I am curious to know how other facilities manage this situation. Having been a FPE for several years in my career, I grew up learning that if there is one “sacred rule” regarding hot work it is that Hot Work is NEVER EVER done when the sprinkler system is out of service. It was one of those rules you did not even ask for a “variance” as you would be looked upon in a bad way. We can also point to OSHA’s minimum requirements for Hot Work in 1910.252(a) where it is stated: (emphasis by me)