Tackling the roof

It's been kind of helpful to have had a break, so I could decide how to approach the roof - waterproofing, strengthening and dealing with the rot and damp.

First step is removing the top rail on the left side. I am sticking only to the most damaged left side. The rail is in 2 sections meeting in the middle. I will concentrate on the front half. The rubber cover is removed first, this is part missing and is not worth keeping. Only the bottom end screw fails to budge and this is easy to just pull because the section of wood behind there is rotten.

There is a mixture of hard and soft sealant, and it is a messy and time consuming job to clean all this off the van and the rail (which is reusable).

Then to look at the aluminium underneath, unfortunately there is some poor workmanship hidden here. For a fair stretch the aluminium bent over the top edge does not meet the side panel, explaining the leak. This is probably made worse by possible swelling of the wet wood underneath. Also at various points there are nails though the aluminium and these are corroded (not stainless), even a large corroded screw, no idea why and this also caused a leak.
What I want to do is get at the wooden frame from the side so I can secure new wood cross struts. It was not immediately obvious how I would do this, not able to peel away the aluminium once I freed it from the roof. I carefully use a hammer and chisel to bend the top 2 inches over giving me access (and exposing wet wood).

I can't get very close to the middle as the back half of the rail is still in place. I finally bought a decent tarpaulin and tie this over the entire roof before quitting for the day.

Still foggy but not raining in the morning and to my surprise the wood is starting to dry out under the tarp. I plan to work slowly across the ceiling today replacing wood and dealing with issues as I go. First, I attempt to remove the ceiling ply embedded in the wall - this is actually pretty hard to do as it is soggy and stapled the wood below. I get past halfway before returning to the plan. It strikes me that the gap revealed by the ply removal could be a blessing, if I can squash the roof down, this will allow the aluminium sheets to overlap properly. But the roof wood is screwed into the wood below so I can't just hammer it down- I try, no doubt damaging the wood, fancy I have gained a bit.

I found it was quite easy to remove the cross struts by sawing through the middle and pulling the wood out from both sides (picture above shows the gap left by the ceiling ply and you can see where one cross strut is removed, the one just visible on the right is the front one). They are nailed in the centre and 2 staples held them on the outside. I have made a minor error, the woods are sited in a groove cut out of the edge frame. This means the measurements I gave the builder's merchants are all short. I screw a thin piece of left over wood along the centre, and carry on. Progress is slow, the wood is a bit rotten at the front, but I want to preserve some of it. Its not dry enough to treat yet, so I just have to work around it. By dark I manage to replace 5 of them, cover up the exposed joins outside with duct tape and the tarpaulin. Not many pics, light was bad and I was racing the clock.

2 week gap now.