Dry floor heating in a wooden house or a screed is a question that many people ask themselves when they plan to carry out repairs and equip a heating system. The second option has been more popular for a long time and has higher thermal conductivity, which means that rooms with it are warmer and more comfortable.
Dry warm floor has less weight, which does not create significant pressure on the floor beams. This is the main reason why wooden houses prefer this technology over concrete screed. It can be used both in buildings under construction and existing ones, and there is no need to wait for a long time until the solution is completely dry. When using wet technology, you have to wait about 25–28 days before starting finishing work. Installation of a dry floor is carried out much faster, there is less debris from it, and soon after the start of work, the room can be used.
The disadvantages of the design include the fact that a number of elements in a dry screed are afraid of moisture, so additional waterproofing must be used during installation.
When is dry underfloor heating used?
Dry underfloor heating is usually applied under a number of conditions in which it is the most optimal solution. These include:
- Low room height. Also, raising the floor level may be unacceptable in accordance with certain architectural or design decisions. The minimum thickness of a dry floor can start from 35 mm, while for a conventional screed it is at least 80 mm.
- Weak covers. The weight of a dry system does not exceed 30 kg per 1 m², while for a concrete screed this figure can reach 300 kg. In frame and panel houses, such a load is unacceptable.
There are several technologies for arranging a dry warm floor in a wooden house, which depend on what kind of flooring will be used in the future, and what screed materials are relevant in a particular case.
Important! Whatever technology you choose, you should always remember about the preliminary preparation of the surface. It must be thoroughly cleaned of any debris and leveled to an acceptable drop rate (2 mm per linear meter).
Dry warm floor in a wooden house under the laminate
The technology of installing a dry floor heating in a wooden house under a laminate has its own characteristics. First of all, it is necessary to choose the right coating that is best suited for these purposes. Here you need to consider the following:
- Laminate itself has a fairly low thermal conductivity and is a good heat insulator. For underfloor heating to work as efficiently as possible, give preference to boards of small thickness.
- Laminate, belonging to a high class, is resistant to temperature and humidity, is less prone to drying out and deformation.
- When choosing a substrate for a laminate, it is better to give preference to materials that are specifically designed for underfloor heating systems.
The technology of laying a dry water floor under a laminate
A water heated floor in a wooden house with a dry screed, laid under a laminate, is not the best solution in terms of heat transfer. At the same time, this method is the fastest for warming the surface, and even if it is not enough to heat the surrounding space, you will provide yourself with pleasant walking on heated boards.
Installation is carried out as follows:
- A waterproofing layer is laid on the surface.
- Bulk material is backfilled, which is ordinary sand, expanded clay screenings or a professional dry mix.
- Beacon profiles are exposed, with the help of which the future floor is leveled.
- One of the most important points is the laying of profiled aluminum plates that perform a heat-distributing function.
- Laying pipes in the recesses of the plates.
Important! After this step, check the floor surface again and make sure there are no pits or bumps. On the poured surface, you can move around with the help of a “bridge” — a sheet of plywood shifted to the right place.
- A porous tape is mounted around the entire perimeter of the room, damping noise from shock loads.
- The floor is covered with sheet materials, which can be OSB, drywall or plywood. Layers must be made with overlapping seams, fastening them with self-tapping screws at a distance of 15 cm for OSB and plywood, and 5 cm for drywall.
- A substrate of minimum thickness with the maximum available thermal conductivity is mounted.
- Laminate is being installed.
Tip: Laminate is afraid of rapid temperature changes, so if you want it to last you as long as possible, do not heat the floor more than 5 degrees a day. Also, do not allow its surface temperature to exceed 28 C.
Dry water heated floor according to Finnish technology
Dry water heated floor according to Finnish technology is a good solution for installation on logs. An ordinary concrete screed performs two main functions: it fixes the system and transfers heat upwards. Due to its heavy weight, it is not always possible to use it in wooden houses, which is why a fairly effective alternative was invented. In the Finnish version, its role is played by gypsum-fiber sheets laid in several layers between pipe loops and being the basis. The voids between all components of the structure are filled with tile adhesive. Finishing material is attached from above in the usual way.
A warm water floor on wooden logs with the help of GVL has a low weight and exerts an allowable load on the floors. Compared to conventional drywall, this material is more resistant to bending and deformation, while being characterized by increased thermal conductivity. The desired height of the screed can be easily achieved by simply bonding the slabs together with tile adhesive. Gypsum fiber sheets also have such advantages as:
- Affordable cost.
- Ease of processing.
- Environmental friendliness.
- Fire safety.
Another advantage of such a floor is that in the event of a leak, it is much easier to repair than with a concrete screed.
Tip: For dry underfloor heating screed today, not only GVL is used, but also sheets of chipboard, OSB or plywood. On sale you can find ready-made kits, the material in which already has the shape necessary for convenient installation.
