white "beard" in the tile joints in the basement floor

[Erik E]

Hi,

We have recently moved into a stone house from the 1940s and have previously only lived in wooden houses. I have noticed a phenomenon in several places now during the winter.

First, in a damp garage that doesn't dry out completely (will be addressed), a bit on the rendered facade when the weather turned warmer and the facade was "wet," and most recently in the laundry room in the basement on the tiled floor in the joints under a newly installed bathtub.

The phenomenon is that where there has been moisture, there appears a white foam/beard that seems to be a chemical reaction between water and...??? lime??? Is it something I should be concerned about/address, or is it just something that exists in stone houses in general where there is moisture and less than ideal ventilation?

Thanks for the help!
/ Erik

 

[b8q]

Hehe, this must be one of the forum's most common questions. Most likely, it's a salt deposit. Try putting a little in a glass of water, if it dissolves immediately, it's salt. Completely harmless in that case, but an indication that you have a damp basement.

 

[Erik E]

Thank you, I knew I could get good answers here as always!

 

[anaitis]

Hehe, this must be one of the forum's most common questions. It is most likely a salt deposit. Try putting a little in a glass of water, if it dissolves immediately, it's salt. Completely harmless in that case, but an indication that you have a damp basement.

You're thinking of table salt, sodium chloride, but that's often something entirely different than the deposit TS sees.
The most common is some form of kalk. Doesn't dissolve in water, but does in acid. Hydrochloric acid works if you want to test, but also the descaling solution used for coffee makers.
The deposit is completely normal! Its presence indicates that moisture is being transported through the tile joints, just as intended.
If there's an extreme amount of "beard," it may be a sign that it's a bit too humid under the floor.

 

[tjaboo]

Hydrochloric acid works well if you want to test, but also the descaling solution you use for the coffee maker.

Even vinegar and citric acid should work.

 

[vimsan]

Recognize the phenomenon. Probably salt efflorescence in our basement as well. I seem to remember reading somewhere here on the forum that you can scrape off all the white and everything that's loose and then fill the surface with something like housefix.

Can anyone confirm that this is correct?