- 1. At top of all exterior window and door openings in such a manner as to be leakproof, except that self-flashing windows having a continuous lap of not less than 11/8 inches (28 mm) over the sheathing material around the perimeter of the opening, including corners, do not require additional flashing; jamb flashing may also be omitted when specifically approved by the building official.
- 2. At the intersection of chimneys or other masonry construction with frame or stucco walls, with projecting lips on both sides under stucco copings.
- 3. Under and at the ends of masonry, wood or metal copings and sills.
- 4. Continuously above all projecting wood trim.
- 5. Where exterior porches, decks or stairs attach to a wall or floor assembly of wood-frame construction.
- 6. At wall and roof intersections.
- 7. At built-in gutters.
“At wall and roof intersections“ (mentioned in #6 above)-- that is all they say about where kickout diverter flashings are needed. Surprisingly, they don’t actually name the specific flashing that will resolve the water entry challenge. This is unusual for the IRC.
The IRC is a big book of written guidelines that also has many wonderful spec drawings to help clarify where needed so as to prevent confusion. For some reason, the code authors did not find it necessary to share any detail or spec drawings for item #6. They did share lots of other illustrations to clarify the new brick flashing guidelines that include the now required weep holes in brickwork. Unfortunately, the lack of having a picture detail of kickout flashings allows a little wiggle room of ignorance for builders and their roof and exterior covering sub-contractors. In the Roof Assemblies section of the IRC, under Weather Protection, it states:
- R903.1 General. Roof decks shall be covered with approved roof coverings secured to the building or structure in accordance with the provisions of this chapter. Roof assemblies shall be designed and installed in accordance with this code and the approved manufacturer’s installation instructions such that the roof assembly shall serve to protect the building or structure.
This means that the manufacturers of the exterior claddings and roofing materials get to establish the finer details of the needed flashing installations. And if they are mandated by the manufacturer, then they are required by the International Residential Code.
PLEASE NOTE: Check with your local Authority Having Jurisdiction (AHJ) to determine what is required in your area. The local officials are not supposed to water down the codes and manufacturer’s specs, but they are allowed to require even more stringent standards. Take for instance the cities of Sandy & Draper, Utah. These two neighboring building departments got together and came up with strict flashing details to prevent any further wall failures due to water entry relating to poor flashing and drainage planes. This is a case where the AHJ’s made local requirements that are much stricter than those listed in the International Residential Code.... Kudos to Sandy & Draper, Utah.
PLEASE NOTE - TAKE TWO: The only shame is that the cities of Sandy & Draper were not 10 years quicker. That would have saved a lot of grief and expense to those homeowners still suffering great losses on predominantly stucco homes built between 1987 and 1999 when the flashing installations were greatly overlooked. They are now getting better, but mis-installations are still occurring.
manner as to prevent entry of water into the wall cavity or penetration of water to the building structural framing components. The flashing shall extend to the surface of the exterior wall finish and shall be installed to prevent water from reentering the exterior wall envelope. Approved corrosion-resistant flashings shall be installed at all of the following locations:
