Moisture on chimney breast

[Johntheboy]

Hi all,

Apologies if this should be posted in another section but it seems to touch on a few areas so I thought building would be the best to cover all bases...

Earlier in the spring I noticed some spots of what appears to be damp patches on the chimney breast in the bedroom of the house. As a result, I had the chimney capped (with ventilation) and over the hot summer the patches disappeared. However with a little rain over the last week or so, it’s returned.

The full chimney breast remains through the house, but the area where the fire was downstairs has been boxed out around three years ago as we don’t need a fire in there. This is only present in the first floor bedroom and not downstairs, however the walls downstairs are a lighter colour so it may just not show.

The entire roof was replaced around three years ago so I’m not anticipating any issues with the tiles as such. However it is a semi detached house and the property we’re joined into doesn’t appear to have ever had the room replaced.

At this point I’m thinking it could be pointing on the chimney breast, flashing or an issue where our new roof meets the old of next door.

Has anyone had anything similar to this before or any suggestions of what it could be? It doesn’t feel wet to touch but does feel cooler than the rest of the wall.

 

[blup]

The earlier refurbishment may not have remedied damp within the flue serving the bedroom, and capping the chimney may have reduced ventilation. The downstairs chimney will be served by its own flue and may be unaffected though it should have an air vent fitted.

The flashing and pointing should have been addressed when the roof was replaced, only a physical inspection can confirm its condition, although inspecting for damp or wet rot in the timbers around the chimney in the loft might give some clues.

Just some pointers.

Blup

 

[bobasd]

photos of the roof join an stack an ground floor c/breast might help?

so the c/breast in the pic is the continuation of the ground floor c/breast?
the damp signs on the pic are possibly due to salts comin through from the unswept soot in the flue.
the salts attract moisture from the air.

the downstairs fireplace boxin out as you call it should be opened up an the flue swept . after sweepin when you close the opening back up insert a vent so that the flue has through ventilation.
dont vent the upstairs c/breast.

hack off the whole face of the bedroom c/breast back to brick an render with sand an lime render an a remedial skim.

 

[blup]

Is the chimney shared with the adjoining semi and if so do they use their flue/s eg for a wood burning stove?

Blup