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, Raccoon Township's Municipal Office is at 1234 State Route 18, Aliquippa (724-495-6587), and its Zoning & Permits page says "Please contact the township office prior to any construction to verify if a permit is needed. Our inspections are performed by MDIA, Inc 1-800-580-6342." Section 83-1 of the Township Code says the Township "elects to administer and enforce the provisions of the Pennsylvania Construction Code Act," and Section 83-3 B lets it use "the retention of one or more construction code officials or third-party agencies." The "Building Permit App" the page links carries an "MDIA Office" block. Section 83-2 of the Township Code (Chapter 83, Construction Codes, Uniform, Ord. No. 04-1, effective July 1, 2004) says "The Uniform Construction Code, contained in 34 Pa. Code, Chapters 401 through 405, as amended from time to time, is hereby adopted and incorporated herein by reference as the municipal building code of the Township of Raccoon," and Section 83-5 keeps in effect building code ordinances adopted on or before July 1, 1999 "which equal or exceed the requirements of the code." The chapter adds no permit clause of its own for house repairs and names no roof work. Section 185-69 A of the Township's Zoning chapter says "No building or structure, including mobile homes, shall be erected, added to, or structurally altered until a permit therefor has been issued by the Zoning Officer" and exempts "Remodeling or improvement of an existing building that does not alter the basic structure, create additional lot area coverage or change the use of the parcel or building," and Section 185-69 C(1) says "No permit shall be required for the following:" "Minor repairs or maintenance." Neither names roof work, and this record does not decide whether a house reroof is a minor repair or maintenance, or needs a zoning permit. The Township's Zoning & Permits page says "Raccoon Townships follows the 2015 Uniform Construction Code" and Chapter 83 of the Township Code names no edition and adopts the code "as amended from time to time"; this record has not read the 2015 edition's text and does not decide which edition the Township applies.
Permit process
Raccoon Township's code and pages read for this record do not say whether a house reroof needs a permit. Section 83-2 of the Township Code (Chapter 83, Construction Codes, Uniform, Ord. No. 04-1, effective July 1, 2004) says "The Uniform Construction Code, contained in 34 Pa. Code, Chapters 401 through 405, as amended from time to time, is hereby adopted and incorporated herein by reference as the municipal building code of the Township of Raccoon," and Section 83-5 keeps in effect building code ordinances adopted on or before July 1, 1999 "which equal or exceed the requirements of the code." The chapter adds no permit clause of its own for house repairs and names no roof work. Section 185-69 A of the Township's Zoning chapter says "No building or structure, including mobile homes, shall be erected, added to, or structurally altered until a permit therefor has been issued by the Zoning Officer" and exempts "Remodeling or improvement of an existing building that does not alter the basic structure, create additional lot area coverage or change the use of the parcel or building," and Section 185-69 C(1) says "No permit shall be required for the following:" "Minor repairs or maintenance." Neither names roof work, and this record does not decide whether a house reroof is a minor repair or maintenance, or needs a zoning permit. 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." Ask the Township office (724-495-6587) before starting; its Contact Us page gives office hours of Monday to Thursday 8 am to 4 pm and Friday 7 am to 3 pm. Read for this answer: the Township's Zoning & Permits, Forms, Contact Us and Municipal Office pages; its Building Permit App, Zoning Permit App and Single Family Dwelling Guidelines (the last scanned, read by text recognition); and on eCode360 Chapter 83 (Construction Codes, Uniform, in full), Chapter 185 (Zoning, in full, including Section 185-69), and every page of a search of the whole Township Code for "roof" (15 results, none a permit provision for roof work) and for "reroofing" (no results). Several chapters' cross-references name a "Chapter 73" on building construction that did not appear in those searches.