A glazed roof tile, in Dutch a lichtpan, is a roof tile with a transparent panel set into it — traditionally glass, nowadays often impact-resistant plastic. It replaces one ordinary tile in the roof plane and lets daylight into the space below at that point.
The glazed tile is the simplest and cheapest way of getting light into a dark roof space: nothing has to change in the roof structure, no opening has to be cut and no frame has to be set. You take out one tile and lay another in its place.
What is it for?
For an unlined or unoccupied space where you can see nothing without artificial light: an old loft, a storage floor above a barn, a void above a garage, the space under the tiled roof of an extension. Enough light to move around safely and find something.
What a glazed tile is not: a substitute for a roof window. One tile is a small area, usually a few hundred square centimetres of glazing. For a habitable room you need a roof window; glass tiles will not get you there.
Where it does not work
This is the mistake most often made: a glazed tile does nothing in an insulated, internally lined roof. If there is an underlay, boarding, insulation and an internal finish below the battens, the glazed tile only lights the narrow cavity between tiles and underlay. In the room below you notice nothing at all.
If you do want light in a finished roof, the whole build-up has to be broken through — and then a roof window or a sun tunnel is the right solution, not a glazed tile.
Fitting
- Buy the glazed tile in the same model and from the same maker as the rest of the roof. Tiles of different models do not interlock; a tile that does not match is a guaranteed leak.
- Reckon on several. For usable light in a loft you will soon need a few, spread across the roof plane rather than grouped together.
- Choose the position with care. Not directly under a tree (dirt, moss), not in a valley or right beside a chimney, and preferably on the north or east side if you want light without heat.
- Fix it down. A plastic glazed tile is lighter than a clay one and therefore more prone to wind uplift; use a tile clip or screw it as specified.
Points to watch
- Condensation and dirt. The panel mists and soils faster than a roof window, and nobody cleans it. Expect the light output to fall noticeably after a few years.
- Plastic ages. A plastic panel can yellow and become brittle; glass keeps its clarity but breaks more easily.
- No ventilation. A glass tile gives light, not air. If ventilation is also wanted, a vent tile or a hooded light tile (klokpan) is the right product.
- Work safely. Even replacing a single tile calls for a ladder with a ridge hook, fall protection, and no walking on the tiles.
Related terms
- Roof tiles
- Vent tile
- Roof window
- Dome rooflight
- Roof boarding
- Light transmission
Want to know more about building terms? Take a look at our knowledge base on fredsdiyplans.com.