This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
It is often necessary or desirable to have beams showing in the ceiling of certain rooms, and these beams may be either true or false, that is, they may be either an ornamental covering for beams which really exist, or they may be entirely ornamental, enclosing nothing which forms part of the real construction of the building.
Fig. 368 shows how a steel beam may be covered and ornamented so as to give a finished appearance in wood in the ceiling. A A are the floor joists, and B is the steel beam. C is the line of the finished floor above, and D is the line of the finished ceiling. E is the finish of the ceiling beam, and F is a little molding to cover the joint between the plaster and the wood.
In case the beams are false, they are constructed in the same way except that the shell is filled in with blocking to take the place of the real beam shown in Fig. 368.