How to reseal a caravan


My 2 little helpers
My 2 Little Helpers

The old tragic story of a badly sealed caravan vs its arch enemies damp and rot, but for a change this one has a happy ending.

The first step in reclaiming our caravan and turning it into an office was to make it watertight again. At first it seemed a fairly simple project but once you begin a job like this be ready to take a couple of steps backward before you can move forward again.

The starting point was to remove the caravan rails to get them sealed up again. This is not an easy job, especially in a caravan as old as our. Once the rubber seals were peeled away you could see how rusty the screws holding it in place were. Only about 1 in 4 came out easily most of head on the others were either no longer visible or disappeared as soon as you touched them with a screw driver. After looking at the options on the internet I went out and bought a Dremel. Other cheaper options are available from eBay, but I wanted something that day. Using a metal grinding bit I ground a deep groove in each screw and then removed them using a straight head screw driver. Its a long job but it works.

Then I removed the rails, cutting through the many layers of silicon that were holding them on and being as careful as I could to not bend them (to much). The previous owners were kind enough to cover all the rails with bathroom silicon instead of resealing them correctly, this made the job a huge amount more time consuming.

At this point i saw the damage to the frame and thought what have I done! You could clearly see the rot on the lower parts of the frame and when I removed the last rail part of the frame actually disintegrated. This was panic stations. The only way to fix it was to pull out the seats and remove the internal walls of the caravan. It was rotten so I went and bought a dehumidifier, which I knew would be handy for when it was being used as an office and then started to make a plan. I had some left over fencing wood in the garden which I used the rebuild the frame to the best of my ability the thinking behind this was

  1. Because it was there and free
  2. If any damp did get in the treated timber would last a lot longer
  3. Did I mention it was free?

Just so you know I completely winged the rebuilding the frame, I don’t have any joinery experience so I simply looked at the pieces coming out and recreated them or took a guess what they might of looked like before the disappeared with rot. I also added some extra supports just to be sure. The caravan felt much more solid when I’d finished, not surprising as it only had half frame at the start. When the frame was rebuilt it was time to get on with the re sealing.

Next step was the removal of the silicon and mastic. The silicon was the hardest but I ended up using a razor blade in a similar way to a scraper to cut the silicon off and remove most of the mastic. When that was done the rest of the mastic was removed by washing it with white spirit and steel wool. When the caravan was clean i started on the rails. The last step was to clean everything with methylated spirits to remove the white spirits which would stop the new mastic from sticking properly.

The loose parts of the shell were tacked on with panel pins and then new mastic was applied to the seams then the rails were reattached with the addition of a few more screws. At the beginning I was really unsure what I was doing by the end I would be happy to take on the job again. And most importantly I new that the caravan was water tight.


Mastic applied and ready for the rail to be reattached

Next Step -> Remodelling the Inside.

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