Methods for installing a water-heated floor without screed

Existing standards for underfloor heating assume their arrangement in a screed floor covering, which allows you to get a reliable system with high thermal efficiency. At the same time, sometimes it becomes necessary to build such a structure in houses with wooden (parquet) floors, where a screed is, in principle, impossible. There is a technical solution that allows you to equip a water-heated floor without a screed in frame and other buildings where floors are not designed for increased loads.

Advantages of a floor without screed

When arranging a warm floor without a screed, its owner receives the following advantages:

• Upon completion of the installation work, lightweight and durable structures are obtained that provide high thermal efficiency.
• The approach allows you to save on the space occupied by the heating system - the layer thickness does not exceed 2-4 cm.
• Leaks can be eliminated very easily, since access to pipes with a carrier is not limited by anything, as in the case of a screed.
• When using special heat dissipating plates, the return from the water floor increases sharply, and the heated rooms themselves warm up faster.

It is easier to control systems without a screed by means of automation than other types of underfloor heating. The assembly takes very little time. The latter is explained by the absence of the need to prepare a concrete solution and wait until it dries. There are no drawbacks to such designs, apart from the high cost.

Types of floor heating systems

Depending on the base material, there are two ways to arrange a water heated floor: on polystyrene tiles or on a wooden flooring. Regardless of which one is chosen as the main one, before starting work, the supporting base should be carefully leveled: remove all existing irregularities and renew the decayed boards.

When choosing the first method, you first need to prepare a scheme for installing polystyrene blanks. When compiling it, it is important to take into account the dimensions of the room and choose the right dimensions for the tiles, immediately cutting them off at the place of installation. They are fastened by means of special clamps included in the delivery of the insulation material.

Materials used

Immediately before laying the heating water floors in a wooden house, the bases themselves are reliably insulated. Therefore, at the preparatory stage, you will have to select the following groups of components:

• insulation brand;
• material of water conduits (pipes);
• type and brand of insulation plates.

Heat insulators

Of the materials known and available to the user for the insulation of heating structures, basalt (stone) wool is optimal. The heat insulator is permeable to water vapor and blends well with wood, allowing it to "breathe" and prevent rotting. On the other hand, when installing mineral wool, it is important to provide conditions for the removal of vapors, since otherwise it will get wet and lose its thermal insulation properties.

For insulation of coatings on the first floors, it is recommended to use insulation based on it with a density of 40-80 kg / m³ and a thickness of up to 200 mm. For interfloor floors, the same material with a thickness of 50-100 mm is quite suitable. In this case, its task is expanded and, in addition to thermal insulation, it is supplemented by obtaining good sound insulation.

Heaters based on polymers, which include polystyrene foam, expanded polystyrene (PPS), as well as polyethylene foam, are almost impervious to moisture. When using them, the rules for laying slabs should be observed, since if the technology is violated, the wood in the places of contact with the polymer will begin to blacken and then rot.

Underfloor heating pipes

When choosing pipes laid on mats for a warm floor without a screed, the following points must be taken into account:

• Tubular products with a diameter of 16 and 20 mm are selected.
• The most suitable materials are XLPE, metallized plastic and copper. Preference is given to SP-based polymer products.

High-quality polyethylene pipes from well-known manufacturers are not cheaper than samples from metal-plastic and are almost not inferior to them in terms of performance. There is no fundamental difference between certain types of polymer products; they are equally good for warm floors.

Copper pipes are much more expensive, and their installation takes a lot of time and effort. On the other hand, none of the known materials can compare with copper in terms of heat transfer. The only thing that draws attention in this case is the inadmissibility of their use in a set with aluminum distribution plates. These metals are incompatible in their chemical structure, which is why the contact zone is oxidized over time and then destroyed.

Distribution plates

Since the thermal conductivity of aluminum-based billets is higher than that of steel products, this material is most often used in their manufacture (with the exception of copper pipe routing). At the same time, you should know that good aluminum plates are much more expensive than their galvanized counterparts (about 1.5-4 times). The observed variation in prices is associated with different thicknesses of lamellar blanks. Therefore, experts advise choosing thick-walled plates for heat dissipation that can accumulate and then give off heat energy.

Flexible corrugated pipes made on the basis of stainless steel stand out from modern technological materials. They are durable and assembled without welding or soldering. In addition, during operation, these products transfer heat well, which allows them to be used in lightweight deck structures.

Contour styling methods

When arranging the contours of the water floor, three laying schemes are traditionally used: a spiral, a snake and a double snake. The choice is determined by the design features of the apartment and the ease of installation of the pipeline system.

Spiral (snail)

This installation method is the most common and most efficient in terms of energy consumption. When it is implemented, pipes are laid along the perimeter of the room, starting from the walls and towards the center (with a decrease in the radius). Then the track is laid in the opposite direction. The main advantage of this scheme is the uniformity of heating the room by eliminating thermal "dips".

You can choose any spacing for pipe laying, starting from the smallest one of 10 mm. The snail scheme allows you to equip a heating system in rooms of any shape and area. With its help, it is possible to make one large loop, covering a room or several smaller loops, bypassing large furniture, for example.

Snake and double snake

The snake-laying method consists in placing the individual floor threads in large loops. It is suitable for rooms that need to be divided into functional zones with their own temperature regime. The route for laying the first loop runs along the perimeter of the room, after which a single snake is launched from the inside.For this reason, a well-heated coolant circulates in one half of it, and a slightly cooled one in the other, which, on average, provides the required heating uniformity. With a double snake scheme, the media supply and discharge circuits are positioned next to each other throughout the room.

Installation technology

When installing a warm floor without a screed under linoleum, it is allowed to use an insulation structure made of polystyrene sheets as a base. Typical panels for warm water floors without screed are sold in the form of slabs 3 cm thick. If necessary, reinforce the rough flooring, it is allowed to lay a foam base under them. After that, heat-distributing plates should be fixed on the surface of the heat insulator, in the grooves of which the pipes themselves are mounted. A roll material is laid on top of them, which is a substrate for the finish coating (laminate or parquet).

On a wooden base

When implementing this method, first, wooden logs are mounted on the rough base (boards), between which mats of heat and waterproofing are laid. The resulting structure is closed with wood slabs, leaving thermal gaps of the order of 2 cm near the walls. They are attached to each other by means of special clamps. All further operations for arranging a warm floor without a screed are carried out according to the same scheme as when using polystyrene sheets as a base.