Edwardian roof gully hassle

[sparer]

We have a valley between two roofs and a gully that passes through one of the roofs to drain the valley.

Today, during storm Bert, the electrics tripped and water was cascading through the ceiling. It turns out the gully, that passes through the roof, was filled with crap from pigeons that have been nesting in the roof. The gully is made from timber lined with lead and is open at the top which where it overflowed.

I want to stop the pigeons entering the roof because there are water tanks up there. They are getting in either at the valley end of the gully or at the hip end but I'm nervous about putting pigeon spikes in because they might catch rubbish and block the valley or the gully. I thought about putting a lid on the length of the gully so that whilst the pigeons can get into the gulley, they won't be able to get to the roof space so hopefully they won't bother.

I'm sure this isn't a new problem so what is the usual solution?

I've included a diagram to show the roof and gully.

Thanks

 

[catlad]

I've seen them with lead traps that allow water to pass through, a bit like a sieve.

 

[sparer]

I've seen them with lead traps that allow water to pass through, a bit like a sieve.

Do you have an image at all?

 

[ree]

OP,
Short story is if at all possible eliminate this loft space trough arrangement - look for another method for discharging the box(?) gulley. Maybe talk with the neighbour about a common approach?.
My limited experience of your situation (running thro terraced housing lofts, would you believe) is that they are nothing but trouble - collapsing on Christmas day kind of thing.

 

[sparer]

OP,
Short story is if at all possible eliminate this loft space trough arrangement - look for another method for discharging the box(?) gulley. Maybe talk with the neighbour about a common approach?.
My limited experience of your situation (running thro terraced housing lofts, would you believe) is that they are nothing but trouble - collapsing on Christmas day kind of thing.

I did think of putting a 4" pipe in the gully and changing the lead arrangement around the exit from the valley but the building is listed so whatever I do needs to be very inobtrusive. The timber for the box gully is in good nick so I'm not worried about it collapsing.

 

[ree]

OP,
I understand your difficulties - maybe posting a few pics might help?