This is a video showing the fitting of a velux roof window with instructions.
Fitting roof window flashing.
Moving up on to the roof fit the flashing around the frame according to the manufacturer s instructions.
Finally fit the flashing above the frame.
Start by fitting the sill flashing at the bottom of the frame.
Secure the flashing as instructed with nails or roof cement.
All the same rules of flashing apply except only the measurements of chase depth and drop are required.
Then move up the sides of the frame.
This is a video showing the fitting of a velux roof window with instructions.
Roof flashing is a thin material usually galvanized steel that professional roofers use to direct water away from critical areas of the roof wherever the roof plane meets a vertical surface like a wall or a dormer.