Roofing Residential & Commercial
RESIDENTIAL ROOFING INFORMATION – ASPHALT SHINGLES
The following requirements are for asphalt shingles used on residential roofs. This is not intended as a complete list of requirements. Please refer to Chapter 9 of the 2020 MN Residential Code. The shingle manufacturer’s installation instructions should always be followed.
- Asphalt shingles shall not be installed on roofs with less than a 2:12 slope. See item number 5 for additional underlayment requirements for roofs under 4:12 pitch.
- New roof coverings shall not be installed without first removing the existing roof covering where any of the following conditions exist:
- Existing roof is water soaked or deteriorated.
- Existing roof covering is slate, clay, cement, or asbestos-cement tile.
- Existing roof has 2 or more application of any type of roof covering.
- Damaged sheathing shall be replaced with new sheathing having a grade stamp and rated for exterior use.
- Ice protection shall be installed on all roofs, including porches and attached garages. Ice protection is not required on unheated detached accessory structures. Protection shall be from the eave to a point twenty-four (24) inches inside the exterior wall line. The ice barrier shall consist of two layers of felt cemented together or a self-adhering polymer modified bitumen sheet. Photos of the ice barrier are required on site at the scheduled final inspection.
- In addition to ice protection, underlayment is required under all asphalt shingles and shall consist of a minimum of one layer of #15 felt or other approved products. Underlayment for slopes under 4:12 shall consist of two layers of felt, lapped 19 inches horizontally.
- All metal flashing shall be made from corrosion-resistant metal. Flashing is required at sidewalls, valleys, around pipes, stacks and chimneys. Apply flashing in accordance with manufacturer’s installation instructions. Ice protection material may be substituted for metal flashing in closed valleys (when shingles are woven through the valley).
- If both roof and siding are done together, kick-out flashing shall be installed where the lower portion of a sloped roof stops within the same plane of an intersecting wall.
- A cricket or saddle shall be installed on the ridge side of any chimney or penetration more than 30 inches wide and shall be corrosion-resistant sheet metal or of the same material as the roof covering.
- Roof vents shall be replaced or added to provide attic ventilation. The area of the attic determines the required net free area. For a roof with soffit (eave) vents, divide the area of the attic by 300 to find the net free area of venting required. One half of this venting should be on the roof (near the ridge) and the other half in the soffit.
- Approved roofing nails shall be used. Nails shall be of sufficient length for secure attachment.
Please note: There are separate permit fees for Roof Replacement and Roof Repair. A roofing repair permit is valid for 500 sq. ft. or less; otherwise a roof replacement permit is required.
For more information and visual examples for residential roofs, see Related Documents.
COMMERCIAL FLAT ROOFING CHECKLIST
- Full written scope of the project submitted to owner.
- Shop drawing/section view of new installation system, including structural components of the existing roof.
- A listing (name) of each specific manufacturer’s product being installed.
- The flame spread documentation for any foam products being installed.
- The thickness of all products being installed.
- The fire tested assembly number designation. (U.L. Factory Mutual, ICC)
- Any documentation from a Minnesota registered structural engineer.
- Copy of the manufacturer’s installation instructions.
Plan Review fees will not be charged for commercial roofing projects
PLEASE ANSWER THE FOLLOWING QUESTIONS:
- Are all the existing roofing materials being removed to the structural deck?
- How many sq. feet is the existing roof? ______ How many sq. feet are being replaced? ______
- What type of roofing system currently exists?
Built-up Membrane Other
- What type of roofing system is proposed?
Built-up Membrane Other
- Will the new roofing materials reduce or increase the current dead load?
Increase Reduce No Change
- If loading is to be increased, has a structural engineer been hired to review all allowable loads?
*Yes No *If yes, attach an Engineer’s report
- Are any new drainage devices being added or altered as part of the re-roof?
- Per Minnesota Building Code Table 1505.1 what class designation is the new roof system?
A B C Non-classified
- What overall R-value will the new roof produce? ________________
- Per Minnesota Building Code Section 2603.4, 2603.4.1, and 2603.4.1.5, will a thermal barrier be required as part of the re-roofing project?
- Will any electrical, plumbing, gas, or mechanical items on the existing roof need to be disconnected and reconnected as part of the re-roof?
- Are any electrical, plumbing, gas, or mechanical items being replaced along with the re-roof?