What are lighthouses? These are elements that help align the plane. In this case, we will lead a conversation about the floors. Lights can serve as wooden rails and metal profiles, in addition, they can be made directly from the solution using the rule. I recommend using special T-shaped beacons, they can be purchased in all construction stores. Why? Well, firstly, wooden rails are usually not even and therefore they must be attached to the floor and equal to use the wedges. Ordinary P-shaped profiles are very bulky, so we will use them as rules, and it is quite difficult to make beacons from the solution, let professionals be funny with them.
So, we will need the following materials: gypsum, it is alabaster, directly the T-shaped beacons themselves, a bath for gypsum kneading, a spatula, a rule ready or made from the P-shaped profile and the level of the horizon on the walls.
We mark the floor with a pencil or chalk on grips (in other words, stripes), starting from the most remote wall. The width should be slightly less than the length of your rule, but not more than 250 centimeters. Know that narrow grips will later be easier to fill (or fill up), but it is easier to make a mistake with them.
Now prepare gypsum. Mix it with water a little, literally for one lighthouse, as it quickly sets. We put piles of gypsum where the lighthouse will be. We place a T-shaped profile on top, align it according to the level. We look at the rule by length: we attach the rule (it is a P-shaped profile) to the lighthouse, and look how closely it adjacent, a small click of 1-2 mm per meter is not considered a defect. Align if necessary. We remove the excess gypsum. We perform the same actions with all lighthouses. After the gypsum is hardened, and this will happen quickly, the lighthouses are ready. That is, you have made a finished skeleton or mesh of future floors, by which you can fill in the mixture or fill up with filling up.
By the way, lighthouses on the wall are made in a similar way, and even on the ceiling. Although the ceiling, of course, is better to align with drywall.