I sleep quite well. I only poured a few m2 yesterday. In one area there was plastic paint on the concrete before (which I removed). I will wait with the rest until I am sure about this.
What do you mean by 90% RH (relative humidity)? Are all basement floors like this? Or can you have dry floors?
What do you mean by 90% RH (relative humidity)? Are all basement floors like this? Or can you have dry floors?
I spoke with Mapei again. According to him, it's okay to use this filler on a basement floor. "The filler compound is water-damage stable, which means it can withstand moisture pressure provided that a dense surface layer that traps moisture in the structure is not applied."
I'm going with it. The joints will be wide. Then there's also quite a bit of area left that won't be filled at all.
I'm going with it. The joints will be wide. Then there's also quite a bit of area left that won't be filled at all.
There are basements with dry floors, absolutely. But that is not the most common. RH means relative humidity. Google the term if you want to know how to calculate with moisture.
But what this is about is that you get a certain amount of water from below all the time, and then you have a certain moisture content in the concrete depending on how covered it is on the top side. Regarding the coverage of ceramics, it becomes very tight, despite the joints. For example, after taking a shower in a regular bathroom, it takes around three months for the moisture behind the tiles to dry up. Ceramics absolutely trap moisture under the tiles, albeit not completely.
That it is water damage stable is not very relevant in this case.
But I don't understand how Mapei can know that you won't exceed 90% RH in your basement. They can't have any idea about that. Have you received this in writing, or are you taking a chance?
Edit: if you want, you can PM me the name of the guy you talked to, and I can call him. I think it sounds like you talked to a salesman and not a technician.
But what this is about is that you get a certain amount of water from below all the time, and then you have a certain moisture content in the concrete depending on how covered it is on the top side. Regarding the coverage of ceramics, it becomes very tight, despite the joints. For example, after taking a shower in a regular bathroom, it takes around three months for the moisture behind the tiles to dry up. Ceramics absolutely trap moisture under the tiles, albeit not completely.
That it is water damage stable is not very relevant in this case.
But I don't understand how Mapei can know that you won't exceed 90% RH in your basement. They can't have any idea about that. Have you received this in writing, or are you taking a chance?
Edit: if you want, you can PM me the name of the guy you talked to, and I can call him. I think it sounds like you talked to a salesman and not a technician.
I have now talked to the guy you also spoke with. He said that in practice this is a filler that can withstand up to 100% RH, but it's not something they publicly claim. They are simply more cautious than other manufacturers in stating what their product can handle, for some reason. But he agreed with me that a tiled floor becomes very dense and there is a risk that the RH rises well above 90%, but he said that the filler can handle it.
So, it sounds like there shouldn't be any problems.
So, it sounds like there shouldn't be any problems.
