The chimney hearth is often a central point in the home and a family gathering point especially in the colder winter months. Unfortunately chimneys are also one of the places most susceptible to damp in the home. If you have noticed musty or damp smells in and around your chimney, you’re not alone. Read on for expert advice on what to do next.
Damp in a chimney may appear downstairs or on the chimney breast in the room upstairs. There may be:
- Tidemarks similar to those seen with rising damp
- Flaking of the paintwork
- Yellow or brown staining where damp patches occur
- Damp spots that tend to worsen when the weather is wet


There are a variety of causes of damp in a chimney such as:
- Moisture becoming trapped when a chimney is sealed – this can happen if a chimney is capped or sealed as the condensation can build up in the void.
- Rain penetrating the brickwork – cracks in pointing of the chimney stack can allow water to enter. Repointing will need to occur before the dampness can be rectified.
- Condensation caused by burning fuel – this can be caused by the release of large quantities of water vapour as some fuels burn.
- Salt contamination of plaster caused by coal being burnt – because of the chemical composition of coal, nitrates, chlorides and sulphates can migrate from the brickwork into plaster and cause damp patches.
So, what is the solution if you find damp on your chimney? The solution will depend on the cause, so it is worth contacting a reputable damp specialist and asking for their advice so you can ensure you are resolving any issues as quickly and cost effectively as possible.
If you are experiencing issues with damp on your chimney and would like the opinion of a qualified Surveyor we will be happy to help:
Tel: 01276 66466
Preservation Treatments provide Damp Proofing, Structural Waterproofing, Timber Treatments, Condensation Solutions and Structural Repairs throughout London, Hampshire, Middlesex, Surrey, Berkshire and Sussex.
Contact us now to discuss our services further or to arrange a survey.