Roof Flashing Requirements

Install shingles over the portion of step flashing on the roof.

Roof flashing requirements.

The sketch above illustrates the end profile of roof drip edge flashing and shows its placement on the roof. Flashing against a vertical front wall as well as soil stack vent pipe and chimney. All laps shall be a minimum of 4 inches 102 mm fully sealed in approved flashing cement. The recommended width of step flashings will vary depending on the agency entity being referenced.

The vertical side will be hidden behind the exterior wall covering material. The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. Manufacturers requirements can vary anywhere from 2 inches to 10 inches and you probably won t be able to see the sidewall flashing completely anyway. Flashing against a vertical sidewall shall be by the step flashing method.

The recommended length of step flashing is typically a minimum of 2 inches longer than the exposure of the roofing material. Both codes also contain requirements for roof decks underlayment flashing structural performance and materials and testing criteria. The entire edge of the horizontal flange shall be sealed covering all nail penetrations with approved flashing cement and membrane. Usually you won t see much of drip edge as it s under the roof shingles under the underlayment and behind the roof gutter.

Install house siding over the step flashing ending at least one inch above the roof surface. The requirements of these codes must be followed. This results in a 2 inch minimum head lap. If metal the flashing should be made of galvanized steel at least 0 019 inches thick irc 2015.

The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures. Shall be sheet metal or of the same material as the roof covering. Typically 10 by 8 inch 253 mm x 203 mm flashing is chosen. Check the roof measurements projections flashings slope vents etc check the attic sheathing ventilation insulation.

Lengths of drip vary but typically it s sold in ten foot lengths 120. Install roof felt prior to installing the step and kick out flashing. Step flashing size requirements vary according to manufacturer. Requirements for roof coverings installed in high wind areas i e where the basic wind speed is 110 mph or greater are provided.

Some building codes have specific requirements for underlayment and ice dam protection.