Damp chimney breast, damp patch, yellow staining, happens when it rains?

The two below pictures show a small amount of yellow ponding on the hearth of the chimney. I was called into this property to find the cause as everybody else was just having a guess. This is actually deliquescent salts from long term burning of fossil fuels. On the day of the survey the humidity was very high and it become deliquescent right in front of me, and this also occurred on another chimney in the house but not to this extent. You can see the sample pot on the hearth that I removed which had extremely high levels of chloride, nitrate and ammonium…..typical of very long term hygroscopic and deliquescent chimney salt issues. If you have issues with a damp chimney in a bedroom, in a loft, or anything to with a damp chimney I can help with mortar samples following BRE DIGEST 245 Laboratory analysis to prove if its rainwater penetrating, or hygroscopic salts. Drop me a message at enquiries@completepreservation.co.uk

With over 15 years of experience in quantitative chimney damp analysis I can get to the bottom of the problem for you 🙂