There are many terms in the home improvement world that become interchanged with other similar terms when they have actually very different meanings. Here are a few examples.
Cement/concrete: Cement refers only to the powder that hardens when you add water. If you add sand and aggregate to the mixture, though, you get concrete. So strictly speaking, a cement mixer should be called a concrete mixer.
Sash/window: The part of a window that moves is called the sash. The whole shebang – sash, jambs, sill and everything else – is called a window.
Flue/vent: Both of these things stick out of your roof, but a flue exhausts combustion gas from a fireplace, water heater or furnace – anything with a flame – while a vent leads those nasty gases in your plumbing system to the atmosphere.
Wall/partition: Structurally speaking, a wall is always bearing, while a partition is always nonbearing. In most houses, the exterior walls and at least one wall running down the middle of the house are bearing, while all the other walls – er, partitions – are nonbearing. Since these two varieties aren’t always easy to tell apart, it’s prudent to call in an architect or engineer before you go tearing out either one.
Girder/header/beam: In wood-frame construction, a heavy horizontal member is called a girder if it’s below floor level, a header if it’s over a door or window, and a beam if it’s pretty much anywhere else.
Trim/casing: On the outside of a house, the decorative frame around a door or window is called trim, while on the inside, the same thing is called casing. Go figure.
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