In timber-framed buildings, a bressummer is a heavy beam supporting the upper floor(s) of a jettied building, i.e. one where the upper floors overhang the ground floor.
Such beams are often carved and decorated (to demonstrate the wealth of the original owner.)
A bressummer can also be the massive timber beam above a fireplace, which supports the brickwork of the chimney, as found in many period properties.
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