Roofing Requirements

CITY OF LITTLETON BUILDING DIVISION

Policy #24-001

3/27/2024

 ROOF COVERING INSTALLATION AND INSPECTION REQUIREMENTS

PURPOSE

To ensure the proper installation and inspection of roofing coverings, clarification of applicable codes, and consistency in application and inspection procedures.

POLICY Section 1 – Asphalt shingle, metal, or clay/concrete tile replacement

Installation and inspection of asphalt, metal or clay/concrete shingle or tile roof coverings shall comply with all adopted City of Littleton codes and amendments and the following:

1. Permits are required to be obtained prior to commencement of work and displayed in a location visible from the street and shall provide a complete description of work, including replacement or overlay of roof sheathing. All roof coverings and systems shall be installed in compliance with applicable codes and manufacturer’s installation guidelines. In the case of a conflict between manufacturer’s installation guidelines and adopted codes and amendments, the most restrictive requirements shall apply. Work initiated prior to obtaining a permit or without a valid City of Littleton contractor’s license may result in the issuance of a Stop Work order and/or municipal summons. Inspections will not be completed unless a valid permit is on site and in a visible, accessible location. The City of Littleton requires full tear off to deck. No overlays will be accepted.

    

2. Clay and concrete tiles may be reused provided the manufacturer allows it, and the warranty will still be valid.

    

3. Roof decks with spaced or board sheathing that are to receive asphalt shingles or clay/concrete tiles and that have any gap exceeding 1/2-inch shall be required to be overlaid, or replaced with panel sheathing such as plywood or OSB that is a minimum of 3/8-inch in thickness. Amendment of existing permits is required if the need for installation of sheathing is discovered after permit issuance and sheathing installation was not previously indicated on the permit. If a permit was not required for the roof covering, but the area of sheathing needing installed or replaced is large enough to require a permit, a roof permit must be obtained. Sheathing panels shall be fastened with nails spaced at a maximum of 6 inches on center at edges and 12 inches on center in rows not further than 24 inches apart and vertical panel edges shall break on framing members. When sheathing is overlaid or replaced an inspection of sheathing fastening by Building Division staff is required prior to installation of roof underlayment or coverings.

    

4. Ice and water barrier underlayment complying with ASTM D1970 and extending a minimum of two (2) feet inside the exterior wall line is required at eaves of all conditioned structures. In valleys, one of the following materials is required: Closed Valleys - Ice and water barrier underlayment a minimum of 36 inches wide; Open Valleys - one(1) layer of 24-inch wide galvanized metal; or two(2) layers of mineral-surfaced rolled roofing, one(1) 18 inches wide and one(1) 36 inches wide.

    

5. Galvanized drip edge flashing is required at all roof edges.

    

6.  Asphalt shingles complying with ASTM D3462, D7158 and D3161 are permissible for use as established in the  2021 IRC Section R905.2.4. All asphalt shingles are required to be nailed with a minimum of six (6) nails per shingle. Asphalt shingles may not be installed on roofs below 2/12 pitch. Double underlayment or ice and water barrier underlayment is required if asphalt shingles are installed on a roof pitch between 2/12 and 4/12.

    

7. Roof ventilation shall meet or exceed existing roof venting conditions. Roof venting changes must comply with IBC Section 1203 or IRC Section R806.2: 1 square foot of ventilation opening is required for every 150 square feet of attic space. If ventilation is provided at an approximate rate of 50/50 between upper roof and lower roof/soffits, 1 square foot of ventilation opening is required for every 300 square feet of attic space.

    

8. A final roof inspection is required to complete and close permits. An OSHA compliant ladder setup, extending 3 feet above the roof eave, shall be provided and secured at the time of inspection for all roof inspections, and permission to enter the yard is required if the inspector must pass through a fence or enter the rear yard of the property to access the ladder. Inspectors will not go through fences or enter rear yards without permission or when pets are present.

POLICY Section 2 – Replacement and Overlays of all other roof coverings

Installation and inspection of all other roof coverings shall comply with the following:

1. Permits are required to be obtained prior to commencement of work and displayed in a location visible from the street and shall provide a complete description of work, including replacement or overlay of roof sheathing. Overlays of membrane type roofing will be permitted. Liquid applied overlays require a product submittal supplied to the building division for approval prior to permit issuance, and work commencement. Mineral-surfaced roll roofing is not permitted in the City of Littleton. Modified bitumen roofing is acceptable. Work initiated prior to obtaining a permit or without a valid City of Littleton contractor’s license may result in the issuance of a Stop Work order and/or municipal summons. Inspections will not be completed unless a valid permit is on site and in a visible, accessible location.

    

2. Roof decks with spaced or board sheathing that have any gap exceeding 1/2-inch shall be required to be overlaid, or replaced with panel sheathing such as plywood or OSB that is a minimum of 3/8-inch in thickness. Sheathing shall be nailed with nails spaced at a maximum of 6 inches on center at edges and 12 inches on center in rows not further than 24 inches apart.  When sheathing is overlaid or replaced an inspection of sheathing fastening by Building Division staff is required prior to installation of roof underlayment and coverings.

    

3. All roof coverings and systems shall be installed in compliance with applicable codes and manufacturer’s installation guidelines. Installation guidelines shall be submitted at time of permit application and be available on site at the time of all inspections. In the case of a conflict between manufacturer’s installation guidelines and adopted codes and amendments, the most restrictive requirements shall apply.   

    

4. In order to receive approval of a final inspection on commercial membrane or similar type roofing, a final roof inspection must be conducted by the Building Division, and a warranty certificate must be provided and attached to the building permit.  A 3^rd party engineer’s observation letter will not be accepted in lieu of a final inspection without prior authorization by the Chief Building Official.

POLICY – Section 3 Definition of roof repair, and partial roof replacement

1. Roof repair, residential or commercial, shall be deemed to be the removal and/or replacement of equal to or less than one square (100 square feet) aggregate of existing roof covering. Removal and/or replacement greater than one square (100 square feet) shall be deemed to be roof replacement for the purposes of determining applicability of adopted code(s). If a permit was not required for the roof covering, but an area of sheathing needing installed or replaced is large enough to require a permit, a roof permit must be obtained.

    

2. Roofing installation that exceeds the definition of a repair as outlined above on roofs covered by Section 1, shall require full roof replacement.  Partial new roof installation shall be allowed where a structure has been expanded creating a new roof plane, or an extension of an existing roof plane, without the need to replace the entire roof.  Partial roof replacements on roofs covered by Section 2 will be allowed provided a durable splice can be achieved that meets all provisions within the adopted codes and the City Code amendments.

POLICY – Section 4 Provisions for removal and replacement of photovoltaic systems

1. If City of Littleton records, or any other evidence deemed appropriate by the building official, indicate the structure is equipped with a photovoltaic (solar) assembly, the issuance of a roof permit will be delayed until such time as a solar contractor, licensed by the city, has obtained a permit to remove and replace the system. Removal of the system by the roofing contractor, or work initiated prior to obtaining a permit or without a valid City of Littleton contractor’s license may result in the issuance of a Stop Work order and/or municipal summons.

3^rd Revision 4/5/2024

2^nd Revision 3/22/2024

Enacted       5/20/2020

1^st Revision 7/16/2020