Hi,

I had a gas fire installed last year, and the precast flue is getting
too warm, causing the plaster attached to the flue to crack.

Without replacing the fire, are there any options? Like using heatproof
screed (although I've only got about 3mm depth in the plaster) instead
of plaster; replacing the raised ridge tile with a well vented cowl; or
replacing the effected plaster with lime plaster?

Thanks.