Particleboards (PB) and oriented strand boards (OSB) are commonly used materials in building structures or building interiors. The surface of boards may hence become directly exposed to fire or radiant heat. The aim of this paper is to evaluate the behaviour of uncoated particleboards and OSB exposed to radiant heat. The following ignition parameters were used to observe the process of particleboard and OSB ignition: heat flux intensity (from 43 to 50 kW.m-2) and ignition temperature. The time-to-ignition and mass loss of particleboards and OSB with thicknesses of 12, 15 and 18 mm were monitored and compared. The experiments were conducted on a modified device in accordance with ISO 5657: 1997. Results confirmed thermal degradation of samples. Heat flux had a significant effect on mass loss (burning rate) and time-to-ignition. OSB had higher ignition time than particleboards and the thermal degradation of OSB started later, i.e., at a higher temperature than that of particleboards, but OSB also had higher mass loss than particleboards. The samples yielded the same results above 47 kW.m−2. Thermal analysis also confirmed a higher thermal decomposition temperature of OSB (179 °C) compared to particleboards (146 °C). The difference in mass loss in both stages did not exceed 1%.

Oriented strand boards (OSB) and particleboards (PB) are wooden boards, commonly used in building structures or building interiors. The surface of boards may hence become directly exposed to fire or radiant heat. The aim of this paper is to evaluate the behaviour of uncoated particleboards and OSB exposed to radiant heat. The following ignition parameters: heat flux intensity (from 43 to 50 kW.m-2) and ignition temperature were used to observe the process of particleboard and OSB ignition. The time-to-ignition of particleboards and OSB with a thickness of 12, 15, and 18 mm were monitored and compared. The experiments were conducted on a modified device in accordance with ISO 5657:1997. Results confirmed the thermal degradation of samples. Heat flux had a significant effect on time-to-ignition. OSB had a higher ignition time than particleboards and the thermal degradation of OSB started later, i.e., at a higher temperature than that of particleboards, but OSB also had a higher mass loss than particleboards. The samples yielded the same results above 47 kW.m-2 .