Park Model RV Repair for Sited and Seasonal Units

A park model is built to a recreational park trailer standard and kept under four hundred square feet so it stays in that category. It has residential windows, a pitched roof, real insulation and, once sited, permanent water, sewer and power. The axles exist to get it to the site and, for most units, will never be used again.

That single fact reorganises the whole repair list. We are not looking for membrane seams, butyl shrinkage or road vibration. We are looking at how the unit is supported, how a residential roof detail is holding up, and what fifteen years of ground moisture under skirting has done to the floor perimeter and the frame.

• Under four hundred square feet by design
• Residential roof, windows and insulation details
• Sited on blocks or piers, then skirted
• Axles used once, sometimes twice, in the unit's life

On the road a trailer frame is supported at the axles and the coupler, and the rails were engineered for exactly that. Sited, it is supported wherever the installation crew placed the stacks, which is frequently determined by the ground rather than by the frame drawing. Point loads land where the rail was expecting to be a span.

Add ground moisture, and those point loads are also where corrosion concentrates, because a block stack traps damp against the rail. Fifteen years later the unit has a slight sag between supports, doors bind at one end, and the crack in the drywall that the owner has been patching is telling them about a frame.

An RV roof is one membrane with everything sealed on top of it, and it is checked by looking at sealant. A park model roof is shingles or standing seam metal over a pitched deck, with flashing at wall junctions, valleys and any porch tie in, and those details work by lap direction and step flashing rather than by sealant.

Nobody inspects them, because owners think of the unit as an RV and RV maintenance means checking sealant. So the flashing at a wall junction quietly fails and the water runs inside the wall rather than appearing on a ceiling. When we assess one of these we look at the roof the way a roofer would, not the way an RV technician would.

Skirting is fitted for appearance and for freeze protection, and unless it is properly vented it produces a humid unventilated cavity under the floor. Ground moisture rises into that cavity, has no route out, and sits against the underside of the floor perimeter and the base of the wall framing continuously.

This is the single most common serious finding we make on a park model, and it is completely invisible from inside until the floor goes soft near an outer wall. Correct venting, a ground vapour barrier and clearance at the skirting base are the preventive measures, and they cost almost nothing next to a floor perimeter rebuild.

1. Lay a ground vapour barrier under the entire footprint
2. Vent the skirted cavity on opposing sides for cross flow
3. Keep the skirting base clear of standing soil and mulch
4. Inspect the floor perimeter from inside the cavity annually

A park model is engineered for delivery, not for travel, and after fifteen years sited it is a structure that has taken a set on its blocks with rails that have corroded at the support points. Asking it to be a trailer again for one afternoon puts loads into it that it has not seen since it was new and cannot necessarily take now.

The failures happen in a single trip: drywall cracks, window flashing laps break open, the roof to wall junction moves, and occasionally a rail buckles at a corroded point. A pre move assessment is genuinely worth the diagnostic hours, because the alternative is discovering the frame condition with the unit halfway to its new site.

Structural, roof, body and interior work bills at $210 per hour with body supplies at $5 per body hour and paint supplies at $55 per paint hour. Plumbing and electrical work is $260 per hour. Assessment is $285 per hour with a one hour minimum, credited in full against an authorized repair.

Owners are seasonal residents, retirees and park operators managing several units. The practical constraint is honest and worth repeating: this work happens in shop at Yorba Linda, so a sited unit has to be transported here as a permitted oversize load, and for many owners the assessment is the useful service we can provide rather than the repair.

Most park models never come to us, and that is a genuine limitation to state plainly: they are sited, skirted and connected, and there is no mobile service and no on site option from this facility. What we do handle is units brought in on a transport, and at twelve feet wide a park model is an oversize load that needs a permitted move and a scheduled arrival. Inside, a forty foot park model fits the bays and the booth, and it is supported on the frame at the designed points rather than on the block layout it arrived with.