Floor construction in detail - floor construction, costs & Co.

• unfinished floor
• Know what you want
• Floor construction - different layers
  • Static load capacity
  • flatness
  • Sound insulation Airborne sound
  • Sound insulation structure-borne noise
  • Sickerschutz
  • heat source
  • Flooring
• Planning saves costs

Budget planning is the most important thing when it comes to the planning of a new construction or reconstruction. "What can I afford">

unfinished floor

If we want to talk about the cost of a floor, then we set the starting point on the raw floor. For most houses, this consists of concrete, and in lightweight houses also made of chipboard. In any case, the raw floor is an integral part of the shell. It is either part of the floor slab or the top of the false ceiling. Concrete floors are only roughly removed and smoothed surfaces of artificial stone. The raw floor has only mechanical qualities. High structural strength and airborne soundproofing are the only features expected of it. Starting with a minimum thickness of 20 cm, an unfinished floor costs about 50 euros per square meter, including shuttering material, concrete, transport and steel inserts. Regardless of how the unfinished floor is constructed to the finished floor, but in any case, a leveling and leveling is necessary. For this, again with about 2-3 euros per square meter can be expected.

Know what you want

The prices for the floor depend on the extent to which the construction is to be carried out. A tiled garage requires neither footfall sound insulation nor underfloor heating. A bathroom often has only a thin-layer underfloor heating for tile heating. A living-dining room with real wood parquet is never executed without Tritschalldämmung. Therefore, you should always specify the exact function of the floor in advance, in order to come to a correct planning of the budget.

Floor construction - different layers

Floor in the living area must have the following characteristics:

• Sufficient static load capacity
• flatness
• Comprehensive sound insulation
• heat protection
• Safe against leakage of liquids
• possibly active heat source
• attractive surface
• easy to clean surface

Static load capacity

The sufficient static load capacity becomes more and more challenging as more demands are placed on the floor. The stability of the raw floor is only the beginning. Impact sound insulation, screed and surface layer must also be sufficiently static to not cause any damage during normal use.

flatness

The flatness of the floor is achieved by the screed. This is a layer of fine but very strong concrete. Like reinforced concrete, the screed is reinforced by the insert of a mat. This prevents shrinkage cracks and distributes the compressive stresses that inevitably arise due to the point load from parked furniture. For screed you have to expect 18-29 euros per square meter in costs.

Sound insulation Airborne sound

The sound insulation is differentiated into protection against airborne and structure-borne noise. Airborne sound is the sound that transmits through the air. It is already guaranteed by the solid concrete floors. In wooden houses, for example, in prefabricated houses made of chipboard, the shield against airborne sound always certain, inevitable compromises are required. That's why larger multi-family houses in this construction are difficult to implement.

Sound insulation structure-borne noise

However, the structure-borne sound transmits itself the better, the more massive and dense a building is executed. Brick houses with concrete floors are inferior to the houses in lightweight construction in this point. Nevertheless, the same measures are taken in both types of houses to shield them against impact and structure-borne noise.

The established method for this is the installation of a floating screed. In this case, a footfall sound insulation in the form of foam boards is installed under the leveling layer. At present, there are only a few alternatives for PU-based foam boards for impact sound insulation. However, these PU foams are becoming increasingly problematic: By means of a legislative amendment, the disposal of mixed waste, which is interspersed with rigid PU foam, is very difficult and correspondingly expensive. It is therefore fair that the cost of dismantling must be taken into account when installing floating screed. In the worst case since the legislative amendment of September 2016, these are at an enormous 7000 euros per tonne.

Therefore, a well-intentioned advice from us: When installing a new impact sound insulation, either use a dry system, which can be neatly separated and properly rebuilt. Or use a material that is easy to dispose of. Already available materials are wood fiber boards, foam glass or pressed mineral wool plates. However, these are much more expensive to buy than the established PU foam boards. In addition a comparison:

Styrodur plate (pressure-resistant PU rigid foam): approx. 3.50 / m²
Wood fiber board: about 5 Euro / m²
Mineral wool: approx. 15-20 Euro / m²
Foam glass: approx. 400 Euro / m³, that corresponds to approx. 15 Euro per m² with a height of 5 cm.

The alternatives to rigid polyurethane foam are also much more beneficial in building biology and fire protection technology. In the cheapest version, the square meter of floating screed costs 12-15 euros per square meter. If another insulation material is chosen as the PU foam panels, the price can more than double. When decommissioning, however, this additional investment pays off again.

In any case, the impact sound insulation also provides a thermal insulation of the floor. On the ground floor this may not be enough if there is an unheated cellar underneath. A simple masking of the basement ceiling with thermal insulation panels can quickly and easily prevent the cooling of the floor.

