I am involved in a project for a new high-rise office building where a lobby (two-story high) on Level 1 is proposed. The rest of Level 1 is used as a parking garage. Level 2 is office area and part of Level 2 is interconnected to the main lobby on Level 1. The contractor shows a dry system to for the entire Level 1 including the heated spaces within or adjacent to the main lobby on Level 1 (i.e. building manager office, area under grand stair to Level 2, elevator lobby etc.). The wet pipe system is provided throughout Level 2, including the ceiling of the main lobby.
I have pointed out that this configuration is not a good engineering practice and asked the contractor to change the dry pipe system in the lobby areas and adjacent heated rooms on Level 1 to be a wet-pipe system. I have also called out the annex language in Section A.7.2 which indicates a dry system can only be installed if the protected space is not heated. But I received push back from the contractor who claims the design does not violate the adopted NFPA 13 (2013 edition).
Is there a section in NFPA 13 clearly states that it is not allowed to have multiple types of sprinkler systems (i.e. dry and wet) within the same enclosure? It just feels wrong to have different types of sprinkler systems within the same enclosure.
Thank you in advance.