Sprinkler heads in ‘dead’, hard to access spaces could be problematic because they are not easy to inspect or could be inadvertently overlooked. BS EN 12845 Sprinkler Rules makes a reference to unventilated concealed spaces in paragraph 14.4 but does not mention the accessibility of the space.
It states the following: ‘In unventilated concealed spaces it may be necessary to install sprinklers with a higher operating temperature, up to 93°C or 100°C. Sprinkler heads in such spaces will operate if the temperature exceeds their normal operating temperature’.