Disclosed is a floor assembly for a modular building unit that avoids the need to turn the floor assembly frame over for installation of a floor subsheet, and that likewise provides a modular floor subsheet that may be fitted to the modular building unit without welding, rivets, screws, or other tooling. A floor assembly frame includes side rails that form the exterior, bottom perimeter of the modular building unit, and joists that extent between parallel side rails of the floor assembly frame. The joists are configured at their base on one side with a slot configured to receive one end of a section of a floor subsheet. An opposite end of the floor subsheet is then positioned overtop the joist element that forms the top portion of the slot on an adjacent joist, which opposite end may then be held in place with a pin, clip, or other fastener requiring minimal effort to install. Such assembly allows all components of the floor to be installed from above, thus avoiding the need to invert the frame of the floor assembly during installation. Likewise, the modular nature of the assembly allows installation to be carried out by fewer personnel than required in traditional installations.

A ceiling system configured such that when a runner of a first panel assembly and a runner of a second panel assembly are each slidably disposed within a channel of a rail and the rail is attached to the support member, the first panel assembly and the second panel assembly are independently suspended by respective wires from the rail. Sliding the runner of the first panel assembly towards the runner of the second panel assembly translates the respective panels of the panel assemblies towards each other, thereby positioning an edge of the panel of the first panel assembly adjacent an edge of the panel of the second panel assembly for attachment, such that the second planar surface of the panel of the first planar assembly and the second planar surface of the panel of the second planar assembly at least partially define an interior surface of the ceiling.

A ceiling system comprising a ceiling tile comprising a backer panel and a plurality of ceiling components assembled to the backer panel is disclosed. The ceiling components include connectors that pass through openings in the backer panel and protrude from a top surface of the backer panel and are configured to mount the ceiling tile to a ceiling hanger system.