Why Important
Early rooflights simply consisted of a large sheet of thick glass set into the roof like a large slate. It is very unusual to find these now. Later, cast iron pattern rooflights were introduced which need to be painted periodically. They often used as an alternative to using Cupolars for natural lighting of common staircases.
What to look for
Glass can crack due to impact or movement (for example due to timber rot) or if a piece of glass slips.
Timber rooflights with lead flashings are also found, and these need to be checked to ensure that the paint and flashings protecting the timber are sound.
When to look
How to fix
Modern double- glazed metal-framed rooflights, designed to traditional proportions, are now available from several manufacturers, but it is preferable to reinstate a rooflight in the original materials and proportions.
Modern safety glass should always be used when replacing a pane or reinstating a rooflight.
Ensure that the paint and flashings protecting the timber are sound and painted periodically in grey or a colour to match the roof colour.
Avoiding creating problems
Regular visual checking from inside the building can guide you to seeing problems with water penetration.