When you think of damp, you probably think of wet patches on your walls caused by penetrating damp, or the telltale salty tidemark of rising damp caused by groundwater wicking up from the bottom of the wall. Chimney damp is less well known, so you probably won’t recognise it even when you have it. But it is a reasonably common problem, and one we see quite a lot in London homes. This article provides a quick guide to the signs and symptoms look for, so that you can get timely help from a specialist damp company.
Signs of Chimney Damp
The signs of chimney damp can be similar to the signs of regular damp, except they all occur around your fireplace or chimney. There may be damp patches on the chimney breast or the ceiling above it, or possibly the walls around it. You might also see staining or discolouration in these areas.
Why Do Properties Suffer From Chimney Damp?
Chimney damp will often occur if your chimney is unused and boarded up. Unused chimneys usually aren’t ventilated properly, so moisture can easily get trapped inside with no way out. If your chimney is open at the top but is not in use, rainwater can travel all the way down to the bottom of the chimney stack. If, on the other hand, the top of the chimney is capped, but it isn’t ventilated, moisture can build up on the inside of the chimney stack, a further cause of damp.
Another significant cause of chimney damp is poor maintenance of the chimney stack, or damage caused by improper building work. Where there are any cracks in the mortar of your chimney stack, water can easily enter through them. If you or your neighbours have had building work carried out on your chimney in recent years and you’ve then developed a damp problem, this is the most likely underlying cause. Some examples of modifications leading to chimney damp include installing a wood burner without the correct flue, or the blocking of ventilation.
What Causes Chimney Damp?
When coal or wood is burned in the fireplace, the tars and salts given off by combustion are absorbed by the flue and chimney breast. These salts are hygroscopic, meaning that they can easily absorb moisture from the atmosphere. Under the right circumstances, this moisture will then spread to other parts of the building.
Even if you haven’t used your chimney in a long time, salts can still remain in the flue from years of combustion residue deposited by your home’s previous owners. The older your house is, the more likely it is that this will be the case, particularly in period homes where fireplaces were used for many years before other types of heating were installed.
What to Do About Chimney Damp
If you suspect you have chimney damp, your first step should be to contact a reputable damp company to have your diagnosis confirmed. You’ll then be in a position to begin tackling the problem. If your chimney is completely unused, it will need to be ventilated at high and low levels to prevent any further damp occurring. You’ll also need to be sure that the room below the chimney is adequately ventilated.
In the right hands, the treatment of chimney damp is quick and easy. So call London Damp Company on 0207 127 688 as soon as you think you have this problem. Our damp specialists and technicians will return your home to its usual cosy condition with the minimum of stress and disruption.