Valley Replacement

30 Dec 2018
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United Kingdom

We've got a roof that is leaking in heavy rain, the property is a mid terrace from 1900. I believe it is leaking due to the valley as the tiles look okay to me. I think the leak comes in close to where the bottom of the valley and then runs inside the ceiling down to the corner where it drips out of a whole someone else made in the ceiling. I'm guessing this is not the first time it has leaked.

We have had a roofer over that says we need to replace both the valley and the flashing where the lower roof joins the wall. They are also suggesting the flashing round the chimney needs replacing.

Do people think this is what needs doing to fix the issue and what sort of cost would they expect?

I have attached recent pictures of the valley and the flashing and a overall picture of the roof from 2018.


overall-roof-2018.jpg TopOfValley.png BottomOfValley.png in_rain.jpg
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A couple of grand with a scaffold.

However, with todays shortages, lack of tradespeople, reluctance to take on small jobs, folk may even charge double that.
Is it me, or does the ridge where it meets the main roof look wrong? (2nd photo) Seems like there is a cut ridge tile missing up there. Also, having all that moss in the valley doesn't help water flow much, either
Thanks for the replies.

I am wondering if a lot of the problem is just that in heavy rain the water is backing up in the valley and overflowing into the roof. Should the roofing felt protect against this (ie. there is a hole in it) or is this a normal issue if the valley overflows?

As for the missing tile, looking at all my neighbors roof they all seem to have the same gap there. I guess it is the design.
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I had a similar problem. Water was pouring through my hall ceiling (single storey). To cut the story short it is, I sincerely hope, caused by accumulation of moss in an overlapping tile valley between two runs of adjacent Marley modern concrete tiled low pitch roofs. The moss hinders the water running down the valley to the extent that it overflows the valley sides. Below are two pictures: one before today's moss scraping, and the other afterwards. I used a rodding set with a hinged 'D' shaped scraper and dragged the bulk of the moss down the valley and disposed of it. Removing all of it requires a roof climb and that I am not doing It rained in biblical volumes yesterday afternoon and I suspect it was just sufficient to overflow the valley because it slowed to a stop fairly quickly thereafter.

Where it's was not done very well in the first place.replaceing the top cut tile on the left side might be a good idea , it's slipped out of place and appears no head lap.
Ingress could be running down the underlay to the bottom ..

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