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, Clearfield Borough, in Clearfield County, takes permit applications through its Code Department at 6 South Front Street, 814-765-7817, and uses a third-party inspection agency: Section 230-1 of the Borough Code says the Borough "hereby elects to administer and enforce the provisions of the Pennsylvania Construction Code Act," the Borough's Forms page posts its "ZONING OR UCC PERMIT APPLICATION," and Pennsafe Building Inspection Services LLC posts "Borough of Clearfield, PA Applications" on its own site, each headed "Borough of Clearfield – PERMIT APPLICATION." Section 230-2 adopts the Uniform Construction Code, "as amended from time to time," "as the municipal building code of Clearfield Borough." Separately, Section 230-14 (Ord. No. 1349, 2018) says "the International Residential Building Code 2015" and other 2015 International Codes "be and are hereby adopted as the codes for application, use and enforcement within Clearfield Borough." Neither names roof work. Section 230-14 names the 2015 editions of the International Codes and the Borough's pages name no edition; this record has not read the 2015 edition's text.
Permit process
No Clearfield Borough text read says whether an ordinary house reroof needs a permit. The Borough's "REQUEST FOR ZONING OR UCC PERMIT" has a "[ ] Roofing" box among its "TYPE OF WORK OR IMPROVEMENT" boxes, beside New Siding, Windows and Fence, and does not say which of those jobs needs a permit. Pennsafe's list of Borough of Clearfield applications includes a "Commercial Roof" packet and no residential reroof packet. The Borough's fee chapter (Chapter 265) sets residential building or zoning/land use permit fees and has no roofing line. Section 230-2 adopts the Uniform Construction Code, "as amended from time to time," "as the municipal building code of Clearfield Borough." Separately, Section 230-14 (Ord. No. 1349, 2018) says "the International Residential Building Code 2015" and other 2015 International Codes "be and are hereby adopted as the codes for application, use and enforcement within Clearfield Borough." Neither names roof work. Section 230-14 names the 2015 editions of the International Codes and the Borough's pages name no edition; this record has not read the 2015 edition's text. Separately, Chapter 276 of the Borough Code (Fire Limits, Ord. No. 295 of 1920) says "No roofs of combustible materials shall be reconstructed or replaced upon any structure within the above described limits," a downtown district bounded by Walnut Street, Fourth Street, Bridge Street and the Susquehanna River, plus strips along Bigler Avenue and Nichols Street. 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." No Clearfield Borough text read says whether an ordinary house reroof needs a permit, and this record does not decide whether the Borough's 2015 code adoption reaches it, so this record does not state the answer. Ask the Borough's Code Department (814-765-7817) before work starts. Read for this answer: Chapter 230 of the Borough Code (Construction Codes, Uniform, Articles I to III, Sections 230-1 to 230-18) in full; Chapter 265, Fees; Chapter 276, Fire Limits; every page of a search of the whole Borough Code for "roof" and for "reroofing"; the Borough's Code Enforcement and Forms pages and its Zoning or UCC Permit Application; and Pennsafe's Borough of Clearfield applications page with its addition and deck or porch packets.