Abstract: High pressure water mist fire extinguishing system will cause water stain damage on the wooden components, in order to understand the water- stain loss, this paper studied the rates of water content, drying rates in shade and rotten state of 10 kinds of wood. Through setting up an experiment platform and conducting simulation experiments, the change of water content in the experimental wood bricks after spraying high pressure water mist was tested under different atmospheric humidity and temperatures, the trend of water content, drying rates in shade and rotten state of the experimental wood bricks after spraying were analyzed. The experimental results showed that the measured values of the water content in the experimental wood bricks after spraying high pressure water mist were within 35%, after drying 2 h，the values dropped to 20%, and the values decreased below the equilibrium water content of Henan province after drying 5 h in shade, the experimental wood bricks didn’t decay after 45-days. Through the introduction of the fire protection design project of Jidu Temple, highpressure water- mist fire extinguishing systems technical advantages in the fire- fighting renovation of ancient buildings are illustrated, which provides reference for the design of fire extinguishing system in ancient buildings.

Key words: water content of wood, high pressure water- mist fire extinguishing system, ancient buildings, water damage, wood decay