20 — CONSTRUCTION MASTER PROHip/Valley and Jack Rafter KeysHip RafterJack Rafters16”CommonSide[Jack]IrregularSide[I/Jack]The Construction Master Pro uses the rise, run, diagonal, pitch ando.c. spacing values to compute regular (45°) and irregular (non-45°)Hip/Valley and Jack rafter lengths (excluding wood thickness, etc.).When calculating regular and irregular Jack rafter lengths, you will seethe letters “JK” (Common pitch side) or “IJ” (irregular pitch side) and thecorresponding Jack number to the left of your calculator display. Thiswill help you keep track of the descending sizes and which side thecorresponding rafter is based on.[Hip/V] — Hip/Valley RafterFinds the regular (45º) or irregular (non-45º) Hip/Valley rafter length.• Regular Hip/Valley Length: After right triangle/rafter valuesare entered or calculated (e.g., pitch, rise, run), pressing[Hip/V] will calculate the length of the regular Hip/Valleyrafter.• Irregular Hip/Valley Length: If an irregular pitch is entered via[Conv] [Hip/V] (see next page), pressing [Hip/V] will calculatethe irregular Hip/Valley rafter length. (An irregular or “non-standard” roof has two different pitches/slopes.)
