How To Prepare A Solution For Pouring A Screed For A Warm Water Floor

2023 Author: Philip Bishop | [email protected]. Last modified: 2023-08-25 07:54

• Solution features
• Screed material
• Solution composition
• Preparation
• Homemade solution
• Installation nuances
• The cost

In order to economically and efficiently heat the base of the floor in the room, you should arrange a high quality warm water floor. It will not require labor and costs during operation. At the same time, the required temperature will be constantly maintained in each room. The heating elements must be placed in a well-prepared cement screed for the heated floor, which must be poured from a well-prepared mortar. Here you can do everything yourself, observing the proportions, or buy a ready-made mixture for pouring a warm water floor. In any case, the composition of the solution for screed water floor heating will be slightly different.

Solution features

The use of a mixture for a warm floor when pouring a concrete screed is somewhat different from those rooms where there is no heating. The operating mode of such a floor is somewhat more complicated, and, therefore, the requirements for the solution increase. A temperature of 50 degrees is maintained inside the cement screed under the warm floor. It becomes slightly lower closer to the base - within 30-35 degrees. The following installation errors may appear if you do not follow the installation technology and poorly prepare a solution for screed floor heating:

• On the basis, minor microcracks will begin to appear, which over time will only increase in parameters.

  

  This can subsequently lead to destruction or damage to the floor covering.
• Due to the appearance of a large number of cracks, the cement layer in the screed will begin to warp. The heating elements will also be damaged and the entire system will lose full efficiency.
• Temperature conditions will decrease not only inside the entire structure, but also near the base of the floor in the room. The cracks that appear have excellent thermal conductivity, and heat will escape through them.

To prevent all this from happening during the operation of a water heated floor, a prepared screed for pouring onto a pipeline must have a certain set of technical characteristics:

• Low setting time for cement. The likelihood of residual stress will increase depending on how long it takes for the solution to completely dry.

  

  In addition, the setting process may differ: in one area there is still moisture, in the other, everything is dry.
• Insignificant porosity. The efficiency of the water underfloor heating system will be higher if the density of the entire structure reaches its maximum. This also increases the thermal conductivity of the structure.
• High strength. Cement-sand screed of warm floors must be able to withstand external loads and mechanical stress.
• Low probability of cracking on the base. If this indicator can be achieved, then the pipeline itself will not bend and damage during operation.

Screed material

If we consider the option of a traditional screed for a water-heated floor, then the composition of the solution includes cement and sand, diluted with a certain amount of water. The most important thing in this situation is to fully observe the proportions of each component in order to get a really high-quality solution for screed a warm water floor. This, in turn, will help to obtain a protective layer for the entire system.

It is very problematic to obtain the necessary solution for screed floor heating, if you do without such modern means as plasticizers or additives that improve the quality of the fill. In addition, the surface above the pipes must have the same thickness over the entire area of the room. These components help to get rid of excess water, impart plasticity to the mass and provide a homogeneous screed composition for warm water.

Depending on the amount of water, screeds for a water-heated floor are divided into:

1. Liquid. They are the most popular. A homogeneous structure above the pipeline is obtained by uniformly filling the existing voids in the base.
2. Semi-dry. The amount of water in the solution corresponds to the minimum parameter. In this case, it will not be superfluous to add a special additive - fiber instead of a reinforcement layer. In terms of properties, it is in no way inferior to a metal mesh, but gives the finished solution the best qualities.

Solution composition

A mixture for underfloor heating screed may contain not only standard, but also additional ingredients. At the same time, there is no strict and clear indication of their total number. Special components can be plasticizers, catalysts, composition hardeners. It is worth noting that the general composition will depend on which type of screed is chosen for execution.

For liquid mixtures of pouring, the classic version of mixing is characteristic, which includes, in addition to cement, sand. The proportions of the content in the solution are 1 to 3. As soon as a certain amount of water is added to the mixture, a homogeneous liquid mass should be obtained. You can add plasticizers to the final solution. Gypsum is not used in such mixtures because the system is highly hygroscopic.

If you are preparing a large amount of a mixture for pouring a screed over a warm floor, it is better to use a concrete mixer in the work, which allows you to obtain the homogeneity of the components. The cooking process itself in this case will be less time consuming.

For semi-dry mixtures for screed warm water floors, the composition is somewhat different. In addition, the preparation of the solution is carried out in two stages. Initially, two components are mixed - sand and cement in a ratio of 2 to 3. That is, 10 kg of cement will require 1 kg of sand. Fiber is added to this after thorough mixing. A similar size of the mixture will require about 15 grams of additive. 4 liters of water are added to the resulting volume of the mixture for pouring the warm floor. The water should be mixed gradually in portions in order to eventually get a homogeneous mass. What happened should settle for 20-30 minutes, after which the second portion is mixed for the final solution - sand, water and fiberglass, in a ratio of 20 kg, 4 l, 15 g. That is, cement is no longer used for the second time …The resulting mass is used for screed over a warm water floor.

