Kick-out flashing — IRC R905.2.8.3 wall-to-roof termination, concealed wall damage when omitted, SMACNA detail

Where a sloped roof meets a vertical wall that continues downward past the eave — a configuration common on homes with attached garages, two-story walls over single-story rooflines, dormers, and second-story bumpouts — water running down the step flashing at the wall must be redirected at the bottom of the step or it follows the wall surface down behind the siding or stucco. Kick-out flashing (also called diverter flashing) is the small angled metal piece that performs that redirection, kicking the wall-shed water out into the gutter trough or onto the roof slope below. IRC Section R905.2.8.3 specifies that base flashing against a vertical sidewall be continuous or step flashing, not less than 4 inches in height and 4 inches in width, and that it direct water away from the vertical sidewall onto the roof or into the gutter. At the lower termination of the step flashing run, the code requires the flashing to be turned out in a manner that performs that diversion — the kick-out detail. SMACNA's Architectural Sheet Metal Manual (7th Edition) contains the standardized kick-out flashing detail and dimensions. When kick-out flashing is omitted — a documented common omission, particularly visible on stucco-clad and fiber-cement-clad walls — water sheets off the roof edge directly onto the wall surface immediately below the intersection, where it gradually penetrates the siding lap and reaches the sheathing behind. The resulting damage is concealed: by the time stains, blisters, or interior water spots appear, the sheathing and structural framing at the wall-roof corner may already be compromised. James Hardie's HardiePlank install specification explicitly flags missing kick-out flashing as a primary cause of warranty-disqualifying water damage, and ASHI and InterNACHI home inspector practice standards both call out kick-out flashing inspection as a routine line item. Kick-out flashing is one of the simpler line items to verify post-install: from the ground, a small metal piece should be visible at the bottom of any wall-to-roof intersection where the wall continues past the eave, directing flow into the gutter or onto the roof below. Absence shows as a clean wall-to-roof junction with no metal kick — typically accompanied, over years, by a staining or blistering pattern on the wall directly below the intersection. The flashing piece itself is inexpensive; the wall-system damage from its omission can run into thousands of dollars by the time it is discovered. Whether a specific home has properly installed kick-out flashing is a qualified inspector or roofer call from up-close; the ground-level visual is the homeowner-accessible signal. [Source: IRC Section R905.2.8.3 sidewall flashing; SMACNA Architectural Sheet Metal Manual 7th Edition (2012); NRCA Roofing Manual flashing chapter; James Hardie HardiePlank install specification — kick-out flashing requirement; ASHI Standard of Practice — flashing inspection requirement; Building America Solution Center roof-wall flashing guidance]