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Joists / Joist Hangar

- parallel timbers which carry floorboards. There are sometimes two levels of joists, in which case the upper row are termed bridging joists, the lower are binding joists. A floor where the joists are left exposed is often referred to as an open floor.

A Joist Hanger is a metal box open at one end, capable of being fixed to walls to receive the end of a joist so that the joist end does not have to be built into the wall where it might be prone to rot or reduce fire resistance in the structure. Initially, joists were laid with their longest section horizontal, probably a result of round timbers simply being adzed flat on two opposite side to take floorboards and laths, and then, as sawing techniques improved, probably from the later seventeenth century onwards, it was more usual for them to be laid vertically, on their narrow edge.