How To Install A Water-heated Floor Without Pouring Concrete Mortar

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

• Application
• pros
• Necessary materials
• Laying the contour
• Slatted wooden system
• Modular wood system
• Polystyrene base
• Flooring flooring
• Possible mistakes

Traditionally, the warm floor is installed in a concrete screed of a certain thickness. But technology does not stand still. For this reason, there was an optimal option for installing a water-heated floor, which is commonly called a dry screed. But this concept does not mean its direct entry, but simply a prefabricated screed without "wet" support. You need to figure out how to do this and what types of work will have to be done.

Application

When a water floor is being installed, a dry screed can be applied depending on certain conditions. There are several options for them, differing in the materials used.

A dry screed for a warm water floor can be arranged when:

1. Weak overlap. In this case, the concrete screed will create a serious load, for example, on a wooden base or an old slab.

   

   The dry method will allow you to avoid difficulties in work. It is about 10 times lighter than concrete pouring (about 20-30 kg per square meter).

2. With low ceilings. Creating a concrete screed - raise the level of the floor relative to the entire surface. In such cases, it is best to do without pouring the prepared solution, except in cases where all the subtleties are provided for by the design solution.
3. There is no possibility to make a concrete screed over the warm floor. This can be a high-level stage in the house. It is problematic here to deliver concrete to the place of installation. In addition, everything will require a large amount of money. It is not always very easy to prepare a mortar on site for pouring a concrete screed. In this case, it is optimal to arrange a "dry" screed.

No wet work will be done with the selected technology. The possibility of water leakage to the lower floors is excluded.

pros

If a warm floor is performed on a dry screed, then you may encounter a sufficient number of its positive qualities.

Among them, the most common:

• The design is very light when almost no load is applied to the floor. Subsequently, you can install any kind of flooring.
• The overlap can be not only concrete, but also wooden. That is, there are no restrictions here.
• Once the water floor system has been installed, you can proceed with the installation of the selected flooring option. This significantly reduces the time frame for work, which is especially important if you need to quickly move into a residential area.

• The screed turns out to be of insignificant thickness, which practically does not affect the height from floor to ceiling in the room.

  

The most important thing in this situation is to perform all the work with high quality in order to get a really effective design for heating the room from the base of the floor.

Necessary materials

When not using concrete over underfloor heating, a polystyrene or wood base is provided.

It already has special grooves where the pipes for the warm floor are placed. In addition, a metal plate is used here for proper heat distribution. When the circuit has been installed according to the chosen scheme, you can almost immediately start laying the floor covering. But before this stage, a substrate should be laid on the surface of the pipes to protect against moisture ingress. Laminate, tile, carpet or parquet are most often used as flooring.

Particular attention is paid to pipes for underfloor heating, since the quality of heat transfer and the duration of the operating period will depend on them. The most expensive, but at the same time with excellent characteristics and properties - copper or stainless steel pipes. Polyethylene materials are in great demand on the market, which stand out for their simple installation, low cost and ability to withstand aggressive environments. In terms of service life, they differ little from the same copper counterparts. In addition to water, antifreeze of various types can be actively used in such systems. They cannot have any negative impact.

Underfloor heating without cement screed requires high-quality thermal insulation. A special plate made from expanded polystyrene is used in its capacity. If you choose its optimal thickness, then there will be no heat loss. It will be directed exclusively to the base of the floor in the room to warm the air.

Wood modules can be made of chipboard or OSB.

They have special grooves for placing the pipeline, depending on the selected step. The plates themselves can have different widths of 13, 18 or 28 cm. Everything will also fully depend on the step with which the contour of the underfloor heating system is laid.

Heat distribution plates can be manufactured from metals such as steel or aluminum. In addition to the grooves themselves, they also have stiffeners. When used, the underlay becomes very tight, which allows heat to be directed over the entire surface and evenly distributed over the entire subfloor.

Laying the contour

Before making a warm floor without a cement screed, you should calculate it and draw up a preliminary schematic plan. It displays the distributed pipeline. Pipes can be arranged in two main ways:

1. "Snake".

2. "Snail".

   

But in a single performance, they are rarely found. If only the "snail" method, when the heat is evenly distributed over the entire surface. Most often, a combined scheme is arranged, when both methods are combined in one room for better efficiency.

The “snake” scheme in the usual standard design is in less demand. It is more suitable for rooms with a small area. The fact is that the warm areas on the floor will be located directly at the inlet of the warm coolant, the rest of the area directed towards its outlet will warm up less. It is best to do the "double snake" already.

Consideration should be given to the step of laying the pipeline. It is directly proportional to the selected pipe diameter. You cannot take a very small step if a large section and vice versa - large for pipes with a small diameter. You can choose a step in the range from 50 to 450 mm. If the load in the room is 48-50 W / m ², then the optimal step will be 300 mm.

The heat load can be increased up to 80 W / m ². In this case, you will have to reduce the step for better efficiency of the warm water floor. In the case of a large room area and a very high ceiling, the optimal distance between the pipe turns is 20 or 25 cm.

It should be noted that the maximum pipe length is 90 m. Otherwise, you may encounter serious heat losses, as well as a decrease in pressure in the system. For longer lengths, another contour is created in one room. A distance equal to the laying step must be kept from the wall. Usually it is 30 cm.

