Residential Roofing Replacement


Shingles shall be applied only to solidly sheathed roofs; all delaminated/rotted plywood must be replaced. Shingles shall be applied according to manufacturer's printed instructions and Section R905 and as amended per the 2018 ICC International Residential Code for One-and Two family dwellings.


If the existing roof has two or more layers of any type of roof covering system, a "tear-off" (removal) of the existing covering system needs to be done to provide a weather resistant envelope and ensure that the structural support of the roof is safeguarded.


Slope is determined by rise and run. For example, a 4 inch rise in 12 inch run, equals 4/12 slope or pitch.

Required Inspections

  • Ice and Water Shield
  • Final

Section R905 Requirements for Roof Coverings

  • R905.1 Roof covering application. Roof coverings shall be applied in accordance with the applicable provisions of this section and the manufacturer's installation instructions.
  • R905.2.1 Asphalt shingles. The installation of asphalt shingles shall comply with the provisions of this section.
  • R905.2.1 Sheathing requirements. Asphalt shingles shall be fastened to solidly sheathed decks.
  • R905.2.2 Slope. Asphalt shingles shall only be used on roof slopes of two units vertical in 12 units horizontal (2:12) or greater. For roof slopes from two units vertical in 12 units horizontal (2:12) up to four units vertical in 12 units horizontal (4:12), double underlayment application is required in accordance with Section R905.2.7.
  • R905.2.3 Underlayment. Unless otherwise noted, required underlayment shall conform with ASTM D 226. Type I, or ASTM D 4869, Type I. Self -adhering polymer modified bitumen sheet shall comply with ASTM D 1970.
  • R905.2.4 Asphalt shingle. Asphalt shingles shall have self-seal strips or be interlocking, and comply with ASTM D 225 or D 3462.
  • R905.2.5 Fasteners. Fasteners for asphalt shingles shall be galvanized steel, stainless steel, aluminum or copper roofing nails, minimum 12 gage [0.105 inch (2.67 mm)] shank with a minimum 3/8-inch (9.5 mm) diameter head, ASTM F 1667, of a length to penetrate through the roofing materials and a minimum of ¾ inch (19.1 mm) into the roof sheathing. Where the roof sheathing is less than ¾ inch (19.1 mm) thick, the fasteners shall penetrate through the sheathing. Fasteners shall comply with ASTM F 1667.
  • R905.2.6 Attachment. Asphalt shingles shall have the minimum number of fasteners required by the manufacturer. For normal application, asphalt shingles shall be secured to the roof with not less than four fasteners per strip shingle or two fasteners per individual shingle.
  • Section R905.2.7.1 Ice protection shall be amended to read: All asphalt shingle roofs shall have ice protection. The ice barrier shall consist of at least two layers of underlayment cemented together or of a self-adhering polymer modified bituminous sheet in lieu of normal underlayment and shall extend from the eave's edge to a point at least 24 inches from the inside of the exterior wall line and at all valleys 24 inches from the center line of the valley.
  • R905.2.8.2 Valleys. Shall comply with manufactures installation instructions and Table R905.2.8.2 (Table for Valley living materials).


The following is recommended as good construction practice-but not required:
  • If a homeowner chooses to install a roof on their own, or with the help of family or friends, it is recommended that proper insurance coverage be available.
  • An aluminum drip edge at roof perimeter is recommended


Be advised that a Roofing Contractor is required to have a License from the State of Illinois (with insurance coverage) on file with the Building Department before we issue a permit. To download the Residential Roofing Replacement Requirements please visit: