One of the more interesting architectural features of many buildings is a turret - imagine the conical roof on the round corner of a medieval castle and you'll know exactly what we're talking about. 
There are typically two (but certainly quite a few more possibilities exist) types of turret roofs: round and segmented.
- Of these two types, round turrets pose the most problems for roofers because most roof materials are intended to be installed in horizontal rows. Unfortunately, while a round turret roof can be roofed in horizontal rows, each row is a different length. As a result, the roofer is put in the pickle of either having to customize the size of each piece of roofing material so his pattern stays intact as he installs each decreasing-long row, or he can just give up on the aesthetics of symmetrical rows and have offset (aka: "ugly) patterns.
- On a segmented turret roof, the series of triangles or "pie slices" that make up the roof offer the roofer many more choices because he can keep his vertical rows intact and terminate them at the resulting hips. It's a much busier look, but easier to make symmetrical.
Of all of the roofing materials that can be used for turret roofs, metal offers the most variety, and in many cases the most suitability. Metal roofs with converging, vertical ribs (like the picture below), can be created with many types roof turrets. And there's a bevy of material choices, like copper, zinc, steel or aluminum, plus very exotic materials like stainless steel, bronze, titanium or even silver or gold roofing. All have been used on turret roofs around the world.
To summarize:
- Turret roofs come in a few different shapes but are most commonly conical or segmented
- Turret roofs are very difficult to cover with most roofing materials
- Metal is usually the best choice for roofing and waterproofing all types of turrets
- Metal roofing materials for turrets can be made of copper, steel, aluminum and other metals.
