safety while cleaning
A wet panel underfoot.
The surface is at its most slippery while it is being washed, which is worth remembering on a terrace with an edge.
What a service look covers
Surface, channel, outlets and seals. Cleaning the glass, clearing the drainage, checking the outlets and looking at the perimeter gasket is the whole of what a walk on panel asks for.
When to do it in the year
Spring and autumn, at least. Spring clears the winter film before the terrace comes back into use, and autumn clears the leaves before they block the channel through the wet months.
Before a party or the summer
The practical prompt. A terrace about to be used barefoot by people who have had a drink is the moment the grip on that panel matters most, and it takes twenty minutes.
Whether a window cleaner will do it
Usually, and it is worth asking specifically.
Most will clean a terrace panel as part of a round, and the perimeter channel is not something they would think to clear unless it is mentioned.
What we show you on walk on glass
We show people the perimeter channel at handover, because it is the part of a walk on installation that decides whether it stays dry and nobody would guess it was there.
The whole picture is on the walk on rooflight installation page.
Thinking about this job? We survey across Worthing, West Sussex and the South Downs and give you a fixed price before any work starts, with a 10-year workmanship guarantee.