(1) Slope of a roof. Pitch is the ratio of vertical rise to horizontal run. (2) To toss at a mark. (3) The key or high or low of an instrument or voice. (4) To fall or plunge headlong. (5) To incline downward. (6) The number of threads or teeth per inch. (7) Resin substance from tar residue. 8. Amount of turns of a spiral per unit length.
Pitch board
Template for building stairs, which is cut in the identical size and shape of the preferred stair stringers to be used to make duplicates.
Pitch control
A method of controlling a wind turbine's speed by varying the orientation, or pitch, of the blades, and thereby altering its aerodynamics and efficiency.
Pitch diameter
Threaded cylindrical object diameter at a midway point between the diameter at the root or base of the threads and the maximum outside diameter of the threaded portion.
Pitch pan or pitch pocket
A container, usually formed of sheet metal, around supporting connections with roof-mounted machinery. Filling the container with pitch, or better yet, plastic roof cement, helps seal out water even when vibration is present.
Pitch pocket (pitch pan)
A flanged piece of flashing material placed around irregularly shaped roof penetrations and filled with grout and a pourable sealer to seal around the penetration in order to seal it from against moisture entry. Pitch pockets are a good source of leaks and should be avoided if possible.
Pitch seam
Wood defect that occurs when a check or shake is filled with pitch.
Pitch vial
The pitch vial was developed to aid in establishing a grade slope, or pitch, to promote drainage. Vial markings indicate level and inches per feet of pitch in 1/8 inch increments.
Pitch wall
Wall whose upper plate slopes to match that of the roof.
