In carpentry, the term "level" refers to one of two definitions: a line that is parallel to the horizontal plane, or a tool used ensure that a line is level. There are several types of leveling tools, including line levels, which can be hung from a horizontal cord; laser levels, which project a beam across a flat surface; and chalk lines, which use a string coated with chalk to mark a straight line between two points.
A plumb bob is a pointed metal bulb that hangs from a string. The plumb bob is used to find a point exactly below another point.
A plumb bob can be used to ensure that a wall or other vertical surface is totally straight.
A bearing wall is a wall that carries weight in addition to its own weight. This weight comes from structural elements above the bearing wall like a second story, a roof or the ceiling.
Bearing walls are always functional rather than cosmetic, and cannot be removed without damaging the safety of the building.
Pitch is an expression of angle, slope, or incline. It is most commonly used in roof and stair building.
A beam is an architectural element that is used to support loads over windows and doors. Beams run parallel to the floor and are usually supported at the ends by a column or bearing wall.
A joist is a horizontal structural element, similar to a beam. Like bearing walls, joists hold weight from above.
Joists run parallel to the ground.
The term "plumb" refers to an exact vertical line that is perpendicular to the floor. It is most commonly used when framing walls: walls are in the correct position when they are plumb.
An "A" brace is a wooden brace that is used to keep walls in place as other walls are built. They are temporary, and are named for their distinctive "A" shape.
The peak is the highest point of a roof. It is also the point where the roof rafters meet.
A nonbearing wall is a wall that does not bear weight from elements above it. These walls are usually cosmetic, and can be removed without damaging a building's structural integrity.
A rafter is a structural element that makes up and supports the roof. There are four types of rafters: hip rafters, jack rafters, cripple rafters and valley rafters.
They differ in their placement in the roof, and in their supporting function.