Clay Roofing

Clay roof tiles are one of the oldest types of roofing materials, dating back hundreds of years. They are made from natural clay that is baked to remove excess moisture, and they may be glazed or unglazed. Clay tile is known for its rich red coloring and its high level of strength and durability. Many different styles and designs of clay roofing are available to complement a variety of decors.

One of the most well known types of clay roof tile is the Spanish or Mission style. This tile has a "U" or "S" shape that creates a distinctive interlocking design. Italian-style clay tiles are made from two components, including a rounded top section and a flat bottom piece.

The bottom unit is laid flat on the roof and uses flanges to keep water off the roof surface. The rounded top portion overlaps the flanges to mimic the look of Mission tile. Flat clay tiles are known as Mangalorean or interlocking units.

Clay and concrete tiles are used as roofing in some areas of North America. With their primary use in very dry and hot climates such as the southwest United States, they may not be your best choice in wet climates as well as in climates subject to freezing temperatures.

Many tiles are extremely porous, allowing them to absorb water. This water causes the tile to fracture, crack, and deteriorate. Tile roofs are installed over under layments that are designed to carry water away when it gets through the tile. However, as the tiles age and crack, more and more water passes through them, eventually wearing out the underlayment.

Clay tile roofs are also prone to supporting biological growth, meaning streaks and stains. Periodic power washing is required to keep the roof looking good. And, each time it is cleaned, more cracks may occur, speeding up the eventual failure of the roof system.

The weight of clay tile roofs can be as much as 12 pounds per square foot, creating a risk of collapse in the event of earthquakes or fires. A life expectancy of 10 - 20 years is common with tile roofs.

Roof tiles are designed mainly to keep out rain, and are traditionally made from locally available materials such as terracotta or slate. Modern materials such as concrete and plastic are also used and some clay tiles have a waterproof glaze. A large number of shapes (or "profiles") of roof tiles have evolved.

Installation

Clay tiles require a reinforced framing and sheathing system to support their added weight. They also require an enhanced waterproofing membrane to keep water away from the roof structure.

A clay tile is not necessarily designed to repel water by itself; instead, it protects the underlayment or membrane from sunlight and weather damage so that this membrane can catch and repel excess water. Most clay tiles are fastened to wooden strips known as battens rather than directly to the roof deck. Flat clay units are often fastened directly to the deck, similar to shingles.

Function

Clay tiles serve both an aesthetic and functional purpose. They can be used to complement many different styles of architecture but are also very effective at protecting the home from exterior elements. The natural air space under these tiles also helps keep the home cool, even in the warmest climates.

Benefits

No matter what type of clay tile is used, homeowners can expect these tiles to last for decades. They are attractive and offer a distinct look that is not possible with other materials. Various diverse designs are available that can be used to enhance a broad array of Spanish- and Italian-inspired motifs, among many others. Because they are made from natural clay, these tiles are also completely recyclable and offer a high level of sustainability.

Challenges

Several disadvantages are associated with clay roofing tiles. They are fairly expensive compared with many other roofing materials, and they are difficult to install. Although some do-it-yourself homeowners may be able to install flat clay tiles, Mission and Italian styles often require professional installation by a contractor experienced with this material.

Roofers cannot walk on these tiles without damaging them, which makes installation and repair challenging. Most types of clay roof tiles are also relatively heavy and may require a reinforced or enhanced roofing system to support their weight.

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