How the EDGE Calculates Gables & Rakes

Calculating Gable/Rake in The EDGE

For The EDGE to calculate the pitch of a Hip/Valley of a roof, it has to calculate it based on a specific point of view, every time.
The EDGE uses the PLAN VIEW to calculate measurements and to apply a specific formula to its calculation. That formula is the tried and true “Pythagorean Theorem” using the following examples.

First, we’ll start with the Gable end of a roof.

Let’s say the Gable end of a roof is 24′ wide and 6′ high at the ridge line. This means that half the width would be 12′ with the ridge still 6′ high. Or, two back to back right triangles. Using the dimensions above you would have a roof with a 6/12 pitch.

Using the Pythagorean Theorem (a2 + b2 = c2) where a = 6′ and b = 12′, The EDGE then calculates the distance of the Hypotenuse (c2).
A2 = 6 * 6 = 36
B2 = 12 * 12 = 144
36 + 144 = 180 = c2
C = 13.416
So, when you measure a Gable End, in “Plan View”, if the Flat (Base of Gable) is 12′, The EDGE Gable Length will show 13.416′.

Now, that being said, if we take 13.416 and divide it by 12 ( 13.416 / 12 ), this will give us our “multiplication factor” for our pitch.
13.416 / 12 = 1.118

This is the factor that The EDGE uses to measure, IN PLAN VIEW, for a 6/12 Pitch.