You can see the top layer of timber covering the insulation has discoloured with damp. Thankfully it started to harden out as it got higher. The damp (water) appears to have collected in the lower section and began its rot from the end upwards. The section 18” or so from the floor is reasonably sound. Likewise as it enters the main framework of the van.

WHAT NEXT

The advice from the Wizard and others was to check the usual suspects, that is: Any damage to the external bodywork of the caravan itself - Window seals - Doors - in fact any exposed joint or seal. Nothing obvious there, move onto our prime suspects, the rails. Awning rail (numero uno) and the rails covering the other panel joints on the exterior.
     From the photos I sent the Wizard he was fairly certain the awning rail was the problem. Wizard then gave me detailed instructions on how to start.
     No easy way to do this. From the location of the damp it was almost certain as Wizard had said, that the water was coming in from under the awning rail. It had to come off. (Fears of tackling such a job can be allayed by checking out the work the others have completed on the ‘Links’ page).
     The caravan had to be brought home, tight driveway or not. Too much work to be carried out at the storage yard and I needed the electricity for my tools. It was a squeeze and the van had to be manually pushed in A frame first so I could have access to the suspected side.
     Before starting work: The essential list of items I would need to eventually replace the front awning rail section which would be the first point to check. These included 1 tube of ‘Seamseal’, a non-drying sealant (really messy stuff). A 5 metre length of 32mm Caravan Mastic strip. 2 tubes of ‘Sikaflex’ sealant and a box of screws (‘Spax’ 3.5X30mm from B&Q). Rolls of 2” duct tape, Ronseal Wood Hardener and White Spirit. Cost: just over £20 in total.
     The awning rail is in two sections on our caravan and I was hoping that by removing the front piece I could find and fix the immediate problem without taking the whole thing off.
     First off the plastic piping covering the screws of the rail was eased out as far as the awning rail joint, mid-way along the top side.

Removal was easier than I expected thanks to the fact that the screws were not too badly corroded and came away without damage. The rail came cleanly away without problem. Note:This a definitely a two person job. All too easy to bend the rail if you try and do it alone.
     The slap-dash way the mastic had been originally applied to the point where the rail curves down toward the front was apparent as you can see in the photo. Gaps everywhere!

The rust stains from the staples can be seen forward of the first lean area indicating the start of the water ingress.

UNVEILED

Awning rail removed, the true extent of the problem is revealed. This is the section just back from the start of the downward curve. Again, rusty staples below the patchy mastic betray the water entry points.

   The bottom front section.

   The cleaning of the old mastic and sealant wasn’t as much of a problem as I thought it was going to be (the way it was originally applied helped a bit;>). Using a paint scraper first and then wiping the area down with a rag soaked in White Spirit had the area clear in a couple of hours.
     Note on White Spirit: Never knew why they called it that, being a clear liquid. Clear that is until it dries out. White patches all over the van where I’d put my mitts! Windows, walls and anything else I touched. It’s the same with me cooking, more mess than the worth of it.
     Anyway, the muck removed I could see obvious areas where water could get in. Sickening to think that the lack of attention to detail by the makers of the caravan during the original build. You can see from the photos below the ‘hide it and be damned’ mindset. In theory, very little if any, sealant should be needed on the joint between side panel and roof due to the fact that the roof panel folds over the side and water doesn’t defy gravity.
     Problems with this caravan stem from the fact that the side sheet was cut short in places and does not go under the folded over roof sheet, leaving a gap. Another manufacturing blunder you can see is where the roof panel curves over toward the front. The sheet pleated on the bend and no attempt to flatten it out or God forbid, cut it properly had been made. The result was that the high rise of the pleats made channels 3/16” deep for water to run into the joint section.

   The photo below shows another ‘cut short’ area where the side sheet is completely missed by the screws through the awning rail where it meets with the GRP front locker.

Nice and clean?

                                                  CLEAN AND DRY

Using ‘Seamseal’, the gaps and uncovered areas were sealed, the lumpy bits flattened down and the caravan was now better than it was when first bodged in manufacture.

