I have noticed several large dark patches showing through my cream coloured painted walls. These look rather like someone with grubby hands has been touching the walls. Photo attached. Is this mould, or the beginning of mould? How serious does it look (the patches are quite large-sometimes 1 or 2 sq meters) ? Is it something I could deal with straightforwardly by myself? As is probably clear, I’m a complete novice in this area. Any advice and comments on what you think it is would be greatly appreciated. Also any advice on what could be used to clear it.
Possible mould-question from DIY novice.
- Thread starter Jim H
- Start date
I have similar issues with my home, I'm also not an "expert", however, what you need to ascertain is whether or not this is on an outside wall (mould can form as a result of condensation, condensation results as a result of warm air (inside) hitting a cold surface (e.g. a wall to the outside, that may have some form of bridging in the cavity, or just insufficient sealing on the outer skin), also is this in a bathroom, kitchen, where condensation will occur? Kitchens/bathrooms should have an air vent (a legal building regs. requirement now) or extractor fan to expel any condensation. I suspect condensation as this is localised, from your photo, in the middle of the wall. Rising damp will start from the bottom, then up, as will the mould. Best thing to do is do a search online for "Damp Sam", or "Skill Builder" (search for his stuff on damp), and trawl through some of their videos. Skill builder has an excellent range of videos on damp. Careful though, not everyone agrees with their views, of course! and they don't always agree with each other, which makes it a bit more entertaining! Just be open minded, and make your own opinion after doing some simple research.
Thanks for your helpful reply. I think you are right that this is probably condensation as there is nothing which starts from the bottom. Does this mean that using something like a dehumidifier and keeping windows open will sort the problem or do I need to take further action?