Sickerschutz

Soak protection is achieved by built-in dampers. These are simple PA films or bituminous membranes that cost only a few cents per square meter. Nevertheless, they are very important and must not be forgotten or saved. This is especially true for rooms that are used for critical purposes: laboratories, paint and paint stores, workshops or production halls must definitely have reliable seepage protection in the ground. If this is missing, this can lead to the decommissioning and use ban.

heat source

The "active heat source" is the underfloor heating. There are many different designs available for this comfortable and value-enhancing feature. The first distinguishing criterion is the choice of heating medium. Tobe offered:

• Electric floor heating
• Warm water underfloor heating

Electric underfloor heating

Electric underfloor heating systems are very thin. They have a height of only 2-4 millimeters. Electric underfloor heating systems are ideal for retrofitting, ideally on a floor on which a floating screed has already been installed. The impact sound insulation also takes over the thermal shielding to the ground. So only the room is warmed up, for the heating of the concrete floor no energy is wasted.

An electric underfloor heating costs between 13-40 euros per square meter . The prices depend on the mat size. The larger the selected heating mat, the lower the price per square meter. It is placed directly under the top floor covering and is very easy to install. However, an electric underfloor heating can hardly be installed individually. You always have to rely on the delivered mat sizes. Cropping and other adjustments are not possible with this technique. They have a higher energy consumption than hot water underfloor heating and a much longer lead time. That is why electric underfloor heating systems are especially interesting for less used rooms or buildings, such as privately used holiday homes.

Underfloor heating with hot water

Hot water underfloor heating systems are also available in numerous versions. They have a height of 22-60 millimeters. Technically, they are designed so that they can be laid directly on the unfinished floor. A hot-water underfloor heating brings along their impact sound insulation, so that high costs can be saved through clever planning. There are three different types of hot water underfloor heating systems, which must be distinguished:

• floor heaters
• Floor heating in liquid screed
• Floor heating in dry construction

Floor warmers are extremely thin and low performance hot water underfloor heating systems. They only serve to bring the floor to a comfortable temperature, but have hardly any heating effect on the room. This must be heated when using a Bodenwärmers by a separate radiator. Typical applications for floor warmer are bathrooms. You still like to choose hot water underfloor heating here, because they offer a much faster start-up time than electric underfloor heating and also promise especially in wet rooms such as bathrooms a plus in safety. Thin-layer underfloor heating systems are approx. 8 millimeters high and cost approx. 25 euros including cast screed.

Underfloor heating, which is laid in liquid screed, is the most common design of this feature. They promise high comfort and have low operating costs. Hot-water underfloor heating systems are basically the ideal supplement to modern heating systems such as solar thermal energy, heat pumps or condensing boilers. Since hot water underfloor heating in the reason consist only of a floor insulation, a hose system and brackets for the heating circuits, they are very low in terms of material costs. Prices start at around 10 euros per square meter. If you want to lay the underfloor heating, the prices including installation and top layer of liquid screed start at about 50 euros per square meter. But realistic are more likely to 70 to 100 euros per square meter when installed by a specialist. The underfloor heating itself is relatively easy to install itself. But at the latest when installing the cast screed should be resorted to a specialist. If attention was consistently paid to the non-bonded moisture barrier, it is relatively easy to dismantle a floor heating system.

Drywall underfloor heating systems are particularly well suited for installation by DIY enthusiasts. They cost about 35 euros / square meter . Their biggest advantage is the easy installation and the easy dismantling.

Flooring

The attractive, easy-to-clean surface is finally produced by a corresponding top coating. The choice is:

Mineral coverings: tiles, natural stone slabs, polygon slabs
Art flooring : cast acrylic, PVC, carpet, laminate
Wooden flooring: decorative chipboard, real wood parquet, floorboards

The selection of toppings is huge. Prices range from 5 euros to 500 euros per square meter . If it has to be expected economically, the most money can still be saved by choosing an inexpensive, yet appealing and functional surface. However, the floor should always be planned in a coherent concept. It makes no sense to spend a lot of money on underfloor heating and then to insulate them with thick plank boards or a centimeter thick acrylic layer. This only wastes energy and thus a lot of money. Good advice can be obtained from the local energy consultant.

Planning saves costs

In summary, the question of what exactly costs one square meter of floor can hardly be answered. It always depends on the specific situation and the wishes of the individual how expensive a floor should be in total. Therefore, a reduction in technical qualities should only be made deliberately. It is better and more sustainable not to settle for a few years with the dream-desired cover, but not to have saved it in terms of comfort and safety of the floor. Nothing is easier to replace on a floor covering than the topmost cover layer. If you have to pay attention to the budget, our recommendation is therefore: The full comfort, including underfloor heating with sustainable insulation, also offers a floor, which is covered with a cheap PVC. If the budget allows it again, the PVC can be replaced by a high quality parquet or an attractive, mineral coating. This gives you, albeit a little later, the perfect floor for your living space.

However, the recommendation "As little styrofoam as possible" can not be repeated often enough. The additional costs of alternative thermal and impact sound insulation are more than doubled again during dismantling. Now wisely rely on wood fiber or mineral wool plates and to dispense with the PU foams is the order of the day for a sustainable, healthy and safe construction.