The horizontal run has no pitch.

The PVC pipe goes vertically up from the pump for about four feet and then there is a horizontal run of 14 feet.

Waste pipes should be well supported - every 500mm for horizontal runs of 32mm pipe and every 1.2m for vertical ones.

Other considerations may be added to overall head pressure, including loss from elbows/bends and friction loss from long horizontal runs.

The most coveted houses are those with 7/12 pitch roofs, roofs that rise 7 inches for every 12 feet of horizontal run.

He pointed out, however, that connecting the horizontal runs of the gutter invited the potential for leaks at the seams.

On large or uneven surfaces, the flashing is best let into a horizontal run of pointing and sealed in with mortar.

(This is the angle α opposite the "rise" side of a triangle with a right angle between vertical rise and horizontal run.)

Slope may still be expressed when the horizontal run is not known: the rise can be divided by the hypotenuse (the slope length).

But in practice the usual way to calculate slope is to measure the distance along the slope and the vertical rise, and calculate the horizontal run from that.