Width of box valley gutter

[seema15]

can you please help me with this .

The lenght of box valley gutter is 7.5-8 metres.
The gutter is to be constructed on top of a wall 225 mm (single wall constructed with celcon blocks).
One pitched roof will be be 25 degrees or less (lower ground level)
Other pitched roof has been measured at 20 degrees at one time and 25 degrees at another time ,(higher ground level) so please reply to both.
The difference in height at eves level is 254mm or 10" with currently pitched roofs.
Mine is the lower level roof and can be changed but the other is neighbours which will not be changed.

 

[catlad]

Sounds like a disaster waiting to happen, I would ask your architect for another option.

 

[datarebal]

If I read this correctly then a box gutter can be formed / fabricated to suit but I would use a standard gutter system on the neighbours side to stop his water splashing up against yours. at 225mm you will have the room, but gutter cleaning will be tricky..