The final version will depend on the preferences of the artist. The main thing is to choose high-quality heating of the entire room from the floor and to the required height.

Slatted wooden system

This structure, according to which a dry screed for a warm water floor is made, is one of the wooden system. The supporting role here belongs to slats made of boards. The usual thickness of the material is 20 mm, with a moisture content not exceeding 10%.

If the selected pipe spacing is 15 cm, then the width of the strips from the boards should be 130 mm. With a step of 200 mm - 180 mm, 300 mm - 280 mm.

The strips will be used for the support system for the underfloor heating pipeline. Laying can also be done on logs or an old wooden base. If logs are made, then the thickness of the entire structure will be reduced by about 20 mm.

The diagram for a slatted wooden system is as follows:

1. The surface is completely cleaned of debris and, if necessary, high-quality leveling. For each running meter of the floor, a deviation in height of 2 mm is allowed.
2. Polyethylene serves as a layer of steam and waterproofing of the dry method of installing a warm floor.
3. There should not be a damper tape left to the side, which is attached to the walls in the room along the perimeter.

4. After distributing the wooden planks along the base, they are fastened with self-tapping screws. Laying should be done across exposed joists or support boards. Everything must comply with the established plan for the step of the pipeline.

   

   When the pipes are distributed over the surface, they are surrounded by support strips. We must not forget about the gap between them, which should be equal to 20 mm. The strips should, if possible, be rounded off in those areas where there is a bend in the water floor heating pipe.

5. The base plates are attached with self-tapping screws to the timber strips. Uniform heating of the subfloor will be achieved when the surface is covered with planks by 80%.
6. For acoustic protection, a polyethylene film is laid according to the resulting structure. During heating or cooling of the coolant, no extraneous noise will appear in the pipes.

7. After that, you can lay the GVL sheets, preferably in two layers, fasten them together with self-tapping screws. This layer will serve as the basis for further installation of the floor covering.

   

Modular wood system

Underfloor heating under a dry screed of a modular wooden system is somewhat different from a rack. The main thing here is that the heating pipes are not laid between the slats, but in special grooves of the module, which can be a chipboard, OSB plate.

All elements are connected to each other using a locking system. The result is a really flat base. The installation process is no different from rack and pinion technology. But the work is done much faster and easier. No calculations are made here due to the fact that the grooves are already available in the purchased deck modules.

Polystyrene base

The algorithm of actions, if you wish to create a dry screed for a warm water floor on polystyrene mats, is as follows:

• Preparing the foundation for work, as in the previous system.
• Layout of polyethylene film. There must be an overlap of 10-15 cm if there are several rows. The thickness of the film is chosen 200 microns. It acts as a waterproofing agent, moisture protection.
• Fastening the damper tape.

• Unfolding polystyrene mats. Fastening them to each other is carried out using the existing locks. If the thickness of the mats is insignificant, for better reliability, the edges of the material are additionally lubricated with glue and fastened.

  

• Between the protrusions located on the surface of the mats, metal plates are laid, where the pipes for heating the water heated floor are laid. In any pipe layout, there will be bends when they only fit on polystyrene mats. In this case, it is best to put a polyethylene film under it so that the structure does not create extraneous sounds.

• When the whole system is arranged, another layer of film is additionally laid, after which it is covered with all sheets of gypsum fiber board, most often in two layers. The optimal thickness of the sheets is 1 cm. The main thing here is the mismatch of the joints with each other when arranging the second layer. Here you will have to lay the sheets in a checkerboard pattern.

  

If a smooth material without grooves is used in the work, then they can be cut out yourself using a special tool - a thermal knife. Otherwise, it may be called a device that helps cut grooves. In the future, the entire installation process is identical to the polystyrene system.

Flooring flooring

When a warm floor under a dry screed is to be covered with a floor covering, then its version should be designed specifically for a warm water floor system. For this purpose, it has a special marking indicating this. But each case has its own characteristics.

So, for example, for a tile, you will have to additionally create a layer of gypsum fiber boards, which are fastened together in a checkerboard pattern with glue.

Possible mistakes

At first glance, it seems that a dry screed under a warm water floor is very simple and no difficulties can arise.

But novice performers may encounter certain mistakes that will lead to inefficient operation of a water-heated floor. To avoid this, you should first calculate the warm floor, both before the start of work and after installation. The measurements carried out can indicate possible errors, which it would be better to eliminate in advance than to spend more effort and money later. It also calculates the pressure on the base of the floor.

The ideal screed should not be heated above the temperature of the human body. There are maximum temperatures that conventional piping can withstand, depending on the material chosen. But it is recommended to create an operating temperature of no more than 55 degrees.

Another possible mistake is installing temperature sensors deep in the structure. They cannot serve for a long time and periodically fail, requiring replacement. It will be very difficult to get them out and test them for functionality.

In no case should you rush to install a warm floor. It is better to check the completed each stage and then use the high-quality operation of the system for a long time. Experts recommend leaving the system alone even for several days after the end of work. That is, it should not be turned on. When all the elements grab each other, especially if glue was used during installation, you can start using it.

You cannot save on the purchase of materials, since the system will serve for a very long time. It is unlikely that anyone would want to lay the flooring and after a year dismantle it to repair the water heated floor.

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