Cross-linked polyethylene for underfloor heating: system arrangement rules

The system warm floor allows you to significantly increase the level of comfort in the house. The heat generated by the system is distributed in a comfortable for the owners area, does not stimulate the movement of air with dust. With certain skills and knowledge, you can make the floor with a polyethylene pipe yourself.

We will tell how to apply the most inexpensive material in arrangement of floor heating. In the article presented by us, we have discussed in detail how to correctly put cross-linked polyethylene for a heated floor, with what step and according to which scheme to arrange it. Our tips will help to build a perfectly functioning system.

Crosslinked polyethylene: features and benefits

Cross-linked polyethylene is a variant of ordinary ethylene, reinforced by chemical, physical or complex effects. Thanks to this procedure, in addition to the characteristic longitudinal links in the polymer structure, transverse joints appear.

As a result of production manipulations, polyethylene products obtain dimensional stability, acquire increased strength to deformation, and exposure to high temperature. The process of processing with the introduction of the polymer of organic compounds is called "crosslinking".

Depending on the technology, it is performed either before or after extrusion. Long pipes in reels of cross-linked polyethylene are used for arranging heating systems because of their high tightness - the risk of leakage is reduced to zero.

Technical characteristics of linear products made of cross-linked polyethylene:

• external diameter of 10-200 mm;
• wall thickness 2-5 mm;
• average specific weight is 110 g / pogm;
• density is 949 kg / m³;
• deformation at temperatures above + 200º C, melting + 4000 ºС;
• average working pressure is 6 MPa;
• average thermal conductivity - 0.4 W / mK.

Given that the maximum temperature of the coolant is + 90º С, and the pressure does not exceed 4 bar, it can be concluded that pipes of this type are excellent for installing underfloor heating.

Compared with steel corrugated or copper pipes, also often used for underfloor heating, these products have the following advantages:

1. Resistance to corrosion processes. The material is not susceptible to corrosion, corrosive environments, does not deform with high acidity, alkalinity, as well as upon contact with organic substances.
2. Excellent strength characteristics. Resistance to static and dynamic loads, resistance to tearing, bending, stretching, etc. Pipes without damage tolerate exposure to low and high temperatures.
3. Stable bandwidth. On the walls of the pipeline is not deposited sediment, reducing the internal diameter of the pipe.
4. Elasticity. Flexible pipes do not burst when bent under any radius.
5. Environmental Safety. When heated, the products do not emit toxins.

With proper installation and compliance with the recommended thermal mode, polyethylene warm floor will last at least 50 years. Fully the cost of creating a system pays off in 1-2 years.

Step-by-step installation of a heat-insulated floor

The technology of the device consists in the gradual creation of layers stacked in strict sequence. The total thickness of the system will be 10-20 cm, depending on the characteristics of the screed, heat insulation and reinforcement used.

Preparatory work before the construction

It should be borne in mind that the average load created by the “cake of the warm floor” on the foundation of concrete is 300-350 kg / m2. Therefore, the overlap should be calculated on such a weight.

When constructing a heated floor using pipes made of cross-linked polyethylene, the following work steps are required:

1. Choice of pipes. The calculation of the length of the contour. Drawing up the scheme of laying.
2. Preparation of the base. Laying waterproofing and insulation.
3. Installation of pipe contours. Hydraulic testing.
4. Fill the screed and finish the selected floor covering.
5. Putting the system into operation.

When buying collectors, it is better to give preference to devices with balancing valves and flow meters, which will simplify the system setup in the future, and in the event of a malfunction will help to quickly identify the problem circuit.

For the construction of a heated water floor will require the following:

• water heating boiler for heating the coolant;
• expansion tank;
• circulation pump for forced movement of the coolant;
• plumbing accessories: fittings, ball valves;
• bobbin of cross-linked polyethylene pipes;
• fasteners for insulation plates and PE-pipes;
• distribution manifold;
• damping tape;
• insulation and reinforcing mesh;
• solution for screed or a mixture of "dry screed".

All materials should be prepared in advance in order to avoid being distracted by shopping malls and purchasing additional components in the process of arranging a heated floor.

Selection and creation of pipe laying patterns

For residential premises, three laying patterns are used: “snake”, “shell” or “snail” and “twin helix”. Spiral "snail" - the easiest option, providing a uniform distribution of thermal energy. According to this scheme, water heated floors are most often constructed, since all angles are at 90º.

Laying on the "snake" scheme is somewhat more complicated, because it is associated with turns of 180º. But it is great for building a system of cross-linked polyethylene, because the pipes made of this material bend freely, the throughput in the loops is almost not reduced.

