Definitions for "Collar beam"
Keywords:  rafter, stiffen, tie, carpentry, beam
a horizontal timber which ties rafters together at a height above the wall plate, ie above the level of a tie beam.
In carpentry, a tie that keeps the roof from spreading. Inside the attic, it connects similar rafters on opposite sides of roof.
A horizontal beam nailed to each of two opposing rafters to provide support to the rafters.