The wooden beams on ceilings can have a few different names. If they're structural supports, they're either joists or rafters; joists are horizontal, running across a ceiling to help hold it up, while rafters are sloped to run along the pitch of the roof. But if the ceiling beams you're looking at are decorative instead of structural, they're simply called wooden beams. These may be made of real wood, but often, faux wood beams are used instead, as they're easier to install and more resilient.