On a centre pivot, rotate the sash until the outer face is facing into the room, engage the barrel bolt that holds it in that position, and clean both faces standing on the floor. That reversing action is the reason a roof window on an upper floor never needs a ladder outside, and it is the single most useful thing to know about owning one.
The reversing action
What makes the whole job possible.
A centre pivot sash rotates about hinges at the middle of the frame, so at a hundred and eighty degrees the outside face has come round to where you are standing.
It is designed for exactly this and nothing about it is a workaround.
The barrel bolt
The part people do not know is there.
Once the sash is reversed, a small bolt in the side of the frame drops into the sash and holds it, so it cannot swing back while you have both hands on a cloth.
Using it is the difference between a safe job and an awkward one.
What to use on the glass
Warm water and very little else. Water with a drop of washing up liquid and a soft cloth or a squeegee handles almost everything, and a second pass with clean water stops it drying streaky.
Cleaning on a cool overcast day is easier than in direct sun.
What to avoid
Abrasives, blades and solvents. A scouring pad, a scraper or a strong solvent will mark a coated pane and can damage the seals and the finish around the glass.
Nothing on a roof window needs more than a cloth.
Self cleaning coatings
Common on roof windows and they change the routine rather than removing it.
A coated outer pane uses daylight and rain to break down and wash away deposits, and it wants cleaning far less often, with plain water rather than detergent.
How the coating works is on what is self cleaning glass.
How often
Twice a year is plenty for most positions.
A window under a tree, on a road frontage or near the sea will want it more often, because leaf fall, traffic film and salt all build faster than ordinary dust.
Salt on a coastal elevation
Worth doing deliberately across our area. A window on a south facing seafront elevation collects salt that dulls the glass and works on the external finish, and rinsing it off is more useful than polishing it.
What that exposure does is on Goring by Sea.
The drainage channels
The thing to clean while the sash is reversed.
The frame carries channels at the sill that take water away from the timber, and when they silt up with dust and moss the water sits where it should not.
A cloth and a soft brush is all it takes, once a year.
The ventilation filter
The other item that only gets done when somebody knows about it.
A filter behind the trickle vent in the head of the sash clogs with dust and salt, and a clean one makes a real difference to a bedroom overnight.
It pulls out and rinses under a tap.
The sash seal
Wipe it while you are there.
A gasket kept clean compresses evenly and lasts. One carrying years of dust and, in a bathroom, soap film, does not seal properly and eventually takes a set.
A top hung sash
Cleaned differently, and it is worth knowing before choosing one.
A top hung window swings out from the top rather than reversing, so the outer face is reached by leaning out rather than by bringing it inside.
Many top hung units still rotate for cleaning, and it is worth checking that on the specific product.
A window above a stairwell
Where reversing does not help.
Where there is no floor beneath the window to stand on, no amount of rotation puts the glass within reach, and that is a job for a pole system or somebody with proper access.
An out of reach window generally
Worth thinking about at specification.
A window high on a vaulted ceiling will be cleaned rarely whatever the intention, which is an argument for a self cleaning coating and against a fussy blind.
The external cladding
Rinsed rather than polished.
The aluminium capping around the frame collects the same dirt the glass does, and clearing moss from above the head of the window helps the flashing as much as the appearance.
Moss and leaf litter above the window
The maintenance nobody thinks of as window cleaning.
Debris collecting on the covering above a roof window dams water at the head flashing, which is exactly where a leak starts.
Clearing it is worth more than the cleaning is.
A lacquered timber sash
Cleaned with a damp cloth, not with anything wet.
Water sitting on a lacquered finish will eventually get into a break in it, so timber is wiped and dried rather than washed.
Checking the lacquer while cleaning is how it gets recoated before it needs stripping.
Blinds while you are there
Two minutes and it fixes a stiff one.
Side channels and guide wires collect film, particularly in a bathroom, and a blind that runs badly is almost always dirty rather than broken.
Children and the reversed sash
The safety point worth stating.
A reversed sash held on the bolt leaves an opening, so it is not a job to leave half done in a room where a small child is about.
Most units also carry a ventilation position that opens the window without unlatching it fully.
What we show you on a VELUX
We show people the barrel bolt and the filter at handover, because both are on every window we fit and most owners have never been told either exists.
The rest is on the VELUX window 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.