Improvement on mortar for valley/gulley tiles ?

Still ongoing problems with the valley on my roof. I have clambered on and managed to stick some metalised gaffer tape over 2 cracked tiles, and run some along the obvious places where the mortar was cracked. This has improved the situation tremendously ... now when it rains, a small damp patch appears on the wall. When it's not raining, the dehumidifier dries it back quite quickly.
Need to go through the rigmarole of contacting a roofer. (The one I used 2 months ago (took £1,200 pounds from me too) has had two chances to come and quote, but after another week of no show, I've had enough).
Clearly the valley needs to be put straight. The lead flashing was replaced 4 years ago, and looks grand. It's just the mortaring of the tiles that seems to be the issue.
Is there any more modern system cf the ridge tile system I had fitted, where the tiles are held in with plastic clips which are screwed into a batten with a waterproof skirt underneath them ?
Mortar seems to be the worst idea ever IMHO. If anyone wants to reply and say that it's the best thing since sliced bread, as long as it's done properly, then it's still shite as over the past 12 years, I've had 4 roofers mortar the ridge tiles, and it only seems to last 3 years.
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On 10/02/2014 13:56, Jethro_uk wrote:

Same on our roof. Roofer was shit hot with slates and lead but knew SFA about mortar. Pva is the answer IME, whether added to the mortar or applied to the surface. Cheap and easy but they won't use it for some reason. Presumably it shaves a fraction of a percent off their meagre profit margin.
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If the tiles are correctly cut, no water will leak in a valley even if you haven't mortared it yet, unless there's a really strong wind. If they're mortared and it breaks away, then the cracks in the morter can funnel the water under the tiles. However, it still shouldn't come in as the underfelt and gutter should catch it, unless the underfelt has failed, or there isn't any.
IIRC, I used a 3:1 or 4:1 mix when I pointed my valley. It is kind of tricky to do, as the tiles move when you stand on nearby ones, and it's all too easy to destroy the bond as you work on the next tiles. The mortar should be under the edge, so that if the bond does crack, the water is still not directed into the crack.
In my case, the original leak was due to a broken tile higher up, water running down the underfelt, which had rotted off just when it got to the valley, and dropped into the loft. I stripped it all off and fitted a modern underfelt, and the strip which runs under the valley is not even a breathable one, as I wanted that to be well waterproof.
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Andrew Gabriel
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On Mon, 10 Feb 2014 15:35:47 +0000, Andrew Gabriel wrote:

You've convinced me that *anything* is better than mortaring.
Just had a roofer look at it via some photos I took when I was up there. He's suggested a dry valley system (I have googled it) and says he can do the leaking one and the one the other side (which is the same geometry, just not leaking - yet) with new felt, battens and tiles for £1,800 all in.
I'm inclined to take this, as shopping around *may* get a cheaper quote, but I really can't do with the hassle.
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Post the pix up somewhere be interesting to See Jethro...
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