Am I calculating the correct amount of self-leveling compound?

[Bengt Svensson]

Hello!
I'm planning to floor level at home and would prefer to avoid buying too little leveling compound. I'm a tired parent of small children and my head isn't quite in place all the time (doesn't even feel like it's in the same district sometimes). It's a new build with a concrete floor that needs leveling compound. There will be tiles in the hallway and parquet in the bedroom. In other words, it doesn't need to be sloped, just flat. I just took a leveling compound from the internet as an example.

Area to level: 25m2
KDX leveling compound 25 kg consumption: 1.7kg/mm/m2
Estimated thickness: 5mm
Consumption: 25*1.7*5 = about 213 kg
Number of bags: 213 /25= 8.5

Is this really enough, or did I calculate correctly? Some acquaintances leveled their bathroom with a slope and used about 1.3 tons of leveling compound (the bathroom wasn't excessively large). Is it possible to apply an additional layer of leveling compound if I find that 5mm wasn't enough?

Best regards,
//Mort

 

[tveksamt]

Your math is correct. With the numbers you provided above, the weight is approximately 213 kg.
However, I can't assess if 5 mm is sufficient, I don't have that knowledge.

 

[Holmspel]

It is possible to apply more flytspackel if needed. However, you need to use a primer and check the bag for the minimum height.

 

[nino]

The risk of applying a thin layer is that you "copy" the base, merely moving the imperfections up by 5mm. The best approach is to have several buckets so you can mix a lot before spreading out the first layer and have someone mix the remaining. Spread out with a notched trowel and spike roller the surface, that should be fine.

 

[Bengt Svensson]

To provide feedback, it took 28 sacks and it became between 5-10mm thick on the self-leveling compound. It was a bit of a strain, and luckily we rented a larger mixer.