I have a 1900 3 story building.
The chimney stack, serving 3 flues, was lowered 23 years ago as it was disused and leaning. This was done on the advice of a surveyor.
See photo attached. The chimney breast concerned is behind the single story extension and shows the chimney stack still in position. The whole stack was removed in September 2013.
The 2 of the 3 fireplaces served were blocked up over 20 years ago. The remaining one has been left open.
No air bricks were put in the flues at this point or subsequently.
The remainder of the chimney stack was taken down below roof level in September 2013. No one thought of putting air-bricks in!
The flues now open into the loft space and on the inside the roof.
I have had an increasing problem with damp in the top bedroom at ceiling level over these 3 chimney flues dating back 20 years. Up to September 2013 the flues were vented out through the chimney stacks though 2 of the 3 flues had no ventilation coming from the old fireplaces as these had been blocked up.
Many roofers and qualified people have looked at the damp over the years, and no one has suggested that it might be the chimney flues causing the problem. The problem was thought to be a leak in the roof, possibly the lead flashing around the remainder of the chimney breast.
I have had extensive work done on the roof in September 2013 and there is no damp coming in from the roof now.
It is possible that damp had been coming in through the roof, perhaps caused by faulty lead flashing around the chimney or defective pointing and that I am now left with legacy of poorly vented chimney flues. Nothing definitive was found at the time to explain the damp.
I have bought a damp meter and have recorded very high levels on the both sides of the interior chimney breasts (Top of the flues and the room side in the bedroom). I conclude that the damp comes now from condensation at the top of the chimney flues.
I plan to put vents internally in all the disused fire places. I understand that the flues will need air-bricks inserted on the exterior wall.
How many of these should there be,
what size and
where should they be located in the flues,
do I need more than 1 in each flue?
Any other suggestions - I am getting desperate.
Regards
Michael0305
The chimney stack, serving 3 flues, was lowered 23 years ago as it was disused and leaning. This was done on the advice of a surveyor.
See photo attached. The chimney breast concerned is behind the single story extension and shows the chimney stack still in position. The whole stack was removed in September 2013.
The 2 of the 3 fireplaces served were blocked up over 20 years ago. The remaining one has been left open.
No air bricks were put in the flues at this point or subsequently.
The remainder of the chimney stack was taken down below roof level in September 2013. No one thought of putting air-bricks in!
The flues now open into the loft space and on the inside the roof.
I have had an increasing problem with damp in the top bedroom at ceiling level over these 3 chimney flues dating back 20 years. Up to September 2013 the flues were vented out through the chimney stacks though 2 of the 3 flues had no ventilation coming from the old fireplaces as these had been blocked up.
Many roofers and qualified people have looked at the damp over the years, and no one has suggested that it might be the chimney flues causing the problem. The problem was thought to be a leak in the roof, possibly the lead flashing around the remainder of the chimney breast.
I have had extensive work done on the roof in September 2013 and there is no damp coming in from the roof now.
It is possible that damp had been coming in through the roof, perhaps caused by faulty lead flashing around the chimney or defective pointing and that I am now left with legacy of poorly vented chimney flues. Nothing definitive was found at the time to explain the damp.
I have bought a damp meter and have recorded very high levels on the both sides of the interior chimney breasts (Top of the flues and the room side in the bedroom). I conclude that the damp comes now from condensation at the top of the chimney flues.
I plan to put vents internally in all the disused fire places. I understand that the flues will need air-bricks inserted on the exterior wall.
How many of these should there be,
what size and
where should they be located in the flues,
do I need more than 1 in each flue?
Any other suggestions - I am getting desperate.
Regards
Michael0305