What makes wood susceptible to fire, mold, termites, and warping?

In the context of building construction, wood is a versatile material that possesses inherent characteristics making it susceptible to fire, biological degradation, and dimensional instability.

Susceptibility Factors

• Fire: Wood is a combustible material that ignites when exposed to sufficiently high temperatures—typically requiring about 250 °C (480 °F) for ignition by a spark or flame, or approximately 500 °C (930 °F) for spontaneous ignition.1
• Mold and Decay: Wood is a biological product that can be attacked by fungi and bacteria. Decay occurs primarily when environmental conditions—specifically moisture, air, and temperature—are suitable for fungal growth. A moisture content above 20 percent significantly increases the risk of decay.2
• Termites: These insects are attracted to wood as a food source. Subterranean termites often enter structures from the soil, while dry-wood termites nest directly within the wood they consume.3
• Warping: Wood is hygroscopic, meaning it absorbs and releases moisture from the environment. Fluctuations in moisture content below the fibre saturation point cause the wood to shrink or swell. Because these dimensional changes are often uneven, they lead to warping, cracking, and other forms of distortion.4

Understanding these properties is essential for proper material selection and the application of protective treatments, such as fire retardants or chemical preservatives, to ensure the longevity of wooden structures.56