#TERRACOTTA ROOFS INSTALL#

The assemblies were exposed to firebrand showers generated by the NIST-developed firebrand generator. In the new research, Manzello studied roof assemblies made of flat and profiled (wave-like) cement and terracotta tiles. This hypothesis, Manzello says, requires further investigation.

#TERRACOTTA ROOFS INSTALL#

The research findings suggest that one potential approach to reducing wildfire risks would be to install continuous, fire-resistant underlayments. This infiltration of embers through gaps, he explains, ultimately could lead to ignition of materials in an attic space immediately below. In an earlier study,** Manzello and colleagues simulated this effect and observed greatly reduced performance of ceramic roofing assemblies as compared to well-aligned Spanish tile roofing assemblies. 'Over time, gaps can develop in roofing assemblies due to settling of the structure, aging of the materials, earthquakes or other causes,' he says. Manzello cautions, however, against a false sense of security with this type of roofing assembly. For these tiles, the firebrands were observed to become trapped within the interlocking sections of the tiles and, as a result, the firebrands did not penetrate past the tiles towards the underlayment. Of the four roof styles studied, the flat tile terracotta roofing assembly performed best probably due to its interlocking design.

In scoping experiments conducted in the Fire Research Wind Tunnel Facility at Japan's Building Research Institute, NIST fire scientist Samuel Manzello found that the embers-or firebrands-infiltrated gaps between certain types of roofing tiles and, once trapped, proceeded to melt the underlayment below. Although made of fire-resistant materials, terracotta and cement roof tiles are vulnerable to penetration by windblown embers generated in wildfires, according to new research findings* from the National Institute of Standards and Technology (NIST).

Terracotta roofs