Roof Flashing Requirements

All laps shall be a minimum of 4 inches 102 mm fully sealed in approved flashing cement.

Roof flashing requirements.

The recommended width of step flashings will vary depending on the agency entity being referenced. Install roof felt prior to installing the step and kick out flashing. Both codes also contain requirements for roof decks underlayment flashing structural performance and materials and testing criteria. 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.

The entire edge of the horizontal flange shall be sealed covering all nail penetrations with approved flashing cement and membrane. Some building codes have specific requirements for underlayment and ice dam protection. Shall be sheet metal or of the same material as the roof covering. Flashing against a vertical front wall as well as soil stack vent pipe and chimney.

If metal the flashing should be made of galvanized steel at least 0 019 inches thick irc 2015. 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. Further your step flashing pieces need to be 10 inches 254 mm long and at least 2 inches 50 mm wider than the exposure of the shingle you re using.

Lengths of drip vary but typically it s sold in ten foot lengths 120. For example 3 tab shingles usually have a 5 5 8 inch 143 mm exposure. The vertical side will be hidden behind the exterior wall covering material. Install shingles over the portion of step flashing on the roof.

Requirements for roof coverings installed in high wind areas i e where the basic wind speed is 110 mph or greater are provided. Flashing against a vertical sidewall shall be by the step flashing method. 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. 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.

Step flashing size requirements vary according to manufacturer. The requirements of these codes must be followed. The recommended length of step flashing is typically a minimum of 2 inches longer than the exposure of the roofing material. Flashing shall start at the lower portion of roof to ensure water shedding capabilities of all metal laps.

Install house siding over the step flashing ending at least one inch above the roof surface.