How long do different types of floor screed dry?

Laying the floor is one of the most important stages of the renovation. In order for the floor to be of high quality and durable, it must be laid on a well-dried screed. Therefore, you should understand in detail the question of how long different types of floor screeds dry..

How to understand that the screed is ready?

The screed is the base for the floor. Depending on the different species, it dries for about 27-28 days. After that, they start laying the flooring. Since the prescribed drying time is not always the same as indicated by the manufacturer, you need to make sure that it is ready. This question is especially relevant if a concrete screed is made in an apartment when the heating season has not yet begun.

If you install a moisture-proof floor covering on top of a not dried base, the remaining moisture will create conditions for the formation of mildew and mildew. Concrete under its influence will begin to collapse, thermal insulation will be broken. In the future, the finishing flooring will also suffer..

To determine the readiness of the screed, you can use two methods:

  • The answer may be given by visual inspection. The screed must be uniform, with a uniform color and structure over the entire surface. There should be no cracks on it.
  • You can use a large size plastic wrap and attach it to the screed using duct tape. After a day, the film must be removed and inspected. If there are no traces of fogging on it, you can continue to work on the flooring..

Drying of different types

You can walk on the floor within a couple of days after pouring. This does not mean that the base is ready for further installation. The screed dries for a long time. This process may take more or less time depending on the season, indoor humidity.

The number of layers and the thickness of the fill are important factors. Each additional centimeter of coating extends the drying time by at least 3 – 4 days. What matters is the type of finishing flooring you will be using, as well as the type of screed itself. It often depends on its composition how long the poured solution hardens..

From sand concrete

Sand concrete is a popular material used in renovations. It is a mixture of concrete, cement and sand. An especially strong and strong base is obtained from it. When laying, it must be carefully compacted in order to subsequently avoid the appearance of air bubbles..

The cement-sand screed is quite heavy, it is the easiest to manufacture. You can make this mixture yourself. However, in order not to be mistaken with the proportions and quality of sand, it is better to purchase ready-made mixtures that are sold in hardware stores. Of a fairly wide selection, the most popular and optimal will be the sand concrete mixture M 300. It owes its demand to the strength and durability of the coating.

1 cm of sand concrete screed dries for about 7 days. The recommended layer is 3-4 centimeters. It is easy to calculate that it will take 28 days to completely dry..

Such a long period can be considered a disadvantage, but the M 300 screed has undeniable advantages:

  • it almost does not shrink;
  • she is not afraid of a temperature drop;
  • it is fireproof and moisture resistant.

To speed up the drying time of the base, manufacturers often add fillers to the mixture, which help to speed up drying..

10 cm

In many situations, a thick layer of screed is required. For a 10 cm layer, a wet screed is often used. It is versatile and suitable for laying on various types of floors (even on the ground). Any finishing materials can be laid on it. It is easy to install, the procedure can be done by hand, which significantly saves money spent on repairs. Such a screed evens the floor level in different rooms, it is strong and durable.

However, a thick layer of screed has a long drying time. Usually it is more than a week by 1 cm: for each additional centimeter over 4 cm thick, it will take twice as long (for a 10 cm thick screed, you need to wait at least 16 weeks to dry).

If you intend to install ceramic tiles, the remaining moisture can be disregarded. If you want to lay parquet, it can take six months. For a screed with a thickness of 10 cm, there is only one way that does not take time to dry – a dry screed. It is based on a hollow wooden frame filled with expanded clay. A covering of plywood sheets is made on top of it or chipboard is used..

Under the tiles

The readiness of the screed under the tiles depends on its type. More often the tiles are laid on a cement base. You can walk on the cement the very next day. You can start laying tiles on such a base the next day, since the cement quickly loses moisture. While finishing work is being carried out, the screed will dry completely. It is important to comply with the condition: the installation of furniture can be carried out no earlier than 10 days after the cladding. However, professionals do not advise to rush, explaining that it is necessary to let the cement dry well..

If you are going to lay tiles on a sand concrete screed, use the usual method of calculating drying time (1cm = 1 week).

The standard approach requires a 4cm tie. Therefore, you have to wait 28 days. When making such a base, it is important to wait until it dries completely, otherwise the surface under the tiles will not be even. Do not accelerate the drying process by drafts; at high ambient temperatures, it is recommended to periodically wet the surface. Failure to comply with these conditions will lead to cracks on the screed..

5 cm

The 5cm thick screed can be made from different materials, which is why the drying time varies. For example, sand-cement or concrete will take 6 weeks. Recently, gypsum bases for laying flooring have become popular. They are durable, non-crumbling and ideal for dry environments. Their seizure occurs within a few hours..

The gypsum base for the floor is ready in a week if its thickness is 4 cm. The time is calculated as follows: for 1 cm of layer, it takes 42 hours to dry. For each additional layer 1 cm thick, you need to add 90 hours. Therefore, a 5 cm layer will dry within 13 days..

If the screed is made in a semi-dry way, the drying time is significantly reduced. You can step on it after 12 hours after installation..

