Tile is a highly attractive and non-combustible material that is popular for roofing on Southwestern and Spanish style homes. Coupled with stucco siding, this type of home has an excellent fire safety rating. However, mistakes in construction and maintenance can make a tile roof less of a barrier against flames than it would otherwise be. Basically, anywhere there is a crack or other hole in the clay material there is the potential for a fire to gain a foothold.
Consider a classic barrel style clay tile roof. Each tile is round on top and open on the end. They are overlapped to make a solid roof. However, at the edge the tile is open to penetration. Embers that are blown into these openings can catch the roof underlayment and wood structure on fire. There are caps called “bird stops” that should be used to close off these apertures as part of the installation process.
As the name suggests, these bird stops are intended to keep feathered intruders from creeping under the clay tiles to make nests. Since nest materials are generally highly combustible, they present an additional fire hazard. The bird stops should be checked regularly (for example, twice a year when you check your gutters). They may become dislodged and require re-affixing to restore the integrity of the clay tile roof.