Damp patch on chimney breast. - Orange mould/fungus.

VoucherMan

I had the bedroom wall re-plastered a few months ago and in the last few weeks a small damp patch has been growing at the top of the chimney breast.

Until I can get someone to check the roof I'll not know the cause but I expect it's either damaged flashing/slates or the result of hygroscopic salts. (thanks Google)

There's a 'living flame' gas fire in the fireplace which I never use as it's hopeless at warming the room but I wondered if it may help dry out the chimney - very little heat seems to come in the room so there must be a lot going up there.

Occasionally I hear raindrops on the casing of the fire so it may be worth getting some sort of cowl fitted.


Any suggestions on cure / prevention would be welcomed, especially as to whether using the gas fire is likely to be beneficial (and if so how often)

I gather I'll have to remove all the affected plaster, but I'd sooner fix the cause first.

Gloomendoom

The damp may be getting in down the chimney. I try to light a fire in my fireplaces at least once a week, even over the summer, in order to keep the damp out.

Gas fires create a lot of water in their exhaust so, unless the chimney is lined, you may make things worse before they get better.

iamcornholio

If this damp is getting in via the roof or defective flashing, then drying the flue with the fire wont make any difference.

Damp along the breast/ceiling junction is more then likely running down the outside face of the breast from defective flashing

A patch further down the breast is more likely damp via the flue

VoucherMan

Got roofer to sort problems. Turns out there was some damage around chimney and a few loose tiles.

Went to clean bedroom wall after roof had been fixed and there was some orange fungus / mould growing on the wall. There seems to be plenty on the web about black growths but I've not been able to identify this orange one.

Any suggestions on what it was likely to have been?

I've scraped it off & cleaned the wall with a bleach solution so it hopefully wont return but had hoped to identify it.