ᐅ Brown stains above the fireplace

Hello,

After 1.5 years, we have noticed yellowish/grey soot stains forming on the walls and corners near the chimney.

When we moved in, we did not paint with a white paint that includes a nicotine blocker. We now need to address this. Basically, the heat outlet/seating area is on the chimney. Is there possibly a solution, such as a soot filter or something similar?

Thank you

Hello

Yes, particle filters for wood-burning systems are available.

However, it is not clear to me what exactly this is about.
Do you have any pictures of the wall?



Olli

wrobel schrieb:
Hello,

Yes, particulate filters for wood heating systems are available.

However, I’m not exactly sure what this is about.
Do you have any pictures of the wall?



Olli

I will do that and upload them...

Here are the photos ...

You might want to search for black dust or fogging. Not sure if that’s what it is.

The substances involved in the formation of black deposits come from various products brought into living spaces. These products were usually introduced by different people (residents, building managers, contractors). Generally, it cannot be assumed that these individuals acted negligently, as they are often unaware that the products may contribute to the development of black deposits. On the manufacturers' side, there are still few suppliers who label their products for problematic substances—such as plasticizers. Since not every product containing plasticizers is likely to promote the formation of black deposits, most manufacturers see no need to disclose the content of their products, for example, the plasticizer content.

However, there are positive examples: Some well-known paint manufacturers have offered for some time paints clearly labeled as "solvent- and plasticizer-free." The environmental label "Blue Angel" is also an important guide for consumers to make informed product choices. Particularly if one has previously experienced issues with black dust deposits in a home, care should be taken during renovations to use only products low in problematic substances. Although this alone does not guarantee that black deposits will not reoccur (due to the complex formation process), experience shows that the problem usually does not recur when targeted products are chosen for renovation and thorough ventilation is carried out over several weeks after the work is completed.

Is there a health risk?

Based on current knowledge, black dust deposits do not pose an immediate health risk. The concentration of problematic substances—such as semivolatile organic compounds like plasticizers—is only slightly higher in affected homes compared to unaffected ones. These concentrations remain significantly below the threshold of any potential acute health hazard known to date. Nevertheless, for precautionary reasons—and not to mention the "aesthetic" problem of an unsightly living environment—it is advisable to identify the causes and remove the deposits. However, if the deposits contain elevated levels of polycyclic aromatic hydrocarbons (PAHs) or soot (both produced by combustion processes), a health risk may exist.

Damage removal

Before starting to remove the deposits by cleaning or attempting to eliminate them through renovation, it is important to identify the causes of the contamination. It is usually not necessary to eliminate every contributing factor in each case. Often, addressing individual factors is sufficient. For example, when renovating, choosing a paint that is solvent- and plasticizer-free can help. In some cases, adjusting heating habits may also be beneficial.

Repairing structural defects (thermal bridges) helps prevent the deposits from forming preferentially in those areas. Also, reducing the use of candles and oil lamps can alleviate the problem. Removing the deposits often requires intensive wet cleaning using detergents, synthetic cleaners, or similar products. Simply painting over the greasy deposits usually does not work. During cleaning, affected wallpaper, for example, may be so damaged that it has to be completely removed. In some cases, flooring must be removed or more significant structural measures (reducing thermal bridges) undertaken. However, such extensive actions should only be considered if the "simpler" renovation steps (using solvent- and plasticizer-free paints, thorough ventilation after renovation, avoiding soot-producing candles, etc.) have not been successful. To clarify individual cases, site inspections by experts and questionnaire evaluations are carried out, along with chemical analyses in the affected homes. Such analyses are only meaningful if, after site inspection, there is suspicion of a "fogging" phenomenon and the deposits have not been present for a long time. An analysis is also recommended if it is unclear whether the deposits are black dust or soot from combustion processes (or both).

Never again black deposits?

The problem of "black deposits in homes" has not yet been conclusively solved as long as we do not fully understand the specific contributions of

• residents' behavior (ventilation, heating, use of candles, etc.),
• the building's condition, and
• the composition of the products used.

As long as the cause-and-effect processes involved are not clearly identified, only preventive measures can be taken. These include, for example:

• using low-emission products,
• eliminating construction defects, and
• proper heating and ventilation.

Some initial steps have already been taken on the product side to reduce the presence of substances in indoor air that can promote this phenomenon: various paint manufacturers have offered "solvent- and plasticizer-free" products for some time. This approach should in the future be extended to other products intended for indoor use from which these problematic substances can be released.