The roof continued

This weekend (20/21 Jan) I wanted to complete the left hand (damaged) side of the roof. I ordered and received from Rainbow Conversions 2 new roof lights/ windows and they have arrived. Recap - I am replacing all the cross struts (20x28mm) with 25x45mm softwood to support double insulation depth.

Saturday morning is bright and cold so I get started. Pleased to find that despite the cold, the wood at the front end (that I worked on last time) has dried out nicely. First step is to remove the rest of the awning rail. This is straightforward and the same as the front half which I did last time. Then I clean off the sealant and turn down the aluminium sheeting to access the wooden frame. Some of this wood is very wet. I start to knock out the remnants of the ceiling ply sandwiched by the frame, this is also wet and difficult to get out.

The first 2 cross struts are easy, after that I have to work harder as this involves the surround of the bad roof window, I also have to remove the ceiling panelling on the opposite side a bit to get access to the centre rail. This reveals some hidden damp on the other side, probably from the second roof window. I try to pull out the cabinet reaching to the ceiling on the right. This is only partially successful as I can't get the heater off the floor, it must be bolted through - save that one for another day. I leave for the day with quite a few woods not in place, and the old window resting in place with a bit of duct tape, and the tarpaulin pulled over the whole lot.

It's really cold on Sunday morning, never mind - at least it's dry. I crack on installing the missing wood cross struts, slowed a bit by picking out the wet ceiling ply. Now it is snowing lightly, great... The new window frame is in place by lunchtime. Then cleaning off the old sealant on the roof, it's hard to get off! Succeed after quite a bit of effort with a blade, white spirit then meths. It is good to get the new roof window in, this is the first thing really fixed, and it looks quite good (sorry for lack of pics, it was very dull). I only hope the sealant works, I used a mastic strip, there was no warning about using it in he cold but it really was not very gooey, more like dry Blutac. I bash the aluminium back a bit, but allow it some space to air, cover the whole length of the old  awning rail with duct tape and the tarpaulin is back on by dusk.

I will have to do something about the damaged centre rail at the very front. Despite drying out, it is too rotten for repair I think. It will have to go, so I have to plan how to support this front section, I think I will span a wood entirely across the 2m width, and sacrifice a bit of height just at the front.

Next time...

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.

End of holiday - progress

Several half days over the Christmas and new year period, and tomorrow back to work.

I must say I thought I would have more done... but its been OK.
I have ripped out a lot of the internal furniture and wood cladding, this has revealed about as much water penetration as I was expecting.

All of the left hand side of the van is stripped back - this is the side that seems worst affected by water. I have pulled off the 3mm ply - but this seems to be bonded to the insulation beneath, and this has made it hard to remove without damaging the foam insulation (I decided to try to keep this intact as it is unaffected by the water, and seems to lend stability). It is especially hard to glet off in the damp areas - see the most damaged bits.

The wood at the top and across the ceiling is quite wet (but not rotten). Not decided whether to replace or treat this.
I also removed the wooden unit over the wheel arch on this side, this was quite simple. However, close to the wheel the water ingress is very bad, this part is not insulated  as the rest, but thick chipboard or something. This is very badly rotted, it basically all crumbled away.

There is a 20mmx20mm wooden rail across the bottom, this is quite rotten, it presumably was attached to the base through a steel rail outside (now missing). There is serious leakage around the skylight, this has caused rot in the wood on the lower edge down to the door area.

My first error
While clearing the ceiling around the skylight, I opened it, and it was clearly weak anyway, and the handle broke clean off. I did not have a suitable glue, this is not really repairable anyway, so I bodged a repair with Sikaflex sealant and duct tape. The vent is 400mm square which is a standard size (as in toilet room), so I will have to invest in replacements sooner rather than later.

Leak Central
After rain, it is clear that this stripping has given freer access of water to the inside (duh...). Obvious that the centre rail down the middle of the roof is leaky, and along the top rail on the left side (only).

So, I take to the roof. Not quite sure how to work on this as it is more than 3 feet from each side. Easy to pop up at the front and back (and I suspect this joint has never been redone since new).

From the sides, it seems a bit too much to lean all the way into the middle. I will have to get 2 ladders and make a temporary platform I think. I can at least now say that the ceiling panels are in good condition, but all joints need resealing. I plan to do this (having googled extensively) with mastic strip and Silkaflex 512 sealant. I an confident the centre rail is fine, but most of the rails on the rest of the van are no good. I think I should practice on an easy to reach part before venturing onto/ over the roof.