How to make a screed?
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Despite the fact that the screed is an intermediate stage in the process of formation of a quality floor, it is nonetheless a very important element. Not everyone knows how to make a screed, and in fact it should be carried out according to certain technologies, depending on the design. Consider the process of preparing the floor and laying screed on the example of an ordinary sand-cement coating.
How to cook the surface under the screed
equal distance from each other, and pull between each pair of cord (it should not hang).
- A suitable temperature in the apartment for work on pouring the floor screed is 10 - 25? С. The temperature may be lower (up to 5? C), but not higher. Through the room should not, and the windows and the door must be closed.
- Debris should be removed from the floor and thoroughly vacuumed to free the surface from dust and loose concrete. The coating is well primed and sealed up the gap with special fillers. If it is necessary to make a warm floor, then you need to lay down a warming or waterproofing layer immediately.To protect the coating from excessive moisture will help plastic film, laid over the entire surface of the floor up to the walls (edges zaginayut).
- An important step is to determine the level of the screed. The success of further work will depend on this action, and the amount of material, etc., will be calculated. To properly mark the top of the coupler help the hydraulic level and chop cord. Most often, the thickness of the cement-sand coating varies in the range of 3-5 cm. However, in cases where the apartment is severely damaged or a multi-layer screed will be laid out, the coating thickness may be 10-12 cm.
- Drawing level: take a mark above the floor. It is formed by applying a horizontal serif on the wall. Transfer the mark, by means of a level, to another wall, continuing to do this until the marks appear on all walls. Combine the marks and form the so-called "zero" level, from which all subsequent measurements will emanate.
- From the level mark "zero" carry out a number of measurements to the floor. In the event that the floor is initially uneven, then the minimum and maximum distance from the zero level will be detected.From these data determine the arithmetic average. Such calculations allow to calculate the required thickness of the screed. After all, its value is greatly influenced by what kind of coating will be put on top (tile, linoleum, parquet, etc.). To make the same level of the floor throughout the apartment, the label is transferred to all walls. On two parallel walls in the existing marks twist two screws at the same distance from each other, and stretch the cord between each pair (it should not hang).
How to make a tie
- Installing guides "beacons" is a decisive action in the matter of how to make a floor screed. To place them, lighthouse strips, ceiling metal profiles or boards are used. Profiles "sow" on a solution of cement and sand, similar to that of which will be made screed. Sometimes the lighthouses are screwed to the base with screws to the desired level. Note: the beacons should not move and be stable in the process of laying.
- When the screed is done with reinforcement, then on the polyethylene film, pre-laid on the base, pour the fine clay in one layer. Over it lay the grid for reinforcement.And then on the grid mounted guide beacons. After a few hours (or better every other day), the thick cement-sand mixture will solidify firmly, firmly fastening the beacons to the grid along the entire length. This will allow you to properly make a floor screed by applying the prepared solution.
- When it is not possible to use a professional portable concrete mixer, you can restrict yourself to any capacious tank and electric drill (with a “mixer” attachment). It is important to control the consistency of the solution, so that it is too thick or liquid, and better like a thick dough. Such a solution is suitable for use no more than 1.5 hours from the date of manufacture. Therefore, the calculation of the amount of the necessary mixture is strictly taking into account the size of the area that they intend to do.
- The calculation is as follows: take sand and cement in the ratio of 3: 1. Approximately, for a screed, which is 4 cm thick with a room area of 13 sq. M. It takes about 7 bags of cement. Knead the slurry of the solution directly on the floor (can be in the pelvis), where it is better to spread a metal sheet. The hill is formed when the sand is poured out on the basis of a bag (about 50 kg), on top of which 1/3 of the contents of the bag of cement are sprinkled and mixed with a shovel in a dry form.This can be done again or two, depending on how much solution is needed.
- Now water is poured into the “crater” of the resulting dry mix. It is necessary to wait for readiness for about 15 minutes, add water again and complete the mixing of the solution.
- Now comes the painstaking, but not complicated process of laying and leveling. First the mixture is poured onto the strip between the first beacon and the wall and equated using the rule (tool). In the resulting pits lay out another solution and re-use the rule. This is done until a perfectly flat surface is reached with a screed layer of the required thickness.
- Advice: in order to prevent air gaps in the newly laid solution, it should be poked with a metal needle or rolled in a problem area with a needle roller.
- Voids are gradually filled between the lighthouses to their top, constantly leveling the base layers. It is better if the work in the same room will take place no more than one day, unless the room will specifically make floors with different levels, or floors over which a different floor covering will lie.
- Until the final setting of the screed, it is periodically sprinkled with water to avoid the occurrence of cracks. Lighthouses withdraw on the second day after laying. Nether close up solution. The drying period of the screed is 2-4 weeks.