In our regular Maintenance Matters column, industry expert Andrew Tapp (RV Inspections Ltd) shares his top tips and personal observations from 20+ years in the motorhome industry.
Pressure testing for RVs has been used in the United States for more than 20 years to identify leaks, and more recently by some manufacturers in Australia. Now it’s coming to New Zealand.
A specialised machine forces air into the cabin through a roof vent, pressurising the inside of the RV – barely above ambient air pressure – to force air outward through any exterior faults.
A soapy solution is then applied to the entire exterior: every seal, every seam, every fitting, every edge. Wherever there’s a breach in the sealant – no matter how small – air escapes and creates bubbles.
The principle is elegantly simple and the results are remarkably precise.
Think back to blowing bubbles as a kid. You dip the wand, put it to your lips, and breathe out – just enough pressure for the soap film to expand into a sphere. Pressure testing on RVs works on exactly the same principle, just on a much larger scale.
It’s the same logic gas fitters use to test pipe fittings under pressure, or the method mechanics use to find punctures by submerging inner tubes in water. Proven. Reliable. Precise.
What Makes This Method Different
The critical advantage of pressure testing is precision. Unlike a visual inspection or a moisture test, it identifies the exact point of entry – not where water ends up, but where it gets in. That changes everything. Repairs become targeted rather than speculative. You fix what actually needs fixing, not what might need fixing.
Because the pressure is so low and so precisely controlled, there’s no risk of damage to your RV. It cannot be over-pressurised. The machine is calibrated to find leaks well before any visible or physical signs appear – such as soft spots, staining, bubbling paint – which is exactly the point. You want to find a failing seal before water does.
Introducing BubbleProof Pressure Testing
RV Inspections NZ Ltd has spent considerable time researching, designing and refining our own pressure testing machine. This isn’t an off-the-shelf unit but rather purpose-built for the specific construction characteristics of the motorhomes and caravans we see here in New Zealand.
After more than 23 years building, repairing and inspecting motorhomes and caravans across New Zealand, I’ve seen the same story play out more times than I care to count. An owner brings in their motorhome or caravan for a repair – soft walls, a musty smell, a mysterious stain on the ceiling – and what I find behind the panels can be catastrophic. Wood rot, delamination, mould.
The frustrating part? It was preventable. And now, RV Inspections NZ Ltd has its custom-built own technology to prevent it.
Here’s why we believe it will become the most important maintenance test you book all year.
The Cost of Doing Nothing
Water damage is the most insidious problem in the RV world. It can go undetected for weeks, months or years – quietly spreading through walls, floors and structural framing long before it surfaces as a visible symptom. By the time most owners realise something is wrong, the damage is already extensive.
The flow-on consequences go beyond the repair bill. Prolonged moisture creates mould – a serious health risk, and a problem that requires professional remediation on top of structural repairs. Wet timber rots. Delamination spreads. Electrical systems become compromised. Flooring fails. If you’re planning to sell, water damage – or even the suspicion of it – is the fastest way to destroy resale value.
Early detection is everything. A failed seal caught in the BubbleProof Pressure Test costs a fraction of what it costs to repair the damage that follows if it’s missed.
Why Leaks Are So Hard to Find
Your RV is not a single, solid structure. It’s a complex assembly of different panels, frames, fixtures and materials – all bonded and sealed together with adhesives and sealants. Every window, vent, aerial mount, roof rack bracket and body seam is a potential entry point for water.
Add to that the brutal conditions a New Zealand RV endures – summer UV baking sealants brittle, corrugated back roads flexing and twisting the body in ways most owners don’t realise. Over winter, motorhomes and caravans often sit idle for months – expanding and contracting through cold nights and warm days. It’s a recipe for micro-failures that are completely invisible to the eye.
Even experienced repairers struggle to locate leaks with any certainty. Spray testing with a hose is unreliable – water follows unpredictable paths and the entry point can be metres from where the damage appears. Resealing everything and hoping for the best wastes thousands of dollars and still doesn’t guarantee you’ve found the problem. We’ve seen owners go through multiple rounds of expensive repairs, only for the leak to persist.
When Should You Test?
We recommend BubbleProof Pressure Testing as an annual test – and the timing matters. Right now, heading into winter, is exactly the right moment to book in. Your RV has just come off the back of a hard summer: UV, heat, long trips, rough roads. All of that puts sealants under stress. Before you park up for the cooler months, you want to know your RV is watertight – because a slow leak left undetected through a wet New Zealand winter can do serious damage before you even pull the covers off in spring.
We also strongly recommend BubbleProof Pressure Testing before you put your RV up for sale. It gives the buyers the confidence of knowing exactly what they’re getting into – and gives sellers a documented clean bill of health that adds credibility and value.
Your RV Deserves Better Than a Guessing Game
A sealant breach costs next to nothing to fix when you catch it early. Leave it six months – through a wet New Zealand winter, parked and forgotten – and you’re looking at structural repairs, mould remediation, and a resale value that takes a serious hit. Sometimes all three.
Pressure testing finds leaks before the damage happens – before the repair becomes a gut-job, before the insurer questions whether the damage was gradual wear and tear, before the resale price takes a hit.
Pressure testing is well overdue in New Zealand. The technology exists, the method is proven internationally, and there’s no good reason our RV owners should be without it. We built BubbleProof because we got tired of seeing so much preventable damage.
We expect pressure testing to become a standard part of the annual RV service schedule – and to be increasingly requested by buyers as a non-negotiable part of second-hand motorhome and caravan sales.
The first time it finds a leak you didn’t know you had, you’ll understand why.
