Rebar host elements keep track of the "exposed faces," those that are not completely concealed by another rebar host. Faces may be concealed by joins; for instance, the top face of a beam that supports a slab is concealed. Faces can also be concealed by adjacency; for instance, the bottom face of a column that is supported by a foundation. Each exposed face of a rebar host must have a valid CoverType associated with it.

Rebar hosts also have cover parameters, providing a limited interface to the GetCoverType and SetCoverType methods. Each parameter simply gets or sets the cover setting associated with one or more particular faces of the host.

• CLEAR_COVER_EXTERIOR (walls only)
• CLEAR_COVER_INTERIOR (walls only)
• CLEAR_COVER_OTHER (all hosts except in-place families and stairs)
• CLEAR_COVER (in-place families and stairs)
• CLEAR_COVER_TOP (all hosts except walls, in-place families, and stairs)
• CLEAR_COVER_BOTTOM (all hosts except walls, in-place families, and stairs)