A floor heating system should be selected before decisions are made about flooring, layer heights and work sequence. A new house with space for a traditional screed requires a different solution than a building being renovated, a wooden ceiling or a lightweight frame structure. A well-selected system should distribute heat evenly, fit the structure and not hinder subsequent finishing stages.
Floor heating system — where to start the selection?
There is no single system that will work for every project. The choice depends on the building, available layer heights, ceiling load-bearing capacity, type of finish and pace of work. Two solutions are most commonly compared: a wet system with screed and a dry floor heating system.
The wet system is well-known and often used in new houses. Pipes are laid in a screed layer which, once set, becomes a massive heat carrier. However, this solution requires adequate height, drying and heating-up time. It cannot always be applied without changes to the design or without raising the floor level.
A dry system works differently. Pipes are run in prepared boards or panels, and heat distribution is handled by conductive elements, such as aluminium diffusers. Such an arrangement does not require a heavy screed, which is why it is chosen for renovations, wooden ceilings, frame structures and where shorter installation time matters.
At the start, it is worth answering a few questions:
- whether the project is new or being renovated,
- how much space can be allocated to floor layers,
- what load-bearing capacity the ceiling has,
- what finish will be laid at the end,
- whether the works may include wet stages,
- whether the system is also to work with floor cooling.
Only after such analysis can specific solutions be compared. The price per square metre alone says little if the system does not fit the structure or requires changes to other parts of the building.
Dry or wet floor heating system — how do they differ?
A wet system works well in buildings where adequate floor thickness has been planned from the start. Screed has a large mass, so it heats up more slowly but also releases heat for longer. With a stable construction schedule and no height restrictions, it can be a sensible choice.
A dry floor heating system is usually chosen when traditional screed would be too heavy, too high or too time-consuming. This does not only apply to renovations. Such a solution also fits well with timber, modular, frame construction and buildings where technological moisture must be limited.
A dry system is worth considering when:
- the ceiling should not be additionally loaded,
- low construction height is important,
- work is being carried out in an existing building,
- the investment concerns a wooden or timber-frame house,
- the long drying time of screed must be avoided,
- heating should respond faster to temperature changes.
This does not mean that a wet system is inferior. It has its place and will be a very good solution in many projects. The difference is that a dry system provides greater flexibility where the building imposes limitations.
Construction height and floor weight — why should they be checked before installation?
Floor height is often underestimated at the beginning, and later affects doors, stairs, thresholds, kitchen fittings and levels between rooms. With underfloor heating, each element adds another layer: insulation, slab or system panel, pipe, heat distribution layer, substrate and finish.
In new buildings, this can be foreseen in the design. During renovation, it is often necessary to fit within existing levels. A low underfloor heating system then allows avoiding problems with excessive raising of the floor.
Weight is equally important. Screed accumulates heat well, but adds considerable mass to the building. On a reinforced concrete ceiling, this is usually not a problem. On a timber ceiling, in an older building or in a lightweight structure, it can become a serious limitation.
Before selecting a system, the following must be checked:
- type of ceiling,
- permissible load,
- total thickness of layers,
- acoustic requirements,
- method of insulation,
- planned floor finish,
- system manufacturer’s recommendations.
This is the data that should be provided to the installation designer or supplier. This ensures that the underfloor heating system is matched to the building, not just to the floor area.
Azzura ThermoFloor — dry system for underfloor heating and underfloor cooling
Azzura ThermoFloor is a system for underfloor heating and underfloor cooling in dry construction. The solution is based on routed P5 boards, prepared for pipe routing, and an aluminium diffuser that helps distribute heat across the floor surface.
Such a system works well where traditional screed is not the best option. The boards create an organised base for the installation, and the absence of wet screed shortens the work process and reduces floor weight. This is particularly important in renovations, timber-frame houses, wooden buildings and lightweight structures.
