Clay and concrete tiles have both become more popular options for residential homes in the United States as manufactures have created better methods of creating these tiles, along with different types of tile that look more appealing on houses. Both types of tile are still most popular in hot, dry climates, but clay tiles tend to last slightly longer than synthetic concrete versions.
* Clay Tiles
Clay tiles are very similar to unglazed ceramic tiles used indoors. Manufacturers take clay, mold it into the shape of roofing tiles, then fire it in a kiln to harden it. The tiles can be either interlocking or overlapping, depending on style, but they are rarely painted and tend to be a dull red color. They are extremely fire and heat resistant, but are also very heavy compared to most roofing options.
* Concrete Tiles
Concrete tiles are made from cement that is reinforced with a fiber substrate. These tiles can be made in a variety of shapes and often mimic existing tiles, such as shingles or panels. They can come in a wider variety of shades than clay, and do not need much maintenance after being installed. They are also fire resistant, though not as much as clay tiles. They tend to be more expensive than clay.
* Lifespan
Clay tiles are extremely durable and have a very long lifespan. They frequently last longer than the roofing materials they are built on top of. Many clay tiles have lasted successfully over a hundred years, and modern versions of clay tile manufacturing have improved. Concrete tiles, on the other hand, tend to last 30 to 50 years. This is long compared to other roofing options, but not as long as most clay tiles.
* Structure
Clay tiles are extremely heavy, and this puts a lot of stress on other parts of the roof under them. This means that even though clay tiles are durable, they decrease the durability of other roofing materials in the structure, which can sometimes require repairs to fix or add support. Concrete tiles are lighter and do not affect the roof structure in the same way.
* Wear
Clay tiles, after they are hardened, are made to be highly resistant to water. Both clay and concrete tiles will suffer in winter conditions where moisture freezes on the roof, but concrete is more porous and will often disintegrate more quickly. This is especially true of older concrete tile rooftops, before more modern coatings and materials were used.
(Source:
http://www.ehow.com)