Terracotta Clay Tile Roofing
Clay was used as roofing for almost as long as roof were built.
“It can be traced back to roofs in ancient China and the Middle East as early as 10,000 B.C.,” says Adam McCoy, president of McCoy Roofing.
“The style of clay tile known as ‘Terracotta’ has been around almost as long.”
While terracotta tiles fit almost any architectural style, they’re usually associated with architectural styles like Spanish Mission and Italianate Villa.
Terracotta clay tiles are crafted from molds filled with fine, wet clay. The molds are fired at a high temperature in a kiln to create a tough surface.
The time and temperature in the kiln determine its density. Finished tiles are waterproof, weather-resistant and fire-resistant.
“Clay tiles are prominent used in Mediterranean climates,” Adam says, “but they also work just as well in Omaha and the Upper Midwest.”
Use and longevity
Clay tile roofing works best on slopes of more than 20 degrees. The steeper the slope, the more visually defined the clay tiles become.
Clay tile roofing has the following advantages:
- More reflectivity due to its red hue
- Clay tiles reflect and shed radiation
- Anything not reflected still gets pushed away, but at a slower rate. This shedding of radiation is called “emissivity.”
- Tile roofing can cut heat transfer 70% more than other roofing materials.
- The tiles remain up to 70 degrees cooler than roofing materials like asphalt that can reach 190 degrees.
“Clay tiles offer a 50- to 100-year lifespan and need little maintenance,” Adam says. “They’re easy to recycle and environmentally friendly.”
Clay tile installation requires experienced contractors. If leaks occur, damage can result to the underlying structure. The tiles are heavy and breakable, and need careful installation. Weight distribution is a serious planning consideration.
3 grades of clay tiles
Adam says there are three grades of clay tiles used in roofing.
Grade 1 clay tiles, also known as mission and barrel tiles, consist of two pieces of clay with pans and covers. They’re usually high-profile with a rise-to-width ratio more than 1:5. Grade 1 clay tiles are either straight or tapered. They are non-porous and maintain through cold conditions resulting in freeze-thaw cycles.
Grade 2 clay tiles or S-tiles are characteristically low-profile with a rise-to-width ratio of 1:5 or less. They are commonly seen in Spanish architecture and recognized by their high curve. Slightly more porous, they’re less water-resistant than Grade 1. But they hold up through freeze-thaw cycles.
Grade 3 tiles include any other type of tile, including flat tiles (also known as English shingle or Closed shingle) that butts into other tiles or has interlocking edges. They’re recommended for areas with mild climates. Grade 3 tiles are more porous and may not hold up in freeze-thaw cycles.
Types and Styles
Barrel clay tiles are characterized by their barrel-like shape. They are divided into two categories – Mission and Spanish.
- Mission-style tile is also known as high-profile barrel-style tile. It’s installed to create shadows for texture and style. It measures between 8 and 12 in. wide and 16 to 19 in. long.
- Spanish tiles, with their rippled appearance, look like mission tiles but are constructed in a single piece. This makes them easier to install. They come in three sizes: 13 x 16 ½ in., 8 ¾ x 11 in., and 9 x 14 in.
- Interlocking clay tiles offer ease of installation with a variety of sizes, textures, and profiles.
Interlocking clay tiles offer ease of installation with a variety of sizes, textures, and profiles.
- French tiles are built with deep interlocking tabs on all four sides and two flutes that produce shadows for additional drainage and dramatic appearance. French tiles measure 9 x 16 ¼ in.
- Shake clay tiles look like original wood shake shingles but need less maintenance and have a much longer lifespan. They’re available in multiple styles.
- Slate clay tiles offer the beauty of natural slate shingles. But they’re easier to install, less expensive and come in various sizes.