Hi

During cold weather and after a couple of days after heavy rain has fallen, the chimney breast in my converted loft bedroom shows discolouration. This only happens during the winter months, not during the warmer months. I have been advised that the roof is in good order, roofers have checked the pots (which have ventilated caps), the flashing, and the tiles. Some roofers have advised me to have the whole chimney stack taken down. I have had the chimney swept just in case of blockages. The fireplace is not in use.

The last guy I had round, said immediately that it was condensation. Does that sound possible, and if so, why does it only happen after rain? What can I do to remedy the situation?

Look forward to hearing from you

If it happens after rain then perhaps water is getting in somewhere else, evaporates naturally and then condenses on the chimney because that's the coldest thing?

I have been opening my windows in the morning, and when I am not in the room, to let in some air, and so far, there have been no further problems

Hi, this is a simple fix, basically the reason for the damp showing in the winter around the fireplace is due to hygroscopic salts, when you burn fossil fuels the fuels release hygroscopic salts, these salts contaminate the plaster, the salts will then draw any moisture in the rooms atmosphere the same way as your salt shaker does if left in the kitchen or anywhere with a humid atmosphere,

What you need to do is remove the plaster and replaster with a gypsum free plaster this will solve your problem