2012 International Residential Code R703.8 Flashing
Approved corrosion-resistant flashing shall be applied shingle-fashion in a manner to prevent entry of water into wall cavity or penetration of water into the building structural framing components. Self-adheared membranes used as flashing shall comply with AAMA 711. The flashing shall extend to the exterior wall finish. Approved corrosion-resistant flashings shall be installed at all of the following locations:
1. Exterior window and door openings. Flasing at exterior window and door openings shall extend to the surface of the exterior wall finish or to the water-resistive barrier for subsequent drainage. Flashing at exterior window and door openings shall be installed in accordance with one or more of the following:
1.1. The fenestration manufacturer's installation and flashing instructions, or for applications not addressed in the fenestration manufacturer's instructions, in accordance with the flashing manufacturer's instructions. Where flashing instructions or details are not provided, pan flashing shall be installed at the sill of exterior windows and door openings. Pan flashing shall be sealed or sloped in such a manner as to direct water to the surface of the exterior wall finish or to the water-resistive barrier for subsequent drainage. Openings using pan flashing shall also incorperate flashing or protection at the head and sides.
1.2. In accordance with the flashing design or method of a registered design professional.
1.3. In accordance with other approved methods.
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 assymbly of wood-frame construction.
6. At wall and roof intersections.
7. At built in gutters.