Leaking butterfly/inverted pitch roof

[gravamen]

Hi, I have an inverted pitch or Butterfly roof which is leaking from the centre, into the loft space and down into the bedroom below. Only during heavy sustained rain.

I've just been up with a ladder and run a hose along the central gulley, and I can see that the water isn't draining very well. The central valley has some debris but not enough to stop water flow I wouldn't think.

The downpipe hopper isn't blocked. But five minutes after the hose has been switched off the water is just standing there. Perhaps there isn't enough of a slope?

What would be the solution to a problem like this? Cursing the design of this roof at the moment!

 

[datarebal]

Obviously not enough fall.
But if the seams were intact it still should not leak unless it is holed..

Looks like it is zinc, A hard metal specialist might be able to repair without making a big job out of it.

 

[catlad]

That's funny as I was thinking it was a rubber job!

 

[datarebal]

That's funny as I was thinking it was a rubber job!

Might well be , it did cross my mind but it looks like a soldered joint 5 slates on

 

[noseall]

Obviously not enough fall.

Agree, it looks hopeless. I'm wondering if the lack of fall is coupled with a tired roof (sag) which will compound if the water decides to pool at the weak spot.

 

[datarebal]

Yes of course,
In an ideal world one would strip it out and re build it with a good amount of fall.
How deep are people's pockets just now ?

 

[noseall]

How deep are people's pockets just now ?

About as deep as that water ponding in the valley.

 

[datarebal]

Could put a velux in I guess, and some koi

 

[gravamen]

Yes of course,
In an ideal world one would strip it out and re build it with a good amount of fall.
How deep are people's pockets just now ?

I had been thinking about something like that. Any patch job feels like I'm just kicking the can down the road, in terms of that sagging central bit of the roof. What would something like that set me back do you think? (london prices sadly, though not earning london or any wages at the mo). And what would it entail? Have loft access from below on both sides of the roof.
Thanks for the advice. And the humour!