What is the difference between true and level in building trades?

Answer 1

The terms "true" and "level" are very important when building or repairing any structure, whether it be a wall, a roof, a ceiling, or anything in between.

Let us break down what we know of these two terms:

"Level" - When each part of a particular structure (floor, wall, roof, etc.) is the same height, width, or depth as any other independent part of the same structure. Picture placing down tile, if there are lots of dips and hills in your subfloor, your tile will not lay correctly making the grout or even the tile crack, this is unlevel.

"True" - When each part of a particular structure (see above) are not the same height, but share a common different slope and/or when two different parts (a wall and a floor) are not level but still meet each other all the way around - i.e: no gaps between the floor and wall. Picture placing tile again, only this time on a floor which has a grade which is 1 inch higher on one side of the room than the other. This slope may be intended, so the subfloor is not "level" but is "true" in the sense that one side of the subfloor is substantially lower than the other, but is consistent across the width of the entire floor, creating an intended slope.

There are many other examples of "level" and true" in the building world, but this summation should be enough to answer the stated question.