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Damp internal wall patches around chimney

Posted by Pete Lawless, on
I have a chimney breast with Gas Fire correctly fitted with correct flue etc. fully working and recently tested by gas safe plumber. But above fireplace there is a permanent (contained) damp patch on wall, and in bedroom above a much bigger damp area. Externally we have had chimney repointed, but damp patches remain.
Wayne Beattie

Wayne Beattie

hi pete the damp issue could be the lead flashing around chimney and also the bricks could be pourus and drawing damp in so i would coat chimney with johnsons water seal this will stop damp problems.
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thomas beveridge

thomas beveridge

Hi Pete it could be a number of reasons from staining marks where the damp has been to a faulty lead flashing. I recommend you get a rated people damp expert out to give you a free survey. regards tommy
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Gary Finnie

Hi Pete, Sometimes the damp patch can be caused because you require more pointing carried out to the wall at the back of the chimney not just the stack but I assume the trades people who carried out your pointing would have looked at this. If the pointing was carried out recently, you may well still have damp within the walls that has not evaporated yet and still weeping through the mortar or held within the plaster. If this is the case, give it time to dry, clean spores with anti mould spray and repaint and it should go away. Also it could be that the brick or stone (Not pointing) is now very porous and requires a waterproofing treatment to stop the water ingress. If this is not the case and you are still showing signs of water ingress it could be that the chimney cap is either missing or is not doing its job. Worst case senario the problem is within brick work inside the stack which will need opened up and a chemical treatment applied to the face of the brick. Hopefully not the case. Either way you should probably have it inspected Hope this helps. Gary
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