Roofing - Commercial Flat Roof

      This handout is a compilation of some of the standard requirements based on the State Building Code and City Ordinance for projects of this type.  This information packet does not contain all the specific codes for construction and should only be used as a guide. The permittee is responsible for meeting all code requirements applicable to each project.

Note: If the property is a Heritage Preservation Site prior approval from City Planner and/or HPC is required before issuance of permit. 

Submittals:

• Building Permit Application
• Plan view
  • Dimensions
  • Drainage plan
  • Insulation
  • Roof top structures
  • Perimeter and corner dimensions for enhanced fastening requirements
• Insulation/coverboard attachment requirements
• Manufacturer specifications of product being installed plus installation instructions
• Indicate new or reused metal components
• Fire Classification of roof
• Engineering Report (if roof load is increased)

Typical Inspections:

Contractor must be onsite to provide access for inspections

• Insulation with Fastener Pattern
• Final

Typical Requirements for Commercial Flat Roofs:

• Roof decks and roof coverings shall be designed for wind loads in accordance with MN 1303.2200
• Flashing shall be installed in such a manner as to prevent moisture from entering the wall and roof through the joints in the copings, through moisture-permeable materials and at intersections with parapet walls and other penetrations through the roof plane. MN 1503.2
• Insulation requirements for roof replacement must meet 2024 MN Commercial Energy Code*. See Table 5.5-6. 

Table 5.5-6 Building Envelope Requirements for Climate Zone

*Exception: Where insulation is provided above the roof deck, and the required R-value cannot be provided because of thickness limitations, the maximum insulation compatible with the available space shall be installed as approved by the building official.