Gypsum walls entrap what percentage of water?

Gypsum walls, commonly used in construction for their fire-resistant properties and ease of installation, can entrap a significant amount of water. Gypsum is a mineral composed largely of calcium sulfate dihydrate, which contains water in its crystalline structure. Approximately 20% of the weight of gypsum can be attributed to water, which is an essential factor in its ability to act as a barrier against flames.

This characteristic also influences the material's performance when exposed to fire; as the gypsum heats up, the water is released as steam, helping to keep the wall structure cooler for longer periods. Understanding this percentage is vital for firefighters and building inspectors, as it impacts how gypsum board behaves in fire scenarios, including how long it can withstand heat before it starts to fail.

Recognizing the amount of water contained in gypsum walls is also critical when assessing the implications of water damage in a building, as absorbed moisture can lead to structural weakening and mold growth if not addressed properly.