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, Columbia Borough issues building and zoning permits on one Borough application. Section 112-14 of the Borough Code ratifies the Borough's election "to administer and enforce the provisions of the Pennsylvania Construction Code Act," Section 112-15B says "the Code Official and/or Code Enforcement Officer of the Borough of Columbia is authorized to enforce the Code," the Borough's Code Compliance page lists a Zoning/Code Compliance Manager and an Inspector, each with a BCO credential, and the Borough's 2026 permit application says "A third-party review, including inspections, may be required for some projects with an additional fee." Section 112-14 confirms that election "as the Uniform Construction Code contained in 34 Pa. Code, Chapters 401 through 405, as amended from time to time," names no edition, and changes nothing in the code's roofing provisions; the Borough's permit pages name no code edition.
Permit process
The Borough's Permit Applications page (read October 9, 2026) says "AN APPROVED PERMIT IS REQUIRED BEFORE ANY WORK BEGINS" and lists, under "Zoning Permit would be required for the following," the entry "Roof Replacement / Repair (building permit required if more than 1/2 plywood removed)." That is a zoning permit, a separate Borough permit from a building permit under the Uniform Construction Code; expect to need it for a reroof, and a building permit as well where more than half the roof plywood comes off. The Borough's 2026 fee schedule prices a zoning permit at $50 under Section 220-7 and lists a "Penalty for doing work without a valid permit" of $500. Section 220-3B of the Borough's zoning chapter says "Ordinary repairs and maintenance to existing structures shall not by itself be regulated by this chapter." Article V of Chapter 112 of the Borough Code, Uniform Construction Code (Ord. No. 734, June 14, 2004), names no roof work either way and adds no permit clause for residential repairs or alterations, and no Borough building code ordinance from before the Uniform Construction Code was found in the published Borough Code. The fee schedule's building permit lines are priced by project cost ("First $1,000.00" $50, "Each Additional $1,000.00" $10) and name no roof work, and the application's Description of Work boxes include "Roof Construction." 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." In the Borough's historic district, Section 130-15 of the Borough Code says "Action requiring a certificate of appropriateness is any activity requiring a building permit," and the application asks whether the property is in the HARB district and whether the work is visible from the right-of-way. The application also requires a contractor general liability insurance certificate and says "A fine of $500 will be issued if a project begins without an approved permit." Borough Hall is open Monday to Thursday, 8 a.m. to 4:30 p.m., and Friday, 8 a.m. to noon, at 717-684-2467. Read for this answer: Chapter 112 of the Borough Code, Existing Structures, Property Maintenance and Fire Prevention, Articles I to V (Sections 112-1 to 112-15), including Article V, Uniform Construction Code, in full; Article I of Chapter 220, Zoning; Article V of Chapter 130, Historic District; Chapter 116, Fees; the Code's disposition list; every page of a search of the whole Borough Code for "roof" and for "reroofing," which found no code section naming a permit for roof work; the Permit Applications and Code Compliance pages; the 2026 Building and Zoning permit application; and the 2026 fee schedule.