undetected water leak

[rooster63]

I recently found out that water has been leaking into the roof lining of my pvc through small cracks in the sealant around the sky light. It must have been have been doing it for quite a while as an area of plywood used to line the roof has rotted away although there was no visible evidence inside the van. The construction of the ceiling is as follows: A layer of insulation material/wool like used in loft insulation, a layer of plywood and then some sort of plastic and material roof lining. I have broken away as much of the rotten plywood as I can and have pulled out all the sodden insulation material. I have successfully sealed the crack using Captain Tolley's Creaking Crack Sealant (the rain we have had today and Saturday seems to have been kept at bay) and as it has been sunny as well I am confident that all has dried out. The plan is to replace the removed area of insulation using some thinsulate insulation and cut some plywood to fit in the spaces where I have removed the rotten pieces ( a couple of the fitting screws for the inside part of the skylight screws into the wood).

It is virtually impossible to remove the whole roof lining to do a 'proper' job as it would entail dismantling all the high level cupboards and more and I know it will not go back the same!!

Is there anything else I should do? I will monitor the situation for future leaks and if necessary remove the whole skylight and reseal but reluctant to do that yet as already quite a few of the fittings are broken and I think trying to undo rusted screws (the van is 13 years old) could cause more grief.