When building a private house or overhauling an apartment, a very important step is the screed, which is designed to level the surface before the finish coating.
Beacon floor screed
The process of installing a beacon system in preparation for leveling the surface of the floors is quite complex and extremely responsible, requiring a maximum degree of accuracy, as well as a strict sequence of actions.
The level of quality of the future surface, and therefore the operational characteristics and appearance of the planned decorative floor coverings, directly depends on how correctly the beacons are installed under the screed.
What is the role of lighthouses in the construction process?
No matter how hard the general construction work is carried out, it is almost impossible to achieve that the surface of the floor slabs is perfect, and that they themselves have a strictly horizontal arrangement. There is always a slight difference in height. In addition, it is often required to perform a certain level of waterproofing, insulation or installation of heating systems “warm floors”. In any case, the “finishing” surfaces, on which the decorative coatings will be directly covered, become at a level slightly higher than the foundations.
The very procedure of leveling floors using the method of pouring (or filling) screeds requires a separate detailed consideration - there are a lot of different nuances here, from preparing the surface of the base, ending with choosing the type and the required proportion of the solution.
But how can we ensure that the created surfaces are perfectly horizontal? In order to answer this question correctly, you need to better familiarize yourself with the purpose of the lighthouse system.
At its core, the floor screed on the lighthouses is nothing more than a collection of guides that are installed on one, strictly verified level. They serve as a good reference point for a worker who floods the floor, and an indispensable technological device that greatly simplifies this responsible and labor-intensive process.
General principles for the installation of beacons
In order for the installation of beacons for floor screed to be carried out in the highest quality, it is very important to observe the two most important conditions:
- Exact zero-level beating.
- Strict adherence to the required distance between the guides.
Level zero
If you want to give a really high degree of strength to the screed to be filled, in order to extend the service life as much as possible, its thickness in the narrowest sections should be no more than thirty millimeters, since it is such a value that is considered ideal for zero level beating.
Some of the species (for example, dry floor screed on lighthouses) require a much thicker layer - from fifty millimeters.
In corners that visually seem too high, marks are made on the walls at a distance of, say, fifty centimeters from the floor.
Using hydraulic levels or building ruler levels, these marks should be moved around the entire perimeter of the room wall. This process can be greatly simplified and accelerated if there is a high-quality laser level.
From this strictly horizontally drawn line, the distance to the floor surface at each of the sections of the wall of the room should be measured, recording the result. The place where this distance will be minimal should be taken as the highest point on the floor.
At the identified point, make a mark above the floor surface by about thirty millimeters (at the maximum thickness of the screed). From it, as in the first case, a strictly horizontal line should be drawn along the entire perimeter of the wall. This line will be the “zero” base level.
In order to make sure that everything was done correctly, you need to check the floor levels in the center of the room - there are times that it is higher there than against the wall.
A check is made in a number of places with the help of cords stretched along the baseline zero lines. If the level in the center of the room is higher, or if the thickness of the screed is too small, the zero line should be shifted up by the desired distance.
How to plan the direction of the beacons, as well as the distance between them?
As a rule, the line of the lighthouse is laid out along the premises, in the direction of the upcoming screed pouring.
From the wall, the first and second parallel guides to it should be located at a distance of no more than three hundred and a half millimeters from each other, otherwise a wall dip may form on the wall.
The remaining beacons should be distributed evenly so that the distance between two adjacent rails is approximately 255-355 millimeters less than the length of the rule available.
Some of the screed technologies require a fairly frequent placement of the beacon. For example, for falling asleep dry screeds you need about eight rails, the width of which should exceed the width of the room.
After the floor screed on the beacons is done, it is necessary to level the surface.
Varieties of lighthouses
In order for the installation of beacons for screeding, the use of special metal profiles or devices, as well as some improvised materials.
The choice of installation method will mainly depend on the type of screed to be poured or poured.
Metallic profile
As a guide, when lighthouses for floor screed are installed (photo), a metal profile is mainly used.
When installing screeds with a minimum thickness in a small room, a stucco metal profile may well be suitable for this purpose.
Nevertheless, in spite of the so-called "stiffening rib" that he has, he does not have a particularly high level of strength, and with a large volume of pouring mortar, he can not cope with such pressure, as a result of which he begins to deform - spring or bend.
As a very successful alternative, lighthouses for floor screed made of a metal U-shaped profile for drywall are often used. It can be narrow ceiling, with a side shelf height of twenty seven and a half millimeters and a lintel width of twenty eight and a half millimeters, or wide - twenty seven and a half by sixty seven and a half millimeters.
A special advantage of this approach is that thanks to it very convenient guides are created, which are necessary for movement along them rules when filling.
In the process of using a heavy solution, there is always the possibility of folding two profiles into one (with a rectangular section), thereby adding strength to it.
Underfloor heating system
The beacon for screeding the underfloor heating and pouring the mortar itself requires special attention, since the heated surface is subjected to both physical stress and thermal expansion due to heating and cooling.
The thickness of the tie for the heating cable is recommended to be 3-5 cm. If it is less than 3 cm, it can simply “tear” due to thermal expansion. With a layer of more than 5 cm, the cable may not cope with heating, and the temperature on the floor surface will not be able to match the temperature set on the controller. The optimum thickness of the screed on the separation layer is at least 3 cm.