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, Walker Township's Building and Zoning Permits page says its Building Permit Officer is "responsible for processing building permit applications" and for "making necessary inspections to ensure that construction is completed in compliance with the Pennsylvania Uniform Construction Code (UCC) and any special provisions the Township may enact by ordinance in addition to the UCC." Section 5-101 of the Township Code (Ord. No. 2004-1, June 7, 2004) says the Township "hereby elects to administer and enforce the provisions of the Pennsylvania Construction Code Act" and adopts the Uniform Construction Code "as amended from time to time" by reference "as the municipal building code of this municipality." The Township office is at 9698 William Penn Highway, Thompsontown; its Contact Us page says "Hours are by appointment." Part 1 of Chapter 4 of the Township Code, the Walker Township Building Permit Ordinance (Ord. No. 11/3/1975), names no roof work. Section 4-105 says it "shall be unlawful to construct, enlarge, alter, remove or demolish" any building "without first filing an application in writing with the Building Permit Officer," and Section 4-104 says "The regulations contained herein shall not apply in the case of repairs; said term being defined as painting or the normal regular repairs to a building aggregating $2,000 or less in value." Section 5-101(5)(A) keeps in effect building code ordinances adopted on or before July 1, 1999 "which equal or exceed the requirements of the Code." Section 27-1302 of the zoning chapter says it is unlawful to commence "the moving or alteration of any building" until the Zoning Officer has issued a building permit, but "No permit shall be required for repairs to or maintenance of any building, structure or grounds, provided such repairs do not change the use or otherwise violate the provisions of this chapter." The Township's pages and Chapters 4 and 5 of its Code name no code edition.
Permit process
No Walker Township text read names reroofing as permit work or as exempt. Part 1 of Chapter 4 of the Township Code, the Walker Township Building Permit Ordinance (Ord. No. 11/3/1975), names no roof work. Section 4-105 says it "shall be unlawful to construct, enlarge, alter, remove or demolish" any building "without first filing an application in writing with the Building Permit Officer," and Section 4-104 says "The regulations contained herein shall not apply in the case of repairs; said term being defined as painting or the normal regular repairs to a building aggregating $2,000 or less in value." Section 5-101(5)(A) keeps in effect building code ordinances adopted on or before July 1, 1999 "which equal or exceed the requirements of the Code." Section 27-1302 of the zoning chapter says it is unlawful to commence "the moving or alteration of any building" until the Zoning Officer has issued a building permit, but "No permit shall be required for repairs to or maintenance of any building, structure or grounds, provided such repairs do not change the use or otherwise violate the provisions of this chapter." The Township's Building and Zoning Permits page describes the Building Permit Officer's duties and names no roof work, and its Land Use Permit Application (a scanned form) has a line "Building Permit Required" with Yes and No choices and no roofing line. Whether Section 4-105 reaches an ordinary reroof turns on whether the job is an alteration, which no Township text read settles, so this record does not decide whether the Township requires a permit for an ordinary 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." Walker Township's Building and Zoning Permits page says its Building Permit Officer is "responsible for processing building permit applications" and for "making necessary inspections to ensure that construction is completed in compliance with the Pennsylvania Uniform Construction Code (UCC) and any special provisions the Township may enact by ordinance in addition to the UCC." Section 5-101 of the Township Code (Ord. No. 2004-1, June 7, 2004) says the Township "hereby elects to administer and enforce the provisions of the Pennsylvania Construction Code Act" and adopts the Uniform Construction Code "as amended from time to time" by reference "as the municipal building code of this municipality." The Township office is at 9698 William Penn Highway, Thompsontown; its Contact Us page says "Hours are by appointment." Section 4-110 sets a fine of "not less than $10 not more than $1,000, plus the costs of prosecution," and says an owner who fails to comply "shall also be billed for real estate taxes from the time such construction or improvements are commenced." Ask the Township office, which is open by appointment, before starting a reroof. Read for this answer: Chapters 4 and 5 of the Township Code in full, Part 13 (Administration and Enforcement) of the zoning chapter in full, and a search of the whole Township Code for "roof," for "reroofing," for "shingle" and for "reshingling" and every page of a search for "repair"; the Township's Building and Zoning Permits, Forms and Applications, Contact Us and floodplain pages; and its Land Use Permit Application (a scanned form, read from the rendered page images). The Township has published no permit fee schedule or building permit application, and Section 4-106 says the building permit fee is "as set forth by the Township Supervisors in a resolution."