Several features of this type of solution are worth noting:
- pipes are routed in prepared channels,
- aluminium diffuser supports even heat distribution,
- the system reduces the need for wet layers,
- P5 board provides a stable base for further layers,
- the solution can be considered for underfloor heating and cooling.
The greatest advantage is predictability. The installer does not lay pipes in random material and does not adjust the system “on site”. They have a ready-made layer that organises the installation routing and facilitates control over the entire floor.
How to Choose an Underfloor Heating System for Panels, Tiles or Boards?
Underfloor heating ends with what the user sees and walks on: tiles, panels, boards, vinyl or other finishes. This final material has a significant impact on the effectiveness of the entire system. If it conducts heat poorly or is not approved for underfloor heating, even a well-designed installation may perform poorly.
Ceramic tiles work very well with underfloor heating. Panels, wood or vinyl can also be a good choice, but require checking the manufacturer’s parameters. Information that they are “suitable for underfloor heating” is not sufficient. Attention must be paid to thermal resistance, maximum surface temperature and recommended substrate.
Before selecting a finish, it is worth checking:
- whether the material is intended for underfloor heating,
- what thermal resistance it has,
- what substrates can be used underneath it,
- how it reacts to temperature changes,
- whether the manufacturer specifies a maximum operating temperature.
In a dry system, the stability of the entire floor is also important. The finish must have adequate support, and the layer arrangement should comply with the documentation. Random material substitutions may weaken the heating effect or reduce the durability of the floor.
Most Common Mistakes When Choosing an Underfloor Heating System
Mistakes with underfloor heating are rarely visible immediately. They more often emerge over time: the floor heats unevenly, the room responds with a delay, the finish does not maintain stability, or the floor level turns out to be higher than anticipated.
The most common mistakes are:
- choosing a system without checking the load-bearing capacity of the floor slab,
- omitting the total height of layers,
- selecting a finish without analyzing thermal resistance,
- lack of installation design,
- excessive pipe spacing,
- abandoning heat distribution elements,
- mixing materials from different systems without consultation,
- treating renovation the same as new construction.
Many problems begin with the assumption that every underfloor heating system works similarly. It does not. Differences in weight, height, reaction speed and heat transfer method are significant enough that they should influence the decision at the design stage.
Underfloor Heating System — Most Frequently Asked Questions About Selection, Installation and Application
What underfloor heating system should I choose for a house?
For a new house, you can choose a wet or dry system, depending on the floor design, layer heights and schedule. A wet system will work well where a screed can be laid. A dry system is worth considering for lightweight structures, renovations and places where floor weight needs to be limited.
What is the difference between a dry and wet underfloor heating system?
In a wet system, pipes are embedded in screed. In a dry system, they are routed in boards or panels, without a traditional screed. Dry installation is usually lighter, lower and faster to install, but requires properly selected layers and finish.
When is it worth choosing a dry system for underfloor heating?
A dry system is worth choosing for renovations, timber floors, frame houses, lightweight structures and projects where there is no room for a thick or heavy screed. It is also a good direction when the work is to proceed more efficiently and without a long drying time.
Can underfloor heating be used with a heat pump?
Yes. Underfloor heating works well with a heat pump because it can operate at a lower supply temperature than traditional radiators. However, the pipe spacing, insulation, controls and floor layers must be correctly selected.
Is a dry underfloor heating system suitable for renovation?
Yes, it is often particularly useful in renovations. It allows the installation height to be limited, the weight of the floor to be reduced and the need for a heavy screed to be avoided. However, before installation, the load-bearing capacity of the floor and the planned finish must be checked.
Is underfloor heating suitable under panels?
Yes, but the panels must be approved by the manufacturer for use with underfloor heating. An appropriate underlay and low thermal resistance of the entire finishing layer are also important.
What to watch out for when choosing an underfloor heating system?
The most important factors are: building structure, installation height, system weight, heat source, pipe spacing, insulation and type of flooring. It is advisable to avoid accidentally mixing elements from different systems without technical consultation.
