Discovering the leak

When I opened the back doors of the van the other morning, I noticed something unusual about the mattresses for my pullout bench/bench. All three of the mattresses were soaking wet at the end nearest the doors, and so was the bed underneath.

Luckily the water had been absorbed and hadn’t made it to the floor, but I needed to know why this had happened, and how to stop it happening again. I was relieved that the walls were dry, but noticed the ceiling by the back door felt wet.

How the water got in

My first thought was that it was the plugs which cover the roof bar mounting holes. But I had sealed them in and they were still intact.

My next guess was that the rubber u-channel seal on the doors had failed but it wasn’t that either, and the doors were completely dry.

Next, I checked the door seal which runs around the entirety of the back door opening. There were no cracks, holes, tears or anything else that might cause concern.

So, I pulled the seal away to check underneath and find where the water had got in. There was a damp patch just on the curve, so the water must have found its way in under the seal and dripped onto the mattresses all night.

Why the water got in

After working out how the water got in, I wanted to work out why it had got in, but before I got a chance, more heavy rain came along so I put the seal back on, took the mattresses inside to dry and left a bowl on the bed to catch any water.

Unfortunately, it did.

The next morning there was water in the bowl, as well as a very obvious location of entry on the ceiling.

There were 3 things that I noticed might be causing the problem, and a very important fourth one which I’ll go into later.

The first was the amount of dirt on the van. This really wasn’t doing the seal any favours.

The second was the excess carpet which I had tucked over the metal to be covered by the seal – the carpet overlap here appeared to be wet.

Thirdly, the contact adhesive overspray leftover from the carpet clearly didn’t allow the seal to sit flat on the metal.

Fixing the leak

When it was time to get started, I pulled the seal again and began cleaning the seal – inside and out.

The next step was to clean all along the metal lip, first with water to remove the dirt and then with white spirit to get rid of the glue. The white spirit also helped to loosen up the carpet ends, which I could now trim back in areas they were too long.

I wasn’t worried about it being neat, as it would all be covered by the rubber seal – I just wanted there to be less carpet overlap.

As I came to refit the seal, I made an interesting discovery, which is the fourth potential reason for the leak. I discovered that the rubber seal actually has thin, pliable metal running all the way through it, so it can be opened or closed more to fit the object it is attached to.

With this in mind, before refitting the seal, I went round it and closed its gap with my hands. Then, I could fit it to the van, tapping it firmly in place with my hand, for a tight – and hopefully water tight – fit.

Testing the fixed leak

And there was only one way to find out…so I put the bowl back in the van and tipped a bucket of water over the roof. I also set up a camera in the van to create possibly the world’s most boring time lapse and, happy that the seal had kept the water out, I put the mattresses back in.

The real test came when, a couple of days later, another lot of heavy rain was forecast. I left the camera timelapsing away in the van overnight, and I’m pleased to report that no water has ingressed into the van! Hopefully that’s solved the leaky door seal problem, but I’ll be sure to report back if I have any further issues.

If you want to see more of my camper van build in action, please CLICK HERE.