Thermal isolation

Main objective: to discourage thermal losses. The heat should increase in the heat of the pex tubes. It can be run from any material allowed in the building as a thermal insulating layer for use in building gender.

The thermal resistance of the insulation layer must be greater than the total thermal resistance of the pex tubes of the heating layers (including the finish coating, the pex tubes) with a maximum thermal load of underfloor heating. The higher the heating load, the thicker the insulation layer.

The most common insulation material in modern construction is Pex polystyrene. We recommend using Pex polystyrene with a density not lower than 35 kg / m3 (pex tube). Low Density Polystyrene Pex is not resistant to mechanical stress, it is destroyed when not used carefully and loses its mechanical and thermal insulation properties, especially in the context of ongoing civil engineering works is a long time from the end of the pex pipe mounting units Underfloor heating water pipe to fill your headphones. Pex Polystyrene with a density of 50 kg / m3, as well as extrusion, is used in systems with high mechanical loads (auto centers, warehouse complexes with heavy loaders, heated roads, etc.).

Reinforcement fabric. Pex rails

The pitch of the reinforcing mesh and the diameter of the cell of the reinforcing mesh of the bar is selected depending on the construction of the floor, depending on the characteristics of the premises (pex pipe), its destination, loads, etc. In the standard design for ease of installation a grid is used, usually 150x150mm cell, 4-5mm rod. Drops in polystyrene Pex, is a real cause of the design contours of water Underfloor heating. Pex pipes are attached to the grate with plastic fasteners.

To give additional strength to the screed, in some cases it is a double reinforcement: a second layer of reinforcing mesh is laid on the contours of the water pipes Underfloor heating. Pex Rails in Europe due to the large spread of the “snake” stacking type is widely used in mounting rails and clips, which are arranged on polystyrene.

Sometimes the fastening of the reinforcing mesh and / or the mounting rails use U-shaped Pex anchors. Pex pipe contours vschelkivaetsya mounting rails in the grooves (pex pipe grooves). In this case, apply a reinforcing layer, they are laid over the pipes.

Pex damping tape

The buffer tape is placed around the perimeter of the premises before the concrete is poured. It is used to compensate for the thermal expansion of concrete sleepers during heating. Polyethylene foam is generally produced with a width of 100-120 mm and a thickness of 8-10 mm.

Pex tubes

Water pipe contours Underfloor heating stacked according to the drawing (Water underfloor heating project). The number of meters of pipe is documented and recorded in the table of the balancing tank, attached to the project. Based on the mounting evidence, the structural engineer decides on the need to adjust the tuning (roll) of the pex tube table. As a general rule of thumb, unlike the actual length of the project pipe by up to 10%, the balancing tank amendment is not required.

Hydrotesting

Before filling the contours with water, it is recommended to heat the underfloor heating with concrete to check the tightness of the system. System verification is carried out in accordance with national building regulations. Typically, the system checks the pressure at 3.4 bar for 24 hours.

When filling the Pex refrigerant system, the opening and closing circuits are consistent. Get complete removal of air from Pex pipes and equipment.

It is recommended to leave the Underfloor Heating system under pressure throughout the course of the remaining civil engineering works (device couplers, mounting finish coatings), periodically monitoring the pressure level which, at any stage, ensure that during the production of other works not a watertight system.

Concrete screed

The poured concrete is carried out after mounting the underfloor radiant water contours and test activities. The thickness of the screed must be at least 30mm above the pipe, mark the recommended concrete not less than the M-300 (V-22, 5). In special cases (heavy weight and / or thermal loads on the heating stove, etc.), the thickness of the concrete braces and brand designers are calculated based on the characteristics of the object (in this case, it is necessarily a separate calculation of the heating panels). The minimum thickness of the screed (30 mm above the pipe) is mainly due to the characteristics of lack of resistance and to achieve uniformity of temperature distribution on the surface of the heating panels.

When the thickness of the screed greater than 150 mm requires separate calculations of the thermal regime of the Pex heating panel with the introduction of special correction factors.

For reference: the weight of 1 square meter of ties with a thickness of 50mm is 350-400 lb.

The greater the thickness of the flange, the longer it takes to display it in a stable heating regime from the time of embedding.

A thicker rule equates to a larger inertia system. The lower the thermal conductivity of the ties, the higher the required temperature of the coolant.

Compensatory gaskets If, in relation to the large extension of the heating panel, it is divided (every 15 meters) into parts of compensatory sutures, the tube, the backcross seam is placed in a corrugated protective tube (300 mm to the left and right of the extent of the seam). It is recommended to pack intact heating circuits within an equalization ground, that is, expansion joints should cross only the pressure and return piping circuit.

The warm water system allows the use of any plasticizer in the concrete. Widely used in modern construction has received a device with plastic binding fibrils.

To speed up the drying of the concrete slab, which usually takes 3-4 weeks, and to achieve an acceptable level of relative humidity, you can connect the underfloor heating to the heat source (including a temporary scheme). The recommended temperature of the coolant in this case should not exceed 30 ° C. The practice of water systems, using the “drying” mode of underfloor heating, has shown many examples of shortening of construction, especially in sites with large areas.

The relative humidity of the concrete must not exceed 85%. In the case of laying parquet or other wood paneling, the relative humidity should not exceed 60%. In any case, it is advisable to follow the instructions of the manufacturers and suppliers of materials and technology to comply with the construction and production works. Therefore, it generally requires 2 to 4 weeks from the time of pouring the concrete screed before placing the finish coating.