The muck removed, the next step could be taken, drying it out. It has to be done so that you can see how much wood has to be replaced and what can be saved or patched. To safeguard against the weather while all the joints were exposed, duct tape was run along the joints to seal.

                                                                      LAST LAP

 I didn’t fancy risking an unattended radiant heater in the van and we don’t have a convector heater so we compromised. The weather forecast was for dry and sunny so the outside temperature would help.
     Drying from the inside out would be by using the ‘Carver Hot Air’ system in the van. Slow but effective. I disconnected the heater air pipe and repositioned it so it was aimed at the problem area and the heat kept in place by replacing the seating. We left it on during the next two or three nights. I also used the Gas stove and our Halogen heater a number of times when I had the time to sit and keep an eye on it. The term ‘Sweatshop’ springs to mind.

   
It took a week for us to be sure it had dried out enough to start repairs. Readings from the damp meter showed very little signs of damp inside where previously they had. Apologies for the lack of photos from here on; To be continued.
     The timber in the front locker dried out effectively and so I was able to start work. The rotten section of timber spar that was under the aluminium sheet was cut out and replaced. We were fortunate in the fact that only about 18” or so of the spar was damaged beyond repair. As I said earlier, the rot was working back from the water’s journey’s end in the front locker and had not reached into the main structure of the van or indeed far up the main framework.
     The inside panels will be removed at some future date (If she lets me) but there seems to be no reason at the moment to think that there is a problem.
     One short length of 2” x 1” batten cut and mitred to fit was used to replace the removed section and glued and fitted together to the existing piece. Ronseal wood hardener was then applied to the sound but ‘at risk’ higher section and the whole lot painted with a preservative paint. An off-cut of plyboard replaced the damaged sheet and was glued on using ‘Hard as Nails’. The aluminium sheet was replaced complete with its rubber edging and stapled into position.
     Not quite perfection to look at but a great deal better than before and we now know that underneath it’s solid.
     Sure that this section was now adequately repaired we moved onto the final part of the rebuild. Mastic strip was applied to the awning rail and together we offered it up to its old home. (Don’t even think about trying to do it alone unless you’ve got three arms at least 6’ long). I had pushed in and snapped off a few wooden toothpicks in the screw holes that looked a bit stretched to give added grip to the replacement screws. I did not make any new holes in the rail at this time. Maybe in the future.
     The rail lined up, I lightly screwed the rail back on at a few points as my Wife held the rail level. Easier than expected and looking good.
     Before tightening the screws along the whole of its length I ran a decent sized bead of ‘Sikaflex’ along the top and bottom edges of the rail. I also put a squirt of ‘Seamseal’ around the screws before the final tightening. Doesn’t hurt and it adds to the protection. One thing I did find was that the screws cannot be unscrewed even if lightly biting inside the holes without pulling at the mastic. Even with the advisory ‘spit’ lubrication, they stilled tugged. Nothing that a spot of ‘Seamseal’ or other non-setting sealant can’t fix before the final tightening but it would have been nice to have avoided the problem. One for the diary to be used in ‘Part 2’.
     After the reinstallation of all the bits and pieces and satisfied, that for the moment (fingers crossed) the van would be watertight (from the outside) the rubber piping that covers the screws was replaced and the whole area cleaned up. Ok, so it’s not exactly showroom condition (I was a bit messy with the sealant) but we do know that this particular area will not be a problem for a while. The rest of the caravan with the other sections of rails, window seals, door seals etc, will, in due course, be taken apart and checked. Can you blame us for losing faith in the original builders? I think not.
     Latest: The repaired section appears to be holding and there is no water ingress to the repaired section in the bulkhead but,,,,,,,there is damp still being detected on the interior at the original point. Thoughts? It seems to be coming in via the front windows. Next job(s): Remove, reseal and refit the external rail above the windows. Check the window seals and all surrounding areas. To be continued..