The online mortar calculator will help you calculate the required amount of screed materials.

Preparation

To make the floors durable, it is best to use M400 or M500 cement during the preparation of the solution. As for the added sand, it should have coarse grains, approximately 0.8 mm in diameter. This will protect the surface from cracks and other defects. The fine fraction of sand that is used for brickwork is not the best option. When installing a warm water floor, a thickness of at least 20 mm is required, depending on the type of screed. Use the concrete volume calculator to determine the amount.

There is one nuance that allows you to exclude a liquid solution - the portionwise addition of water. It is important here to exclude the possibility of using too much water.

Dry cement mixtures M300 sand concrete, presented in finished form. Here you no longer need to think about proportions and getting a high-quality fill. It remains only to dilute dry mixtures with the required amount of water, which is prescribed in the instructions from the manufacturer.

Separately, it is very difficult to get all the required components of a semi-dry mixture for pouring a warm water floor. For this reason, it is better not to experiment, but to buy a ready-made version for installation.

For each type of mixture, there can be plasticizers that can give the final solution more qualities and characteristics. In any case, even if they are included with the purchase, you should adhere to the mixing options indicated on the package. If it is difficult to decide which mixture to choose for underfloor heating screed, it is better to seek help from specialists or company representatives.

Homemade solution

There are several options for making a homemade solution for installing a water-type underfloor heating screed. Among them, there are five main ones that should be paid special attention to.

Basically, the components are sand, granulated slag, plasticizer, cement, or all of this together in one solution.

1. When using granulated slag, one portion of the selected cement is poured into the prepared container, followed by 3 portions of sand and 2 portions of granulated slag. But the proportions will depend on what brand of cement is used in the work. For the M200 brand, you will need sand and cement in the same amount - 2 portions each. For the M500 brand - 4 portions of sand and 3 granulated slag. You should be very careful here.
2. "All inclusive". If you mix all the components in one solution, additionally include in it a special reinforcing mesh made of metal or plastic, then the final base will turn out to be not only reliable, but also very durable.
3. Adding a plasticizer. All components in proportions are preserved, as mentioned earlier, only the additive intervenes. It will make the solution more stretchable, and all the granules will tightly fasten to each other. They will not "fear" a friend. On the packaging from the plasticizer, there is an indication of its required amount in the screed for a water-heated floor. For 1 cube of the mixture, you will need about 50-150 grams of plasticizer.

4. Use as fiber fiber component. For each cubic meter of the final solution for screed water floor heating, you will have to use about 600-800 grams of fiber. Its length must be at least 12 mm. The composition of the solution and the proportions will be appropriate. Here you just don't have to use granite slag.

   

All these options for self-preparation of a mixture for pouring will require the same amount of water for each cubic meter of solution. It will need about 210-230 liters.

Room width
Room length
Screed height
Cement	kg.
Sand	kg.
Water	l.

Calculators from wpcalc.com

Installation nuances

When installing a screed for a warm water floor, it should be remembered that there are certain subtleties here that must be known before starting work. The density of the solution used is very high, due to which a reliable structure is obtained that can withstand external mechanical influences.

The solution can also be used to equip beacons on the surface of the base in the form of cones. Laying beacons should be done in a straight line and with strict adherence to the building level. According to these beacons, the laying of guide profiles made of steel is carried out. All this will allow you to smoothly and efficiently fill the future screed.

Concrete is poured along the exposed beacons, along the lower edge of the profiles, which are subsequently removed. All possible areas with surface damage to the floor must be sealed with concrete.

We must not forget about the damper tape, which serves as a compensator for the thermal expansion of the completed screed. It is most often made from polyethylene foam. All subsequent work should be carried out exclusively after the solution has completely dried.

Depending on the composition, the time frame for the work will also differ. Mixture with less water will harden much faster.

There may be cases of obtaining an uneven surface to produce flooring such as carpet or linoleum. In this case, they resort to additional leveling using leveling compounds. The layer is insignificant and does not affect the difference in the distance from the floor to the ceiling in the room. The maximum thickness of a self-leveling fill is up to 5-7 mm. It is this indicator that the elevation differences should not exceed.

When a screed is arranged for a warm floor, the proportions must be respected without fail. This is what will allow you to get the desired result in the form of a strong and warm base.

The cost

The price will depend on whether the work is carried out independently or with the involvement of specialists. Usually, construction teams, when installing a screed over a warm water floor, take about 300 rubles for each square meter. As for the mixtures for the preparation of the solution directly, their cost will differ depending on the manufacturer and the main components.

The most popular are mixtures of the brands "Ivsil", "Perfekta", "Litokol", "Dauer". The cost can vary from 180 to 500 rubles for a standard package weighing 25 kg. When buying a mixture for underfloor heating, it is very important to know which one will show itself better in work. Without experience, hardly anyone will tell you anything about this. Therefore, experienced specialists will be the advisor in this matter.

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