During the heating season, the correct installation of water floor heating is crucial. In order to avoid unpleasant surprises and ensure efficient operation of the system, there are a few rules that are worth following. The basic element of the installation is a layer of screed, which is intended to cover the pipes. The screed is a mixture of sand, gravel, water and a binder, usually cement. In order to increase the plasticity of the screed and ensure better adhesion to the pipes, it is recommended to add special emulsions, called plasticizers.
When laying screed for underfloor heating, the process should be divided into two stages. The first stage consists in laying the screed up to the height of the heating pipes, and the second stage – immediately after starting the bonding – consists in laying the screed up to the correct height. After making the screed, it should be seasoned for about 20-28 days. After the bonding period, before finishing work, the base should be heated to reduce humidity. Strictly follow the manufacturer’s heating recommendations to avoid damage to the primer. It is also important that the temperature in the room during the pouring of concrete and during the setting process does not fall below +5°C and remains at a constant level.
What to look for?
The expansion joint between the floor slab and the building structure cannot be forgotten. An expansion joint with a width of at least 0.5 cm allows the natural expansion of the floor under the influence of temperature. Minimizes the risk of screed damage, such as cracks, deformations or scratches. Expansion joints should be made along all walls, pillars and door openings. Additional expansion joints should be used in larger rooms with an area of more than 30 m2. And also for long floor sections over 7-8 m.
When laying heating pipes, ensure that they are properly coordinated with expansion joints to minimize the number of passes through expansion joints. If it is necessary to lay pipes in places such as door thresholds, they should be placed in plastic sleeves to prevent damage to the pipes when the underlay is moved. The length of the sleeve should be 40-50 cm. Appropriate safeguards should also be used when pipes exit the floor to manifolds. To make expansion joints in the screed layer, edge strips, wooden strips or ready-made solutions offered by manufacturers are often used. Expansion joints must go through all layers of the floor, from thermal insulation to the finishing layer.
Finishing the heated floor
When it comes to the finishing layer of the floor with underfloor heating, it is recommended to use materials that will not insulate the heat flow. The lower the conductive resistance of the finishing layer, the more heat will be given off. On the other hand, materials with greater insulation will allow for a more even distribution of temperature in the room. The adhesive must be heat resistant up to 50°C and permanently elastic to accommodate shear stresses between the substrate and the floor. Carpet, PVC and laminate flooring can also be used as a finishing layer. However, they must be properly adapted for laying on underfloor heating. It is important to lay these materials precisely to avoid creating gaps that can act as additional thermal insulation.
Summary
If you plan to finish the floor with wood, the thickness of the parquet or boards should not exceed 1 cm. The wood should also be properly dried. In the case of wood with higher humidity, cracks may appear during the heating season, which is due to the hygroscopic properties of the wood. Many manufacturers also recommend avoiding the use of wood in hotter areas. It is worth remembering that the correct installation of a floor heating system will ensure comfort regardless of the type of floor.
