ᐅ Water damage in basement at insulation layer (cork granulate)

Hello,

we have water damage in the basement – the seal of a sewer pipe had a leak, and over months, if not years, small drops kept getting into the insulation layer :-(.

The insulation is loose cork granules in the floor; it’s a black material. The previous owner referred to it as “fire cork.”

A drying service has already been here and could theoretically dry the insulation layer – but they declined, citing that since it is an organic material, they cannot be sure whether it has mold or other germs. They recommended that I break up the basement floor including the screed and remove the material.

That would be a major effort and therefore quite expensive :-(. When I search online for cork, I often find that it is resistant to mold.

Does anyone here have experience, especially with cork or building drying? How should I evaluate the company’s statement?

Thanks and best regards,
steven11

I can only say that cork is basically completely resistant to mold and rot. I’m not familiar with "brand cork" – maybe it’s mixed with other materials?
I would only dry pure cork – just my amateur opinion. If the cork is mixed with other materials, it’s safer to remove it.

P.S. Removing screed is one of the easiest jobs in the house. Strong arms and a sledgehammer or a small construction debris container are enough, plus a Saturday with one or two friends to help.

We have dealt with water damage here several times. In the house we currently (still) live in together with my parents, this is already the third water damage incident in the basement (each time for a different reason). The latest one was likely caused by heavy rain; all the neighbors had water in their basements, but for us, signs only appeared after some time in the form of efflorescence on the walls.

The entire floor structure was disinfected by the drying company and dried for 4 weeks. Now we are moving on to the renovation, and we are currently waiting for the quote.

A few years ago, my sister also had water damage in the ground floor of her house due to a leak at a pipe connector. The entire ground floor had to be stripped back to the shell: screed including underfloor heating, plaster on the walls up to about one meter (3 feet) high—everything removed. It was a huge effort, especially since they had lived there for just over a year and everything was still new.

In both cases, the same company handled the work.

I can’t say anything about the cork, but if in doubt, I would follow the company’s advice.