By: Kevin Duffy
In this second part of a three part series on steep slope roof systems, we will outline clay and slate tile roof systems. The two systems vary in their historic uses, however, both are considered historic roofing materials and both can be very expensive to install. Due to the high costs associated with their installation, these types of roof systems are typically seen only on historic structures in the United States. You may have seen a slate tile or clay tile roof on an old estate or a historic house of worship. However, in Europe, particularly the Mediterranean, clay tile roofs are predominant.
Clay tiles are considerably older than their slate counterparts, dating as far back as 3000 B.C in Greece. The earliest known slate roof was installed in 1287 in North Wales, England. In the United States, installation of these system was at its peak during the 18th and 19th centuries The fireproof properties of these systems, along with the aesthetically pleasing appearance, made them very popular.
The pros of the clay tile and slate are similar to those of asphalt shingles, however because the clay tiles and slate are more fragile than their asphalt shingle counterparts, it is generally recommend that traffic be extremely limited to roofs comprised of these systems. Clay tiles are molded and come in a variety of shapes and colors. Varying the color blend of the tiles being installed can be a great way to enhance the look of your building, all while providing a great return on investment. Since slate is a naturally occurring rock, the Building Owner is limited in the color selection to the colors that are found in nature, often being duller in color than their clay tile counterparts. Both roof options can be very heavy and may require adding structural supports to the existing roof deck. As previously mentioned, both systems are inherently fire retardant, however, because these systems are often installed over wood decks, their fireproof qualities are compromised. With the proper care and maintenance, both slate and clay tile roof systems can last for hundreds of years.
The flashing and underlayment options of clay and slate tile roofing systems are the same as with asphalt shingles. However, the warranty options are generally for longer periods of time, typically 75 years.