Stone cottage and breached chimney

[Padraig Clarke]

I am renovating a 100 year old stone cottage in Ireland. The property has not been lived in for about 5 years so there was a big condensation/damp problem. After pulling back some of the plasterboard (within an extension connected to the 100 year part) I could see that the base of the old stone wall was very black and wet. Someone local suggested that the chimney flue was breached and that soot and water were now coming through the old stone (pictures attached).

Does anyone have any experience in this and what would be the process to repair the chimney, but also clean up the old stone work?

 

[Padraig Clarke]

 

[theprinceofdarkness]

The smoke from a fire will attack the lime in the mortar, basically dissolving it out. Also the smoke will percolate through some stones. You will get rain down an uncapped flue. Sweep the chimney and get rid of the loose soot and sand (from the mortar).
This "breaching" effect, you will have to get the locals to explain what they mean.
Frank

 

[Doggit]

If the chimney had been breached, then the effect would be more localised. That seems to be across the whole wall, and makes it more suspicious; I wonder if there was a fire in the property at some point. Knock all of the plasterboard off, and then post some more pictures, and of the outside wall.

Where is/was the chimney, and has it been capped.

 

[Padraig Clarke]

There is no cap in the chimney. The chimney would be dead center in that wall. The wood burner is the other side of that wall and it was just full of water.

Sorry if 'breached' is the wrong terminology. If I recall, he reckoned the cause was soot and water coming through the mortar.

 

[vinn]

Padraig, earlier this evening I replied to your other post on here - now you have this similar post in the building form. I would suggest that you ask the mods to join your other post to here so you will get joined up replies.

 

[Doggit]

If the chimney was full of water, then that could explain the dark coloured wall; the soot would have mixed into the water, and then soaked through, but that wouldn't be a breach. There should be a cowel on the chimney to stop the rain coming in, so that's the first thing to do.

 

[Padraig Clarke]

Thanks. Do I need to consider cleaning that stone wall? Could it even clean up? Or as long as i have fixed the chimney issues, I could just re-plasterboard? Any suggestions/advice appreciated?

 

[Doggit]

If it is soot staining, then I doubt if you'd ever be able to clean the wall, as it's right through it. You're going to need to wait till the walls completely dry, then dot and dab the wall with plasterboard should be fine. But having said that, redoing the battens and then using plasterboard with a vapour barrier might be a better way to go.

 

[stuart45]

But having said that, redoing the battens and then using plasterboard with a vapour barrier might be a better way to go.

Might be, here's one with dot and dab where hygroscopic salts went through the dabs.

Untitled

• stuart45
• 11 Sep 2013
• 1

 

[Padraig Clarke]

Hi all. I have moved attention to the opposite side of this wall now where the burner is. The chimney has been swept, capped and lined with a new flue. What I would like some advice on is the plaster/render at the back of the burner. Should I remove the plaster and re-render or leave as-is and paint it? Or should I consider a covering of some sort (metal plate/ surrender with flue hole).

 

[Doggit]

The first problem you have, is that the stove is too close to the rear wall, and you need to check with the stoves instructions to find the distance the stove should be away from it.

I'd be inclined to hack the plaster/render off, and then use a 45 degree bend to bring the flue out of the wall to move the stove further forward. Then fit vermiculite boards and tile the inside of the fireplace using a heat resistant adhesive. The distance to the side looks good enough to only need vermiculite boards on the rear though.