The short answer
Open the sash, swing it round until the outer pane faces into the room, and lock it in that position using the catch your model provides. Wash the glass with soft cloths and mild soapy water, wipe the seals gently and close the window again once it is dry. Every model differs a little, so follow the current VELUX instructions for yours.
Why the outer pane can be reached from inside
A roof window is often out of arm's length from the garden, and nobody should be out on a slope with a bucket. The maker's answer is a sash that turns.
On many VELUX roof windows the sash pivots on hinges set around the middle of its height. Push the lower edge of the open sash up and the whole pane turns through half a circle, so the side that faced the weather now faces you. The clever part is that the sash then holds itself there. A catch or lock engages in the cleaning position, so the frame is not swinging back at your fingers while you work.
That rotating action is what people mean when they search for how to rotate a VELUX to clean it. It belongs to centre-pivot models. A window that is hinged at the top and only opens outwards does not turn over in the same way, so the approach differs, and our explainer on the GGL, GPL and GGU types shows why the action changes between them. If you are unsure which you have, the label on the frame tells you, and where the data plate sits is covered on its own page.
Electric and solar models are a separate case, since the controller must be handled correctly. Read the instructions for the model before you open or move anything, and see VELUX INTEGRA electric roof windows for how those behave.
The cleaning, step by step
Choose a dry, overcast day if you can. Direct sun dries soapy water too fast and leaves streaks, and a cold pane is kinder to the cloth than a hot one.
- Clear the space. Move the furniture and lay a towel under the window. Water will run down the glass and along the frame.
- Open the window. Use the handle or control bar at the top of the sash, as your model describes, and lift the sash until it stops.
- Turn the sash. Hold it with both hands at the sides. Swing it over slowly until the catch engages. Check that it is locked before you let go.
- Dust first. Wipe the dry pane with a soft cloth or a soft brush to lift grit that would otherwise scratch when wet.
- Wash. Use a clean cloth or a soft sponge with warm water and a small amount of mild washing-up liquid. Work from the top down.
- Rinse and dry. A second cloth with clear water, then a dry microfibre or a squeegee with a soft edge.
- Return the sash. Release the catch as instructed, turn the sash back and close it without letting it drop.
Take your time with the turn. The sash is heavier than it looks, especially with laminated or triple-glazed units, and it should be guided, not flung.
Looking after what is around the glass
While the sash is open, you are looking at parts that are normally hidden. It is worth a minute to look at them.
The rubber seals run round the sash and the frame. Wipe them with a damp cloth to remove grit and grime. Dirt trapped in a seal stops it closing evenly, and an uneven seal is one of the quiet ways a window gets noisy, with a whistle in wind or a thin rattle in rain. The cleaner they are, the better they close. If a seal looks split, flattened or hard, that is not a cleaning job. It is a sign the parts should be renewed, and the next section explains how that connects to a new sash.
The finish on the inner frame depends on the model. Pine is lacquered, while the white versions are painted or coated in polyurethane, and each wants mild treatment. Use a damp cloth, no solvents and no abrasive pads. The page on VELUX pine, white painted and white polyurethane finishes explains the difference.
Finally, glance at the ventilation flap above the sash, which is where fresh air enters when the window is shut. Brush out dust and any insects so it stays clear. Our page on the ventilation bar and handle explains how that part works.
| Part | Use | Avoid |
|---|---|---|
| Glass | Soft cloth, mild soapy water | Scourers, blades |
| Seals | Damp cloth | Oils, solvents |
| Pine or white frame | Damp cloth, dry off | Abrasives, strong cleaners |
| Blind in its channels | Soft brush | Soaking |
When cleaning is not the answer
Some marks do not wipe off, and it helps to know which ones are telling you something.
A film that stays between the two panes of glass, cloudy or beaded with moisture, is inside the sealed unit. No amount of washing will reach it. That unit has failed, and the answer is to replace the sash or the window, which we explain in misted and failed rooflight replacement. Check whether a new sash is possible in can a VELUX sash be replaced without changing the frame.
Seals that stay hard or flat after cleaning, a sash that no longer shuts flush, or a frame with soft timber at the base are the other signs. A window near the end of its life is covered in how long a VELUX window lasts. When a new one is the right call, the quiet spec records the glazing and seals we propose for the room. To talk it through, use the quote form. The wider range we install is on our VELUX window installation page.
Small questions about washing a roof window
How often should I clean the glass?
Whenever it looks dull from inside. A window under trees or near a busy road collects more grime than one facing open sky, so there is no fixed interval.
Can I use window-cleaning spray?
A gentle glass cleaner is fine on the pane, but keep it off the seals and the timber or painted frame. Plain warm water with a drop of washing-up liquid does the job for most marks.
Does self-cleaning glass mean I never wash it?
No. A self-cleaning coating helps rain carry dirt away, but the inside face still gathers dust and the coating should not be scratched. Wash it with soft cloths, as above.
Do blinds need cleaning as well?
A light dust with a soft brush is usually enough. For the choice between types, see choosing genuine VELUX blinds.