The choice of laying pattern depends entirely on the characteristics of the room. If we are talking about the arrangement of large-sized areas, the laying is performed according to the “double helix” scheme. It is also used if it is planned to select zones according to the intensity of heating, for example, in the hall, in front of the entrance group or in front of a volume terrace.

For simple spiral and serpentine schemes, the optimal contour length will be 60-80 m. For rooms where the length is much larger than the width of the allowed circuit length of 100-120 m, but on condition that used pipes diameter.

The distance between the pipes (pitch) is 10-35 cm. The wider the step, the less heat will come from the floor.

At peak points where the highest heat losses are observed, the stride width should be minimal, for example, near the entrance door it should be 10-15 cm, increasing when approaching the center rooms The distance of the pipes from the walls along the perimeter is 30-45 cm.

Details of the schemes and options for laying the pipeline of a warm water floor are described. in the articlewhich we recommend to read.

Selection and calculation of the number of pipes

When choosing pipes from cross-linked PE, it is necessary to decide which diameter of the product should be purchased. As practice shows, the best option for the device of a heat-insulated floor in your own house or apartment located in the first floor will be a 16 mm pipe.

For rooms whose length is several times larger than the width, pipes of 20 or 25 mm can be used. Wall thickness is suitable standard - 2 mm.

To calculate the required number of polyethylene pipes, you can apply the formula:

D = S / M x k

Where:

• D is the estimated length of the pipe;
• S is the area of ​​the heated floor;
• M - middle step chosen according to the scheme;
• k - safety factor (for rooms up to 30 m2 it is 1.1, more than 30 m2 - 1.4).

It should be remembered that the maximum length of a pipe made of cross-linked polyethylene depends on the diameter - the larger the diameter, the longer the heat carrier pipe can be. For products with a diameter of 16 mm - up to 90 m, 20 mm - 120 m, 25 mm - 150 m.

How to complete calculation of water heated floor, including the definition of heat loss and circulating equipment power, you will learn from the article recommended by us.

Preparation of the base for pipes

When the calculations of the required number of pipes are completed, you can proceed to the preparation of the base for the contour of a water heated floor.

This phase includes the following workflows:

• removing old flooring and old screed;
• laying of the insulation layer;
• installation of insulation;
• laying reinforcing mesh;
• sticker damper tape.

First you need to align the base so that the drops were not more than 5 degrees (check the building level). For leveling, you can use a sand mixture with subsequent tamping or self-leveling compounds. The leveled base is cleaned from dust and debris.

Then lay the waterproofing layer. The simplest form is plastic film.

If you have financial opportunities, it is better to use high-quality Russian or European waterproofing in the form of a polymer membrane. It not only reliably protects the floor from moisture, but also allows the system to “breathe” the warm floor.

For waterproofing comes the turn thermal insulating substrate, as which you can use extruded polystyrene foam. This is the cheapest and most effective way to reduce heat loss.

Of the new heaters, cork heat insulator is considered the most environmentally friendly, but its cost is ten times higher than that of the most expensive expanded polystyrene. Insulation plates 5 cm thick are attached to wooden guide rails using dowels-nails. Between themselves, the plates are fastened with glue and special brackets.

As for the reinforcing mesh, when using polystyrene plates in its laying there is no need - the pipeline is laid directly on the insulation. The use of the grid is justified if another waterproofing layer is laid over the insulation.

If there is no desire to overpay for insulation, then you need to keep in mind that there are special insulation blocks for installing underfloor heating that have pipes for pipes. Such blocks significantly increase the cost of creating a warm floor, but it is very convenient to use them.

After the mesh layer, it's time to stick a compensating damper tape. This is done simply - a penolex tape is glued around the perimeter of the room, which compensates for the expansion of the future concrete screed. Instead of a damper tape, even polystyrene foam can be used.

After preparation of the base, the heating boiler and the manifold distribution node are mounted. The boiler is connected to the water supply and supply system (gas or electricity).

Information about choosing insulation matsused in the device of water heated floors, details the next article, which we advise you to read before planning the installation.

Installation of polyethylene pipes

Laying of a warm floor is carried out by contours according to the scheme chosen in advance. The contour is a closed pipe ring, which, on returning to the collector, is connected to it by means of a fitting.

For small rooms arrange 1-3 contour. To simplify installation, it is recommended to apply an approximate marking on expanded polystyrene plates. With markup, it will be easier for you to lay polyethylene pipes and check the step size.

Before the start installation of warm floor piping It is also necessary to decide how the pipe joints will be made and how the polyethylene pipes will be attached to the insulation.

The fact is that the connecting pipe connections can be carried out:

• welding;
• crimp fittings;
• press fittings.

The last option is the easiest to perform and reliable. To connect the pipes, it is necessary to install the movable coupling, and then with the expander, carefully increase the internal diameter of the pipe to the required size.

