Adopted building code
The 2021 International Residential Code, as adopted by the State in the Pennsylvania Uniform Construction Code (UCC). 34 Pa. Code 403.21(a)(7) adopts "The 'International Residential Code of 2021,' except that:" followed by the State's list of exclusions and modifications, effective January 1, 2026 (55 Pa.B. 7701). None of the State's changes touches Chapter 9, Roof Assemblies, or Section R803, Roof Sheathing, so those apply as the International Code Council publishes them. Work on existing buildings is also pointed to the State's existing-building code: "The repair, alteration, change of occupancy, addition and relocation of existing buildings must comply with Chapter 34 of the 'International Building Code of 2021' or with the 'International Existing Building Code of 2021'" (34 Pa. Code 403.21(f)). The UCC is the minimum everywhere in the state: "no municipality may propose or enact any ordinance which is less than the minimum requirement of the Uniform Construction Code" (Pennsylvania Construction Code Act, Act 45 of 1999, section 503(b)). The Act also lists work it "shall not apply to", including "Alterations to residential buildings which do not make structural changes or changes to means of egress" or to "Repairs to residential buildings," in each case "except as might be required by ordinances" kept in force under section 303(b)(1) or adopted under section 503 (Act 45 section 104(b)(5) and (6); 34 Pa. Code 403.1(b)(8) and (9)). The Act defines a repair as "The reconstruction or renewal of any part of an existing building for the purpose of its maintenance." So whether the code's roofing rules reach a given house reroof depends on the municipality's own ordinances. Everything above is Pennsylvania state law, the same in every municipality. Locally, Moosic Borough elects to administer and enforce the Pennsylvania Construction Code Act and adopts the Uniform Construction Code "as the municipal building code of the Borough of Moosic" (Code, Chapter 121, Sections 121-1 and 121-2), and the Borough's Zoning Office page, which carries its building permit application, lists under "Third Party Inspection Agencies" NorthEast Inspection Consultants (N.E.I.C.), of 209 Main Street, Childs; the building permit application is that firm's Building Subcode form. Permits are taken at the Moosic Borough Building, 715 Main Street. Chapter 121 adopts the Uniform Construction Code "as amended from time to time," and neither the Borough's code nor its pages name an edition. Chapter 121 changes nothing in the code's roofing provisions.
Permit process
No Moosic Borough text read for this record says whether a residential reroof needs a building permit. The Zoning Office page lists a "Building Permit" with fees that "Will vary" and names no roof work as needing or not needing a permit. The building permit application lists "ROOFING" among boxes under "TYPE OF WORK," beside new building, addition, alteration, siding, fence and pool; it is a general building permit form, not a roofing form, and the Borough publishes no building fee schedule. Chapter 121 adds no permit clause of its own and names no roof work; Section 121-5A keeps in force building code ordinances adopted on or before July 1, 1999 "which equal or exceed the requirements of the code," and this record has not found or read any such ordinance. The zoning chapter, Section 300-48, says "No person shall erect, alter or convert any structure or building, or part thereof, nor alter the use of any land, subsequent to the adoption of this chapter, until a zoning permit has been issued by the Zoning Officer"; that is a zoning permit, it names no roof work, and this record does not decide whether it reaches a reroof. Under state law, Act 45 section 104(b)(5) and (6) list "Alterations to residential buildings which do not make structural changes or changes to means of egress" and "Repairs to residential buildings" among work the Act does not apply to, "except as might be required by ordinances in effect pursuant to section 303(b)(1) or adopted pursuant to section 503," and 34 Pa. Code 403.62(c) says "A permit is not required for the exceptions listed in § 403.1(b) (relating to scope) and the following, if the work does not violate a law or ordinance." For residential construction the Zoning Office page says "Verification of state license required," and a Moosic Borough Contractors License, for a fee of $75.00, is required of "Any contractor doing commercial work in the Borough." The Zoning Office and the Code Enforcement Officer keep office hours at the Borough Building on Monday, Wednesday and Thursday from 1pm to 4pm; the Borough Building is open Monday to Friday, 8:30 am to 4:00 pm, at (570) 457-5480. Read for this answer: Chapter 121, Construction Codes, Uniform, of the Borough Code in full; Chapter 124, Contractors, Licensing of; Chapter 181, Licensing and Permits; Chapter 148, Fees; Chapter 15, Code Enforcement Officer; Article IX of Chapter 300, Zoning; every page of a code-wide search for "roof" and for "reroofing," which found no permit provision naming roof work; the Zoning Office and Code Enforcement pages; the building permit application; and NorthEast Inspection Consultants' own pages.