Three to four days of drying is enough for the subsequent laying of linoleum or tiles. If you need to lay a parquet board, it will take a week.

Semi-dry

To carry out repairs in a shorter time, use a semi-dry screed. Drying time is 4 to 7 days. This is achieved by adding special substances called fillers to the cement slurry. Cement mortar is filled with expanded clay, fiberglass, basalt, expanded polystyrene granules. They perfectly absorb water from the solution, reducing its amount by almost half..

Semi-dry screed has its advantages:

  • There is less free water in it, which must evaporate, so voids and pores are not formed in the structure. The screed turns out to be denser and stronger.
  • Since there are few pores in it, which shrink when the cement hardens, it practically does not shrink..
  • You can walk on it in 10-12 hours.
  • It does not create a high level of humidity, so some finishing work can be started in the room..

Semi-dry screed spreads worse, especially in the corners. You need to add plasticizers to it. Due to rapid drying, a too thin layer of it will not have time to adhere to the base, too thick will be heavy. When using a dry screed, special technologies must be used to obtain a high-quality coating..

Under the laminate

Laying laminate flooring requires an almost perfectly flat surface so that the panels do not creak or sag..

Therefore, the following types of screeds are used:

  • dry or plywood;
  • self-leveling mixture or self-leveling floor;
  • cement-sand.

The name “dry” speaks for itself, other species must be completely dried, otherwise unpleasant consequences cannot be avoided. The drying time of the self-leveling floor depends on its composition.

Floor mixes can:

  • be based on polyurethane, epoxy;
  • contain cement, resins.

Drying times vary from 6 to 21 days. The cement-sand variety will dry for at least 4 weeks.

Rough

In some cases, a rough screed must be done before finishing screed. It doesn’t have to be flat and smooth..

Its purpose is as follows:

  • align the differences in the level of the base;
  • interlock floor slabs at the base of the floor;
  • hide pipelines and other engineering communications.

It is often laid on the ground during the construction of a garage, summer cottage, veranda. The subfloor is often made of concrete. It is a heavy material and has a low vapor conductivity. It will be possible to walk on it only 7 days after the end of work. Drying takes 7 days for each 1 cm of layer. With a thickness of more than 4 cm, add 14 days for each cm. If the base has large differences, the thickness of the deepest place (from base to surface) is taken to calculate the drying time..

For underfloor heating

A screed for a warm floor has its own characteristics:

  • evens out the surface for laying the topcoat;
  • hides and fixes heating elements;
  • is a protective layer for the heating system;
  • prevents mechanical damage to the heating system.

Such a screed itself plays the role of a heater, accumulating and giving off heat. Therefore, it cannot be subtle. Its average thickness is 6-7 cm.

For a warm floor, the covering is made of different materials. If you need to provide a quick repair of the premises, you can use a dry screed that does not require time to dry..

For underfloor heating, a wet cement-based screed with sand and gravel is suitable. It takes a lot of time to dry it (up to 10 weeks). It is recommended to add a plasticizer to the composition of the cement mixture. It will help to reduce the layer thickness, therefore, the drying time will be reduced..

Gypsum screed is suitable for underfloor heating. Due to its structure, it has good thermal conductivity. The thickness of its layer can be made less than wet. Such a screed is semi-dry; it does not require a lot of water to prepare it. It will dry out in 2-3 weeks..

Optimal drying conditions

The quality and service life of the screed depends on the conditions under which the screed dries..

It is necessary to ensure constant microclimate conditions in the room:

  • Avoid drafts and do not allow direct sunlight to fall on the drying screed.
  • The best temperature is considered to be 20-25 degrees C. Temperature drop is unacceptable.
  • The moisture level is desirable in the range of 60-75%.

Lower temperatures and higher humidity levels will lead to longer drying times. In winter, it is undesirable to carry out the screed installation procedure, the minimum temperature value at which work can be performed is +5 degrees. An uncured screed should not freeze. Central heating radiators must be turned off: they dry out the air.

The screed in the bathroom requires special attention. As a rule, these rooms in modern block multi-storey buildings have good ventilation. In order to prevent cracks in the freshly laid composition, you need to create a moist environment..

Sand or sawdust should be poured onto the surface in an even layer, then over the next 10 days they should be watered. It is also necessary to moisten the surfaces in other rooms if the weather is hot outside. To do this, you need to regularly spray water..

Useful Tips

Be sure to try to create optimal drying conditions. Failure to comply with them threatens the formation of cracks and deflections. Not only the screed itself will deteriorate, but also the laid floor covering. Make sure the screed is ready before laying the topcoat. It will be useful to check its quality.

It is best to start work in late spring, early summer..

If you are doing renovations in the fall, keep a close eye on the long-term weather forecast and get the timing right. The screed must have time to dry before the temperature drops below 5 degrees C. You can supplement the composition with special fillers that increase its resistance to low temperatures. The correct screed device is the key to a reliable and high-quality repair. Observe the accuracy of all technological processes.

In the next video you will find instructions for laying a semi-dry screed..

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