How is the installation of a dry screed according to Finnish technology
Installation of a water floor according to Finnish technology involves a standard laying algorithm, regardless of the type of slabs used. In order for the heat to be properly distributed and rise up, great attention must be paid to insulating materials: a vapor barrier is laid between the lags, a heater is placed on it, and then another layer of vapor barrier that will protect the tree from condensation.
If you do not use a ready-made dry screed kit, the technology for further installation will be as follows. With the help of self-tapping screws, GVL sheets are attached to the lags, on the surface of which a further route for the passage of water pipes is applied. After that, they begin to cut the material into strips and attach it to the base.
Tip: The distance between the strips of gypsum fiber boards should be slightly larger than the diameter of the pipes. So it will be more convenient for you to carry out laying, and in the future, in any case, all voids will need to be filled with tile adhesive.
Floor in the bathroom of a wooden house with a dry screed of a warm floor
In connection with the processes taking place in the bathroom, special requirements are imposed on the structures and finishing materials used in this room. The greatest attention should be paid to the floor, as it gets the most water. If the room is located on the second floor, it is important to take care not only that the coating lasts as long as possible, but also to be sure that the lower rooms are protected from leaks.
A bathroom floor in a wooden house with a dry underfloor heating screed will cost a little more than a similar option in other rooms, since in this case more materials are used. The technology that involves the use of specialized mixtures that can be bought at any hardware store is considered the most optimal. First, the surface with a layer of vapor barrier laid on it is covered with expanded clay material, on which a dry screed is distributed. Sheets of moisture-resistant drywall are mounted on top, which will protect the system from moisture penetration from the outside. As in other cases, the perimeter is glued with a special polyethylene tape that dampens impact noise.
This technology of laying a dry warm water floor in the bathroom is the least labor-intensive and there is practically no dirt during operation. The main disadvantage in this case is the inability to withstand high loads.
One of the most important steps when laying a dry screed in the bathroom is the preparation of a waterproofing layer. Experienced specialists suggest using bituminous mastic or roll materials. With their help, you can protect not only the floor itself, but also the base of the walls, which are captured to a height of up to 20 cm.
Advice: instead of the usual moisture-resistant gypsum, you can use Knauf GVL-plates, which are strong enough and can withstand weight up to 1000 kg per square meter. This option will be optimal for rooms where it is planned to use heavy finishing materials for the floor and large-sized furniture.
Water heated floor: dry installation on foam plastic on a wooden floor
Polyfoam has excellent thermal insulation properties, and therefore it is widely used in construction for insulation of structures. Also, its advantage is its low weight, which does not affect non-overlapping. Due to these features, dry installation of a water-heated floor on polystyrene foam on wooden floors is often carried out. This material has a number of other advantages, namely:
- Characterized by zero water absorption.
- Does not pass moisture and steam.
- It has excellent sound-absorbing properties.
- Withstands heavy loads.
- Has an affordable price.
With the help of foam, you can finish the surface for a water-heated floor, even without special building skills. This material is easily cut and mounted on the surface of any configuration. Along with a low price, it is characterized by a rather long service life, for which it is appreciated by consumers. The only significant drawback of polystyrene is its flammability: it ignites at temperatures above 180 degrees, and releases toxic substances into the environment, which in a normal state do not harm in any way.
Tip: If you plan to install a warm floor with foam insulation on the ground floor of the building, it is better to give preference to slabs 8–10 cm thick. On other floors, 4–5 cm will be enough.
The technology for installing a dry warm floor on foam plastic on a wooden floor is as follows. Thermal insulation boards are the basis that is laid on the floor. Further, heat-distributing metal plates made of galvanized steel or aluminum are placed on them. They not only provide uniform heating of the floor surface, but also ensure the fixing of the system pipes inserted into their grooves. Additional rigidity is given by two sheets of GVL, which are placed on top in a checkerboard pattern. The recommended thickness of such a coating is 1 cm.
When arranging a warm water floor under a screed on a wooden base, you can use both ordinary foam plastic and more modern materials — polystyrene or foam plastic. They have a higher cost, but at the same time they significantly benefit in terms of their characteristics. Plates have different markings, which is an indicator of their density.
Tip: More comfortable than regular smooth foam are polystyrene mats with ledges (bosses). Metal plates with pipes are laid out in the space between them, where they are securely fixed and do not move during subsequent operation. The side surfaces of such plates have special assembly locks that allow them to be connected into a continuous web.
Conclusion. Dry screed is much faster than concrete screed, requires much less labor and is light in weight. All this makes it ideal for use in wooden houses, where high loads on floors are unacceptable. At the same time, it is more susceptible to moisture, therefore, it requires a more careful attitude to the construction of the waterproofing layer.