--- title: "How a Converted School Bus Is Repaired Without Plans" description: "Collision work on a skoolie with no build record starts with documentation, not disassembly. How the structure gets reverse engineered before anything is cut." focus_keyword: "how a converted school bus gets repaired without build plans" canonical: https://ocrv.me/blog/the-skoolie-that-arrived-with-no-drawings/ kind: blogPost updated: 2026-07-29 source: OCRV Center --- # The Skoolie That Arrived With No Drawings > With no build record, the first job is documentation. This bus had **two roof ribs cut and sleeved** during a raise, and **house wiring sharing the chassis chase**, neither of them visible. ## How is a converted school bus repaired when there are no build plans? By documenting and reverse engineering the conversion before disassembly, opening a known sound area first to learn how the builder worked. Second owners bring these to our Yorba Linda shop with no paperwork at all, and the drawings we produce go home with the vehicle. - Photograph and trace before removing anything - Open an undamaged area first to learn the builder's methods - Label every conductor with a tone generator before cutting - Expect wood framing, mixed metals and unmarked splices ### Key facts | Item | Value | | --- | --- | | Unit | Converted conventional school bus, 1998 chassis | | Roof ribs found spliced | 2 (Sleeved during a previous roof raise) | | Body and paint labor | $210 per hour | | Mechanical and electrical labor | $260 per hour | | Diagnostic rate for circuit tracing | $285 per hour | The current owner was the second owner. He had bought a finished conversion, used it for two seasons, and been sideswiped in a parking structure entrance, which took out two exterior panels and a window on the driver side. He had no drawings, no wiring diagram, no photographs of the build and no way to contact whoever had done it. That is a common situation and it is not a reason to decline the work. It does change the order of operations completely. On a factory built coach you look up how it was made. On a conversion you find out how it was made, and finding out is a billable operation that has to be in the estimate rather than absorbed halfway through. ## Documentation comes before disassembly The first day was photography and measurement, with nothing removed. Every interior surface, every visible fastener pattern, every seam, every cabinet interior, the electrical panel with its cover off, the underside of the vehicle. Roughly three hundred images, geotagged to a location on the vehicle in the file names, because a photograph you cannot place is not evidence of anything. Then measurement: exterior body dimensions at several stations, interior ceiling height at intervals along the length, window opening dimensions, and the position of every structural member we could locate by magnet and by fastener line. Those numbers became the drawing that did not exist, and by the end of the job they were accurate enough to hand to the owner as a build record. ## Open a sound area before opening the damaged one This is the technique that makes conversion work tractable. Before touching the damage, we removed an interior panel on the opposite side, in an area with no damage at all, purely to learn how this particular builder assembled things. What is the framing material, how is it fastened, is there insulation and what kind, how are the panels attached, is there a vapour barrier, where do the wires run. Twenty minutes on the good side told us more than a day of guessing on the bad side. It also meant that when we opened the damaged area we could immediately identify what was original builder work and what was collision damage, which is the distinction an insurance file lives or dies on. Without the comparison, every unusual thing you find is ambiguous. - Open an undamaged area to establish the builder's normal practice - Record framing material, fastener type, insulation and wire routing - Use it as the reference for what is damage and what is construction - The comparison is what makes a supplement defensible ## The two roof ribs that had been cut This bus had a raised roof. The builder had cut the original roof ribs at the belt line, added a section of wall, and rejoined the ribs with sleeves. That is a legitimate approach and it is how most roof raises are done. What we could not establish was the sleeve material, the length of the overlap or whether the splices had been welded all round or only tacked. So we opened two of them, one on each side, in undamaged areas. The sleeves turned out to be adequately sized with full welds, which is good news and would have been unknowable otherwise. That inspection then defined how we spliced the two ribs that the impact had bent: matching the builder's method rather than introducing a stiffer joint that would concentrate load at its ends. ## The wiring, which was the genuinely concerning part The house electrical system ran through the same chase as the chassis harness for about eight feet along the driver side, with no separation and no additional protection where the two crossed. Both were intact and neither had caused a problem, and both were in the exact area the impact had deformed. Two systems in one chase is how a body repair becomes an electrical fault three weeks later. We traced and labelled every conductor in that chase with a tone generator before cutting anything, which took the better part of a day at the diagnostic rate. Eleven of the house circuits had no identification of any kind. The label set we created went into the panel as a printed card at the end of the job, which is a small deliverable and the one the owner mentioned most. > **warning:** House and chassis wiring sharing one chase is common on owner built conversions. Separating them during a repair that already has the area open costs very little and removes a real risk. ## Wood framing behind a steel body The damaged window opening had been reframed in dimensional lumber, screwed to the original steel structure. Wood in that position is not automatically wrong, and it is very often how a conversion gets built by somebody working with woodworking tools. What makes it a problem is the interface: wood against steel with no isolation and no coating traps moisture, and every fastener through the steel is a bimetallic joint with a fastener of a third material. We reframed the opening in steel tube matching the original section, with isolation tape between dissimilar metals and a coating on every cut end. Where we left builder wood in place elsewhere, we noted it in the documentation with a photograph rather than quietly replacing it, because it is the owner's vehicle and a repair is not an opportunity to rebuild somebody else's decisions on somebody else's money. ## What went home with the bus Two exterior panels replaced, one window opening reframed in steel, two roof ribs spliced to match the builder's method, the wiring chase separated into two runs with grommets at every penetration, fusing added at the solar array feed where none had existed, and refinishing across the repaired side with a blend into the panels fore and aft. Plus the paperwork: a dimensioned sketch of the structure as found, a circuit list with the labels we created, and a photograph set organised by location. We do not certify conversions and we do not make declarations about a vehicle's compliance with anything, and the authority on registration or inspection questions is the relevant agency rather than a repair facility. What we can hand over is an accurate record of what is in the vehicle, which is what the next shop will need. ## Questions and answers ### Why open an undamaged area of a conversion before the damaged one? To establish what the builder's normal practice was. Twenty minutes behind a sound panel tells you the framing material, fastener type, insulation and wire routing, which is the reference that lets you separate collision damage from construction choices. Without it, everything unusual you find is ambiguous. ### How is a spliced roof rib on a raised bus assessed? By opening one in an undamaged area on each side to see the sleeve material, overlap length and weld extent. That inspection then defines how a damaged rib gets repaired, because matching the builder's method avoids introducing a stiffer joint that concentrates load at its ends. ### What is wrong with house and chassis wiring in one chase? Nothing fails immediately, which is why it persists. The risk arrives during any body repair in that area, when cutting or deforming the chase can damage both systems at once. Separating the runs while the area is already open costs little and removes a fault that would otherwise appear weeks later. ### Is wood framing in a bus conversion a defect? Not inherently, and it is common on owner built vehicles. The problem is the interface: wood against uncoated steel traps moisture, and fasteners through both create bimetallic joints. Where wood is replaced, isolation between dissimilar metals and coating on cut ends matter more than the material choice itself. ### What documentation should come back with a repaired conversion? A dimensioned sketch of the structure as found, a circuit list with any labels created during the work, and a photograph set organised by location on the vehicle. That record is what the next shop needs, and on a conversion it usually does not exist until somebody makes it. --- Source: [OCRV Center](https://ocrv.me/blog/the-skoolie-that-arrived-with-no-drawings/). Last verified 2026-07-29.