Unique roof top but with condensation problems

[Tom Smithson]

Hi

I have a fairly unique house with a feature or lantern at the top. See pic below. However it is prone to condensation at the top in the winter. I have tried the following but with a small degree of success

Two vane vents in the lantern
A semi sophisticated fish air small blower unit upstairs that draws air in and a sophisticated extractor fan downstairs in the open plan kitchen.

In the next week we are relaying with GRP the lead flat roof that has a small leak to it near the lantern joint.

We intend to try to drill a hole in the metal spire on top of the lantern and spray foam in.

While we have scaffolding is there anything else or product that people could recommend?

The lantern is wooden and is double glazed and in good nic!

Kind regards

Pin

 

[catlad]

Why don't you block it off with a double glazed unit of some description
and stop all the warm moist air entering that space.

 

[The fan man]

Can you confirm what room in the house the lantern is located in?

 

[datarebal]

you need to stop the warm air coming in contact with the colder surfaces in this cupola also circulate the air which i think you have tried
do you know what is under the flat terracotta panel? insulated?