Resources / Reference
RV Collision Repair Glossary
Every term that appears on an RV collision estimate, defined in plain language. This exists because an estimate written in trade vocabulary is unreadable to the person paying for it, and no other shop in this market publishes one.
Construction
- Azdel
- A polypropylene composite substrate used behind RV sidewall skin. Unlike lauan plywood it does not absorb water, so a leak causes bond failure rather than rot.
- Lauan
- A thin tropical plywood used as sidewall substrate on many coaches. It absorbs water, swells and rots, which turns a bond failure into a substrate replacement.
- Filon
- A brand of fiberglass reinforced panel widely used as RV exterior sidewall skin.
- Front cap
- The moulded fiberglass assembly forming the front of a motorhome or towable. Contains compound curves and moulded features that are difficult to reproduce in a repair.
Damage
- Delamination
- Failure of the adhesive bond between an RV skin and its substrate, appearing as bubbles, waves or soft areas. The visible symptom is always smaller than the actual failure.
Finish
- Gelcoat
- The pigmented outer resin layer on a fiberglass panel. It is sacrificial and oxidises over time, protecting the laminate beneath it.
Diagnosis
- Tap test
- Acoustic testing across a laminated panel. A sound bond returns a sharp tone, a debonded area returns a dull one, and the boundary between them is mappable.
Repair method
- Scarf
- Tapering the edges of a fiberglass repair over a wide margin so new laminate overlaps in layers instead of butt joining. A butt joint becomes a stress riser and cracks.
Estimating
- R and I
- Remove and Install. A part is taken off and refitted, not replaced. Distinct from R and R.
- R and R
- Remove and Replace. The part comes off and a new one goes on.
Insurance
- Supplement
- A documented addition to an approved estimate covering damage discovered after teardown. It is the carrier being shown what was actually broken, not a shop adding charges.
- Betterment
- A deduction a carrier applies when a repair replaces a worn part with a new one, on the basis that the owner ends up better off than before the loss.
- ACV
- Actual Cash Value. Replacement cost minus depreciation. The figure a carrier compares repair cost against when deciding total loss.
- Agreed value
- A policy where the payout figure is set at inception rather than calculated at claim time. Common and worth having on collectible and heavily upgraded coaches.
- Total loss threshold
- The percentage of actual cash value above which a carrier writes a vehicle off rather than repairing it. Varies by carrier and by state.
Structure
- Diamond
- A frame that has gone out of square in plan view, usually from an off centre impact. Aligning axles to a diamonded frame will never make the vehicle track correctly.
- Outrigger
- A member cantilevered off the main frame rail that carries the sidewall. The weld at the rail is a fatigue point and the most common structural failure on towables.
- Crossmember
- A frame member spanning between the rails, carrying the floor. Fatigues where slide cutouts removed material from the middle of the span.
- Datum point
- A published reference location used to measure a frame or unibody against factory specification. Measurement against datum is what makes structural repair verifiable.
Slide systems
- Schwintek
- An in wall rack and pinion slide system driven by motors at each side. Common failure modes are synchronization loss, rail wear, controller fault and motor fault, and telling them apart determines the cost.
- Above floor slide
- A Lippert slide mechanism mounted above the floor line, generally more accessible for service than an in wall system.
- Flush floor slide
- A slide design where the room floor sits level with the coach floor when extended. More complex mechanically than an above floor system.
Roofing
- EPDM
- A synthetic rubber roof membrane. Flexible, repairable and the most common RV roof material. Chalks over time as a normal part of its life.
- TPO
- A thermoplastic roof membrane. Heat weldable, generally more puncture resistant than EPDM and increasingly common on newer coaches.
Sealants
- Dicor
- A common brand of RV roof sealant. Self levelling formulations are for horizontal surfaces and non sag formulations are for vertical ones. Using the wrong one is a frequent cause of a failed reseal.
- EternaBond
- A butyl based sealing tape used on roof seams and penetrations. Effective but essentially permanent, which matters if the surface underneath later needs access.
Electronics
- ADAS
- Advanced Driver Assistance Systems. Radar, cameras and ultrasonic sensors aimed relative to the vehicle structure. Recalibration after structural repair is mandatory, not optional.
Refinish
- Blend panel
- An undamaged adjacent panel that receives new colour so the repair has no hard boundary. Skipping the blend is why some repairs are visible in certain light.
- Downdraft booth
- A paint booth where filtered air moves top to bottom, carrying overspray away from the surface. Booth length is the practical limit on what coaches a shop can refinish.
Process
- Teardown
- Disassembly of damaged areas to expose the true extent of damage before the final repair scope is set. On laminated coaches it routinely more than doubles the visible damage.
Frequently Asked Questions
Why does a body shop publish a glossary?
Because RV collision repair has a dense private vocabulary and an estimate written in it is unreadable to the person paying for it. If you do not know what betterment or R and I means, you cannot evaluate the line items.
Which terms cost people the most money when they do not know them?
Betterment, depreciation and R and I. All three appear on estimates and settlements and all three change what you actually receive.
Is this specific to RVs?
Mostly. Construction terms like Azdel, lauan, Filon and front cap are RV specific. Insurance and structural terms apply to any collision claim.
Terms you will see priced: posted labor rates and hour ranges. Claim vocabulary in context: teardown and supplements explained.
We Can Help. Contact Us Today.
Bring the vehicle to our Yorba Linda facility and we will document the damage properly, work directly with your carrier, and give you a written figure built from published rates and real labor hours.
All work is performed at our Yorba Linda facility. We do not offer mobile, roadside or fleet route service.