Fully tighten the fitting and slide the sleeve over the pipe over it. Pressing compound withstands prolonged exposure to high temperatures and pressures up to 10 MPa.

As for the method of fastening polyethylene pipes to the insulation, it is important if you use regular polystyrene foam.

There are several mounting options:

• tightening clamps made of polyethylene;
• steel wire;
• the clamps which are fixed by the stapler;
• locking tracks.

The easiest and most economical method of fastening - clamps. Consumption is 2 pieces per 1-1.5 m.

There are 10 rules for installing cross-linked polyethylene for underfloor heating:

1. When laying bends, sharp creases of the material are not allowed.
2. Installation work is carried out at a temperature not lower than +18 C.
3. After the pipe has been brought in from the cold, you must wait until it reaches room temperature.
4. The maximum turning radius for pipes with a diameter of 16 mm should be 10-12 cm.
5. In the process of laying it is not desirable to change the selected layout of the coolant.
6. Cutting of extra length should be carried out immediately before it is connected to the distribution manifold.
7. You can not step on, put heavy things, put the tool on the pipe.
8. It is recommended to use large sheets of plywood to move along the laid pipes (if necessary) to reduce the load on the coolant.
9. To increase the rate of heat preservation, pipes coming out from under the floor at the point of connection to the collector assembly can be enhanced by thermal insulation.
10. The pipes must lie flat, without torsion and excessive tension.

After laying the contour, the pipe returns to the collector and is connected using a fitting that is sized according to the size. After this, a system test is carried out, the purpose of which is to detect defects before the system is hidden under a screed.

For testing, you need a household compressor, which can give a pressure of 4-6 bar. Heat carrier with the help of a compressor is fed into the pipes and left for 6-12 hours. When shooting the securing clamps, they must be re-applied 5 cm below the previous attachment point.

The rules of the device tie

If the hydraulic tests were completed successfully, the depressurization of the pipes did not occur, and the system was completely filled with coolant, the pipe installation phase was completed. Now you can proceed to the device screed and to the finishing finish.

For screed devices It is necessary to use commercially or independently prepared mortar based on cement grade M300. The minimum height of the screed, providing protection for pipes made of polyethylene, is 3 cm above the laid pipe. This thickness will be optimal for uniform heat distribution.

In most cases, the screed is continuous without temperature joints. Thermal seams are needed when:

• the room has an area of ​​more than 33 m2;
• room length more than 10 m;
• the room has a complex configuration.

To create seams used damper tape. Heat guns are treated with sealant.

Do I need to reinforce before pouring the screed? There is no single answer to this question. Experience shows that the system functions perfectly without reinforcement, but at the same time, the reinforcing layer gives the coupler additional strength. For reinforcement, you can use made of metal or plastic mesh 100x100 mm.

Also, reinforcement will be useful only if the reinforcing mesh will not just lie on top of the pipe system, but “sink” in the solution, while freezing, being inside the screed.

The correct reinforcement device complicates the laying of the screed, so when there is no experience or confidence that everything can be done correctly, this step can be skipped. After pouring the screed, the system can be started no earlier than in 25-30 days.

Putting the system into operation

After the final curing, the embedded screed can be fed into the system. heat carrierwhose temperature should be no higher than + 26ºС.

The algorithm for commissioning a warm floor system made of cross-linked polyethylene is as follows:

• collector we connect to the supply and return pipelines;
• all contours at the same time open with the help of cranes on the collectors;
• valves of air extractors are installed in the “open” position;
• we start the circulation pump;
• set the temperature + 25-26º С;
• the pressure in the system is raised to the working 1 bar;
• close all contours with cranes except the longest;
• we write down all positions of flowmeters and balancers;
• open the next contour along the length and with the help of a crane align the pressure along the first contour.

In this way, we connect and balance all contours of a warm floor. Evaluate the performance of heating is possible only after 2-3 months of operation.

With features and rules of the device of floor heating on the wooden basis will introduce the articledetailing the rules of design and construction of the system.

Conclusions and useful video on the topic

The rules for calculating the heating floor system are given in the video:

After laying the pipe, it is important to test it before performing further installation work. About this in the video:

Home craftsmen often make mistakes when assembling a heated floor. The main problems of mounting polyethylene pipes are covered in the video clip:

Properly chosen and installed underfloor heating at no extra cost will make housing warm and comfortable. The technology of a floor heating system made of polyethylene pipes is simple and can be used not only by professional builders, but also ordinary citizens. If you follow all the rules and recommendations, the system will regularly serve you for a long time.

And you had to lay plastic pipes when installing a heated floor? Perhaps you know the technological nuances that are not noted in the article? Please write 0 comments, ask questions, post a photo on the topic in the block below.