A light tile is a roof tile with a hole in it covered by a half bell — think of the shape of a Christmas bell — that shields the opening from rain. The tile lets light and air reach the loft without water getting in. In Dutch this type is called a klokpan, and also lichtpan, doevepan or huifpan.
The construction is simple and effective. The hole sits in the face of the tile; the bell stands over it like a hood, with its opening downwards or to the side. Rain strikes the outside of the bell and runs away across the tile, while light and air enter under the lower rim. A version in glass or a transparent material is mainly about light; one with open sides is mainly about ventilation. The nearest English equivalents are a glass or rooflight tile for light, and a vent tile for air.
Where it applies
- Uninsulated roofs without a sarking layer — sheds, stables, barns and old domestic lofts
- Lighting a storage loft where a rooflight or dormer is not wanted
- Ventilating the roof void — removing moisture from a cold loft
- Historic and listed roofs — where the appearance of the tiled surface must stay intact
Points to watch
- Not in an insulated roof — in a warm roof with insulation and a vapour control layer, a tile of this type is a hole in the thermal envelope and in the airtight line. Use a rooflight or a closed vent tile connected to a duct instead
- Birds and insects — an open bell is an invitation; a mesh or grille under the hood keeps nests and pests out of the roof void
- Driving rain in a storm — with strong wind from the wrong quarter water can still get in; do not place the tile directly above stored goods
- Limited light — a single light tile gives very little brightness; usable lighting takes several, spread over the roof slope
- Matching model — the tile has to match the existing tile type in shape and size; a tile that does not match will not weather properly
Practical tips
- Never walk loose on a tiled roof — use a roof ladder and spread your weight; tiles break under point loads
- Check the bell annually — it is a loose component that blows or slides off; look at it separately during the roof inspection
- When replacing — take the old tile to a reclaimed tile merchant; there are dozens of models that are not interchangeable
Related terms
- Roof tile
- Pantile
- Vent tile
- Ridge tile
- Verge tile
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