What mold kills on wood and drywall

What is the recommended way to destroy mold?

I just find it useful to summarize all of the information I could find on the internet about it and the unanswered questions and hypotheses that have yet to be tested.Please feel free to correct and update my answer or by leaving a comment below (Verified information and test results are more than welcome).This answer is in progress: Many things written here have to be confirmed (cf. (1)), others have to ask questions in the stack chemistry (cf. (2)).

First, our current level of technology is not advanced enough to solve this problem. The solutions suggested below are more of a workaround than anything else. Since mold needs moisture, cellulose (it eats them), and air to survive, the most efficient way to control moisture remains (which is unfortunate for those who can't).

Molds are difficult to eradicate because:

  • It can live deep in things. So it is not enough to just kill the visible mold.

  • It is not enough to kill all of the molds (the visible ones and the deeply rooted ones) as the molds produce countless tiny spores (their "seeds"). A single spore can trigger a whole new mold invasion on its own. The spores are pretty hard to destroy (1) and they also float in the air.

To get rid of the mold invasion, several measures appear to be needed:

  • 1 / killing the visible form,
  • 2 / kill the molds deeply rooted in the wood, wallpaper ...
  • 3 / Prevention of a next invasion: - by making the environment for the growth of the mold harsh - by deactivating / killing the spore

Killing the visible form: it's easy to do with bleach, peroxide ... (see below).

Killing the Ingrained Shapes: This is a different story as you need something to get the product (which kills the shapes) into the wood. You will need to use a "surfactant" like dish soap (there is probably a more effective one) (1).

1 / Prevention of (most?) Further invasions:

- By making the environment harsh for mold to grow: molds appear to be pH sensitive. Some are destroyed by an acidic pH, but others (most) by a very basic pH (above 9).

- By disabling / killing the spores: that's the really hard part.

Raise the pH: It appears that a basic pH can kill and (and possibly deactivate the spores?) The mold. That is why it is used.

borax (Sodium borate, sodium tetraborate or disodium tetraborate) is quite basic and kills / prevents or slows down the growth of mold. (Most, but not all, types of mold require an acidic environment). 1 tablespoon in warm water (approx. 40 ° C - makes it easier to dissolve)

According to many sources, borax was effective and permanent, but some concerns have been raised about its health effects (particularly if ingested or in contact with the eyes). If I got it well, it has often been used for anything and everything without worrying about its potential toxicity (it's also not biodegradable). In the results, it was “classified” as a potential threat by the European Commission (including fertility problem).

Since borax is hard to find (in the EU) I was wondering if a strong base solution could do the job. For example, what about a solution that contains (cheap) dishwashing powder (2)?

"Borax substitute": Sodium sesquicarbonate is much easier to find (in the EU) than borax, but is it really as efficient? And what about its shelf life (unlike borax, it is biodegradable) (2)?


—Concrobium Mold Control: This product also plays a role in pH to remove mold. It contains sodium bicarbonate (baking powder, pH = 9), sodium carbonate (washing soda, pH = 12) and trisodium phosphate (TSP, pH = 12). Is TSP used only to increase pH or for other reasons (2)?

- Sodium Bicarbonate: The pH is lower than Borax's, so it seems less effective (in my case this solution slowed the process down a bit, but not by much). But it is safe.

- Sodium per Carbonate: (2) - Trisodium Phosphate (TSP): (referred to as "borax substitute"). Does it work despite its biodegradability? (2)

- The sealing solution (seems to be the most effective): clean the underlay of the form, wait long enough to dry it, and “glaze” the underlay (e.g. with a transparent base flooring product). The mold will not come back to this, as a thin layer of "plastic" protects its food (cellulose) from it. As for the shape that was sealed under the layer, it is not clear what will happen. What would happen to a shape that is simply made with a thin layer of PU or wax? But it protects against the spores that are the main health problem. (2)?

2 / Kill the form:

  • Bleach: Kill the visible mold (how? (2)), but the chlorine does not penetrate the wood, wallpaper so that the deeply rooted molds are not killed. The water in the bleach penetrates the wood, allowing the inner shapes to grow faster.

  • Hydrogen peroxide: Like bleach, but safer (no toxic gas) By changing the pH: Acid solution (vinegar ...): Can kill the mold that must ever be basic. A base solution (baking soda, borax ...) can kill molds that ever need acid.

  • What works for me (a little): mix some hot water with borax, then add 30-50% bleach and a little washing-up liquid. Remove the shape with a sponge.

3 / killing / deactivating the spore:

Since spores can float in the air, some recommend using chlorine dioxide: it's a gas that kills (deactivates) the spores (of most species). Above a certain concentration, the gas is unstable and explosive, so you won't find it in your supermarket. But it's easy to do ("assuming you can find sodium chloride". I'm still looking for it ...). All you need to do is mix a drop of sodium chlorite with a drop of acid (e.g. citric acid). When the two drops meet, the gas is created. It is best to evacuate the building during the process (they recommend 48 hours). (You can find devices that measure the concentration of this gas on eBay.) Some hospitals use it.

In short, many questions remain unanswered. We're still waiting for THE scientific invention to deal with this (a gene therapy?)

(3) The DIY technique for PU coating is simple: I just missed some PU expansion foam with acetone to make PU a water-like substance that can contain PU coating material (11g / 100ml is also good good for camping equipment, it is not hydrophilic and waterproof, but "breathable"). But watch out for the isocyanate: it can penetrate your skin: latex gloves should probably be fine for 10 minutes, but no more (or use a PP plastic bag as gloves).






spent some time sharing this information and being voted down. Why?

Tom Busby

Not the downvoter, but the time spent responding does not directly correlate with the quality of the response


@ TomBusby I agree. In terms of the devaluation you justified by your comment, I would say this reflects the way the average stack user uses the down button.


@JinSnow, stumbled upon your post a year later. I suspect the rejection was for that reason. Answers should be final solutions. You have a lot of information here, but they mostly duplicate other answers, and much of the supplementary information is phrased as speculative and even adds new questions. You've added some general reading sources at the end, but they're not tied to any specific facts. It might have received a better reception if you had limited it to what you know for sure (quotes) and left out your own unanswered questions and everything speculative.


@ TomBusby "Answers should be definitive solutions", no. Answers should bring the most useful information. In most cases there is no permanent answer, the solutions are constantly evolving. "Not bound by specific facts", well, just "known alternative for getting rid of mold". Some people join the pile to rule and get their views across, others to share information. Better to invest your time suggesting a better answer than degrading / wasting the time of people who invest their time to share.