www.IWSCalc.com
Fill in the areas in RED to calculate membrane area of ice / water / membrane for eaves. If valley SQFT is required, fill in areas in BLUE. Results for each & accumulative total appear in GREEN
"The IWS Calculation Triangle"
Run is calculated by Pythagorean Theorem area of 2 ft. to the interior, considering a 6" exterior to interior wall, in correlation of pitch.
Variables
Roof Pitch: /12
Rise:
Run, calculated:
Rafter:
Calculates area of 2 ft. to the interior, inculding a 6" exterior to interior wall
Run = Eave overhang + 6" exterior wall to the interior of home Eave Length: ** Note: Keep in mind variations in pitch and overhang would be calculated separately if not consistent throughout the roof eaves.