Re-Roof Policy

Reroofing

The City of Lincoln & Lancaster County has adopted and enforces all sections of the 2018 international Residential Code (IRC) and the 2018 International Building Code (IBC). Reroofing must comply with Chapter 9 of the IRC, Chapter 15 of the IBC, the respective adopted amendments and the manufacturer’s installation instructions.*

A Building Permit is required if:

1. There is rot damage to the roof sheathing and/or rafters.
2. 7/16” plywood or OSB sheathing is used to cover the existing roof sheathing. IF the space between the existing boards does not exceed ¼”, new roof sheathing is not required.

Shingling a roof that has solid sheathing does not require a Building Permit, but all code requirements and the manufacturer recommendations and installation instructions apply. If the existing roof has two (2) or more layers of any type of roof covering, all of the layers must be removed.

Ice Barrier is required for all spaces. (R905.1.2) The self-adhering sheet shall extend from lowest edges of all roof surfaces to a point not less than 24” inside the exterior wall line of the building.

Flashing:

• Valley flashing must be a minimum of 24” wide. Multiple sections require a minimum end lap of 4”.
• Step flashing (4”x 4”) is required on a sloped roof where rows of shingles abut a wall.
• Drip edge flashing is required on all eaves and gables.
• Flashing for a wall that is perpendicular to the roof slope shall be per the shingle manufacturer’s installation instructions.
• Chimney flashing (also referred to as a cricket or saddle) is required on chimneys that are 30” or wider.
• Flashing that is damaged, rusted, and flashing that had been installed incorrectly shall be replaced.

Flat Roofs: Mineral-rolled roofing is permitted on slopes of 1” in 12” or greater. A one piece membrane or a liquid applied roof covering is required for sloped roofs less than 1” in 12”. The minimum slope for a roof is ¼” in 12” to allow for drainage.

Roof venting, upper ventilation only: When the attic ventilation is 3 ft. or less from the ridge, the minimum ventilation area shall be 1 square ft. of ventilation for every 150 sq. ft. of attic area. Upper and lower ventilation (eave): The minimum upper ventilation shall be 1 sq.ft. of net free ventilation for every 300 sq. ft. of attic area and 1 sq ft. of lower (eave) ventilation for every 300 sq. ft. of attic area.

*Where there is a conflict, the most restrictive shall govern

12/10/2021