Our house has a colorbond roof and appears to have a water leak during periods of very heavy rain. Based on where the water stain appears on the plaster it appears to be leaking where there is a "valley" join in the roof. Unfortunately it's an area of the house with a vaulted ceiling so access from inside the roof is all but impossible - making it also impossible to confirm exactly where it leaks.
The valley is caused where the ridge of roof above our dining room intersects with a taller section of roof - so I guess you'd say it's a ridge and two valleys all meeting the main roof, like the roof above a dormer window might do so. (Hopefully that makes sense - There is a picture here if it helps: http://i66.tinypic.com/aylwy0.png). I'd describe the roof pitch as "standard" - I think 22.5 or 25 degrees. I can sort of imagine that the rain runs down the main section of roof for a while, meets this valley and just inundates it pouring straight over.
What is the recommended option to stop this water leak?
Do I lift the sheets where they meet the valley and silicone between them and the tin that forms the valley? Is the valley likely to be damaged or not formed correctly? Something I can attempt myself, something I need a roofer to do (S.E. Suburbs Melbourne) or something that I just have to tolerate?
Thanks in advance - Mark