Chimney problems!

[Jules03]

Hi

We have an old farmhouse which was built roughly 1860.

We have 2 chimneys on the main roof. One has 2 flues in (kitchen and upstairs bedroom) and the other has 2 flues in (reception room and another upstairs bedroom).

We've had a couple of the bedrooms replastered as we've dry lined the rooms as we're currently renovating the house. In one of the bedrooms, every wall has dried apart from the wall on the chimney breast. There is a small damp patch measuring about 2foot by 2 foot. This skimming was done 6 weeks ago and it hasn't really lightened.

Due to this, we have now starting thinking about we have a damp problem in the chimney and after hours of reading on here, I think we have a lack of ventilation!

We had a new roof put on last year and had chimney caps put on the 3 flues we don't use (we only use the fire in the kitchen). The caps we had put on were the C caps and they have no ventilation in. Nor is the chimney ventilated at the bottom.

Do you think this could be our problem?

 

[dann09]

Has the chimney breast in question been dry lined?
Is this c/breast on an outside wall?

C caps have built-in ventilation, and only go on chimney stack terminals ie. chimney pots.

Did you have all the flues swept and smoke tested?

What condition were the stacks and flaunching in?

 

[Jules03]

Thanks for your reply.

No, the chimney breast hasn't been dry lined and yes, it is an outside wall.

We've been in touch with the chimney man who put the caps on the pots for us and he used Colt caps on them which are ventilated.

We had the stacks repointed about 18 months ago and the flaunching was also done at the same time.

I've tried to attach a photo of the said damp mark. Hope it works!!!

We had a bit of rain fall last night and the damp mark has darkened some what. Not much but a little.

We plan on putting vents into the rooms from the chimney as we don't have no vents at the bottom of the chimney.

 

[dann09]

1. photo didn't work.

2. Was the flue swept and smoke tested prior to any work?

3. Immediate darkening after rain suggests that moisture is penetrating into the flue. Have you physically seen the condition of the c/stack and flaunching?

4. The two possibilities are probably, moisture penetrating into the flue, or lack of ventilation and soot build-up creating a chemical condition called "sulpherisation" which attracts moisture to your c/breast plaster.
Or both the above together.

5. The 1860 chimney breast back wall is probably only one brick thick, and if not well pointed on the outside it will allow moisture into the flue.

6. Hacking off the plaster from the front face of the c/breast and then rendering up, as per DPC work, will be good for a few years. Perhaps.

 

[Jules03]

Hi

Thanks again for your reply.

We have physically seen the flaunching and stack and all is fine. The repointing and flaunching was re-done about a year ago.

We had a smoke test done as well and everything was fine there.

The photo has gone onto my profile I think.

One thing we have thought about is that the flue that the damp patch is on has a liner in and is filled with vermiculite. This was done last year and the flue is used for our kitchen burner. We were advised to put vermiculite down the side of the liner but are now thinking this wasn't a good idea.

With the nice weather, we have noticed the damp patch fades alot during the day but overnight, even when there is no rain, the patch darkens alot.

We are really at a loose end with this and 3 months in from it being skimmed, we can't do anything with this room.

 

[dann09]

1. no pics available.

2. I'm a bit confused as to what you have?

3. The problem c/breast has one flue that has a one-piece, flexible liner that has been insulated with vermiculite?
Was this flue swept and smoke tested before any liner installation?
There is another flue next to it - is this other flue swept and vented at top and bottom?

4. Was the "damp" patch noticable before the liner installation?

5. What kind of kitchen burner are you talking about?

6. What kind of plastering work - if any - was performed on the c/breast when the b/room was dry-lined?

 

[Jules03]

Sorry, I've just re-read it all and it's not very clear is it!

Right, the chimney is on the gable end. It has 2 chimney pots on. One flue serves the kitchen and the other flue serves the bedroom which is above the kitchen. The bedroom fire is not used and hasn't been for many years. In the kitchen we have a Woodwarm multifuel burner which was put in last year. The chimney was swept and smoke tested prior to installation. We have a steel flue liner up that flue which is surrounded with vermiculite. Both flues have been smoke tested and swept and everything was fine.

I have tried to put a photo on again of the damp patch.

The damp patch is in the bedroom and from what we can see, it is somewhere inbetween both flues. This damp patch has appeared from nowhere and has never been visible before. We have had no wallpaper on that wall for 2 years and there has never been any damp patches.

Therefore, the damp patch must be through something we have done.

We did have chimney caps on the pots but removed them last week as we thought ventilation was a problem and wanted air to circulate around the chimneys abit better. It hasn't made a difference to the damp patch though.

We've had the bedroom skimmed (very dodgy plasterer unfortunately who we won't be using again). He has just used a normal skim on the whole room. There was the original plaster underneath and it was all sound so the room has just been skimmed.

I hope that makes it all abit clearer and appreciate your help.

Thanks

 

[dann09]

Thank you for the reply and the pic.

1. Can you go in the loft area above the stain, and examine for any roof leaks?
Also inspect the loft c/breast brickwork.

2. Can you indicate on the pic where you think the lower and the upper flue run - roughly trace their paths?

3. Can you take a pic up the flue from the bed room fire opening?

4. The C terminals should be left in place - properly fitted, they will provide adequate ventilation. Perhaps post a pic of the "c cap" and we'll see if we are talking about the same device.

5. Do not go putting vents into the chimney breast in question, none at all - the b/r flue has a fire opening and the kit flue has a liner and insulation.

6. In the kitchen would you say that there is adequate make-up air for the burner?

 

[Jules03]

http://www.chimney-cowl.co.uk/shop/Top-Lid-3.html

That's the cap that was on the pots that we removed.

I'll get back to all the other points asap.

Thanks again - much appreciated.