Roof leak

[counterunknown]

Hello, I was up in my attic and noticed a leak in a few places. i am worried that its got to the stage that it could be a serious problem to fix (as in expensive).
I would appreciate any advice on how serious you think the problem is, and what would be the best next step.
I am thinking of (as a temporary fix) Using some Flexacryl and Flashband on the ridge until I can get someone who knows what they are doing to come along and fix the problem.
On the out side it looks like one of the tiles has lost a bit of the cement grouting and is it this tile which is directly above the leak.
My main question is, do you think I can just get the leak fixed or does it require more serious work to fix the damp boards underneath and replace the waterproof membrane as well.
Also granted you can really tell from the pictures alone, but how much would a repair like this cost (ball park figures welcome).

I have included 5 pictures of the affected areas. There appears to be one bad spot and 3 or 4 other lesser bits.
Also worrying me is the white mold which seems to be growing on some of the boards down at the bottom of the roof (picture included). I was wondering if this is a by-product of the leak and if fixing the leak should resolve this problem as well.

Thanks

RB

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• counterunknown
• 6 Jan 2013
• 1

third leaking spot.

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• counterunknown
• 6 Jan 2013
• 1

second spot leaking

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• counterunknown
• 6 Jan 2013
• 1

Mold at the bottom of the roof (have treated with fungicide)

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• counterunknown
• 6 Jan 2013
• 1

Main damp spot (under neath the ridge tile which is missing grout and is a bit squint)

 

[^woody^]

Its the ridge tiles and the felt which laps over the ridge. The damp lower down may be related or may be another localised problem

Its a waste of time send someone up for a temporary repair (which may or may not work, or be possible), and then up again for a proper repair.

The work content is unknown so no-one can give a cost estimate