At present I have one of those netting things on top of the chimney. When I had my gas fire serviced recently there were a few small twigs which had come down the chimney. What is the best type of cowl to prevent birds trying to build a nest - we have a lot of seagulls here? Thanks.
The smaller birds come in for shelter especially when its raining. They misjudge the gap when attempting to land on the edge and "bonk" their heads on the canopy. They then fall straight down the flue. Next thing you know (assuming the fire isn't lit . . ) they are staggering/fluttering around the room.
Yea I realised after I posted, that it possibly wouldn't be suitable, which is why I added my 2nd post.
A cowl with a solid top, with enough ventilation at the sides, is what Boto needs .... something like the one in your link ta :)