If you decided to reconstruct your old parquet flooring and also to throw out the scoria that is often under the wood flooring in the apartment buildings then you were for sure confronted with a question what would be a good replacement for the scoria. There is definitely not many choices but you have to decide if you will choose a dry process or if you will prefer a wet process.
Replacement of the scoria with dry wood ecological granulate CEMWOOD
You can replace old scoria on your floor very fast with wood granulate with mineral coating CEMWOOD. You can made ground from it to height of 18cm and a huge advantage with this material is speed. More or less if you decide to reconstruct your floor in an apartment with exchanging of scoria, you can exchange it during the first day of reconstruction and install the flooring on second day. You can read more about this wood granulate CEMWOOD at www.cemwood.de where you will find all necessary information.
A short video about how you can use the new construction material EcoPearls, or CEMWOOD (they are the exact same materials)
Following video below is from my first job where I came across with this granulate personally and I have to say that it really is an exceptional material:
Replacement of scoria with a wood grill and OSB plank
With the dry process you replace the scoria with a wood grill. You have to calculate the height of the grill so you will get it to the same height that when you will put the flooring on it will be the same height as the next room or hallway. I suggest you to make the grill with spaces around 30 cm wide. So the wood joists won’t be more than 30cm from each other. I also suggest you to fix the grill properly to the surface. Never just put it on the surface loosely. Wood likes to work and such unfixed grill can make a lot of trouble in the future by making unwanted sounds.
On the grill we put an underlayment similar as we used with laminate flooring and then we will install the OSB planks with groove and tongue joint and thickness 25mm. OSB planks need to be fixed to the foundation with screws. I suggest you to glue the groove and tongue joint with elastic glue in a package similar to the silicone packaging that can be pushed out with a pistol used for that. But the pistol for these types of glue is a bit bigger.
On finished floor from OSB planks we can then install either laminate, wood floor or glue massive wood parquet on the whole surface.
Naturally the composition of the floor can be different when you use dry method of replacing scoria. For example you can also install not only OSB planks on the wood grill but also floor „cetris“ (material from concrete and wood splinters) planks or other support underlayment materials for flooring.
Scoria replacement with lightweight fast-drying coating
When you use wet process of replacing scoria in the apartments I suggest you to replace it with lightweight coating. That is because if everybody would use the classic coating, which is heavy, then I don’t know if the apartment building could take such a burden.
If you still want to replace scoria with the classic concrete coating then contact some structural designer if your floors allow such burden. Another disadvantage of the classic coating is apart from its heavy weight also its long period of drying. Concrete coating of thickness 7 cm dries for about a month until it is possible to install flooring on it. Lightweight coating, also called sometimes as pearlite coating dries much faster because in its volume are (in layman’s terms) polystyrene balls that makes is also lighter. On lightweight coating you can install laminate or wood flooring right away. If you want to glue wood parquet of thickness 22 mm or a vinyl flooring on it then you have to put on epoxy coating first (at least 1 cm thick), which I would personally combine with glass fiber. Epoxy coating make the surface of lightweight concrete coating tougher and surface prepared like this is ready for gluing of flooring.
I personally like the wet process of replacing of scoria, even if this one is more demanding on time. Because when your apartment floods it can often happen that your dry wood flooring and grill will swell up, get mold and you can just throw it away. But lightweight concrete coating with epoxy coating on it can be just left to dry and you can install on it old saved flooring or new one again. Wood flooring can start to make sounds like cracking. This will never happen with wet process of replacing scoria.
Author: Soska Milan