Leaks

[Hugo]

In certain conditions water is entering the cavity wall of our house and is dripping down on to the lintel and then into our kitchen.  Finding the source of a leak is always difficult but ours is more so because we have a large double glazed conservatory backing on to the kitchen.
Does anyone know of a tradesman who does this type of work?
We believe that the roof and guttering are ok because they have been checked.

[Yorkie]

I can't see it coming down the cavity wall if the roof is OK, as the roof and tiles should bridge that gap.  I would suggest that maybe the wind is blowing the rain under flashing or the join twixt the conservatory and the house.  Alternatively have you any water pipes in the roof space that could be causing the problem?

another possibility is a crack on the outside of the building near the lintel which is allowing the ingress of water.   Can't give you the name of anyone but good luck anyway. 
 

[Hugo]

There are no water pipes in the roof Yorkie so I was thinking that it was the flashing on the conservatory that was at fault.   The leaks only occur when it is raining and the wind is blowing strongly from the South.
As the conservatory is still under warranty I have approached the firm that built it and mentioned the leak and the flashing but they said that the flashing only goes in a short distance and will not penetrate the cavity wall so they discounted that even though they haven't been here to look at it.
Our problem is that I can't get to that area as we have windows above the leak but unfortunately the openings on the window are not above the leak.
I think that I'll approach someone from a local double glazing firm for advice and have been given a name from a friend.