A Boulet roof tile is a clay tile with strongly raised edges for better water discharge, laid with a half-tile offset in each successive course. In the Netherlands it is known as a kruispan, and regionally as an Echterpan.
Origin
At the end of the nineteenth century the French manufacturer Boulet of Paris introduced a machine-made tile with a pronounced, art nouveau flavoured shape. In the Netherlands the licence was granted in Echt, in Limburg — hence the name Echterpan.
What makes the tile distinctive
- The laying pattern. Unlike most tiles, these are not laid directly above one another: each course is offset by half a tile, much like brickwork in stretcher bond. That offset gives the roof plane a calm, closed appearance.
- Deep edges and interlocks. The pronounced side interlocks carry water away well and make the tile less prone to wind-driven rain penetration.
- Finishes. It is available unglazed, matt glazed and gloss glazed. On the glazed version the depth of colour strongly determines the appearance of the whole building.
- Fittings. Matching fittings exist for ridge, verge and penetrations; with a half-offset tile they matter more than usual, because the verge detail differs from course to course.
Use today
The tile is now used mainly in renovation and restoration: its distinctive appearance makes it hard to combine with neutral new build, but it is indispensable on buildings originally covered with it.
Points to watch when replacing:
- Check the gauge. Every tile model has its own batten gauge. Never assume the existing battens will suit; check the manufacturer’s covering length and re-set the battens where needed.
- Allow for weight. Clay tiles as a roof covering typically weigh in the order of 40 to 50 kg per m². If you deviate from the original model, check that the roof structure can take it.
- Keep spares. With a tile you cannot pick up at any merchant, a stock against future breakages is worth its weight in gold.
- Half tiles at the verge. Because of the offset, every second course ends with a half tile or a verge tile. Count those separately.
Related terms
- Roof tiles
- Roof tile interlock
- Dutch pantile
- Hollow pantile
- Tile batten
- Engobe
- Roof tile production
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