If we are talking about the floors installed in the "floating" system, the properties, parameters and comfort of use are determined by both the board (panel) and what it is placed on. Thanks to the right foundation, we provide a kind of "foundation" between the panels and the ground. The underlay not only protects the floor, but also improves its performance. Even high-quality flooring can only show all its advantages if together with the underlay function consistently as part of the flooring system.
Must have with the underlay
The underlay must take over important functions because it is the basis for professional floor installation, because:
• levels out any point unevenness in the floor, which relieves the locking joint of the panels;
• protects the floor against daily stress when walking or, for example, from being hit by falling objects, but also against the constant stress caused by heavy furniture.
• provides effective insulation against moisture,
• mutes the room - reduces the sounds of footsteps in the room and provides additional soundproofing when sound penetrates the subfloor
• good underlay reduces the cost of underfloor heating.
Remember that when you buy even the best and most expensive panels, you will not get the desired effect if you do not take care of the appropriate underlay and follow the rules contained in the panel manufacturers' instructions. Well-installed panels and a good underlay guarantee the comfort of using the floor on a daily basis.
Take care of the subfloor under the underlay
Installation of the floor can begin only after all construction and finishing works are completed. The room must be dry and have an efficient ventilation system. The temperature in the room should be in a range of 18-23 degrees Celsius, and the substrate should also have similar temperature. The floor must be laid on a stable and levelled surface, the deviation of which may not exceed 2 mm by 200 cm in length. The subfloor for laminate flooring must be dry and clean. As wood and laminates are very sensitive to moisture, it is worth checking the humidity of the substrate, in the case of humidity greater than 2%, the manufacturer will not accept the guarantee.
The requirement of majority of panel manufacturers is to provide a vapor barrier, i.e. permanent protection against moisture from the ground. Failure to use a vapor barrier is a common reason for rejecting the warranty.
A special foil with a parameter SD> 75 m can be a vapor barrier (this parameter replaced the foil thickness, which was previously given as a quality indicator). Do not use foil that is not intended for this purpose, e.g. painting foils.
On the prepared substrate, a vapor barrier foil should be spread over an overlap of 20-30 cm and glued with a moisture-resistant tape. The foil must be turned onto the walls to a height of 3-4 cm.
A faster and more reliable alternative is the use of underlays with an integrated 2-in-1 vapor barrier foil or 3-in-1 underlays, which, in addition to the integrated vapor barrier foil, also have a self-adhesive layer that makes it easier to connect the underlay.
Finally, let's choose an underlay for the floor
The entire range of underlays can be divided into two groups:
- underlays for laminated panels and a multi-layered board,
- underlays for vinyl panels.
Both groups of underlays must of course meet the requirements of the European standard EN 16354, which strictly defines what tests and parameters the product must meet to protect our floors and to be called an underlay.
The division into two groups results from the specific requirements that are imposed on underlays for various types of flooring. Vinyl panels mounted with a specially milled lock, the so-called "Click" are products with a small thickness, usually from 4 to 6 mm. Precisely milled locks in these panels require special protection - therefore the static pressure that the underlay under the panels must take on itself should be at least 200 kPa, and the value recommended by manufacturers of vinyl panels is as much as 400 kPa. For comparison, classic laminate floor require a minimum value of 10 kPa - this is as much as 20 times less.
Before instaling the floor, an underlay suitable for the room and its purpose should be used. The underlay improves the comfort of using the floor and increases its durability. Additionally can also performs a specific function. The underlay can insulate from cold or, on the contrary, conduct heat well if we want to use underfloor heating. Underlays in different degrees also mute the room. The features and functionality of the underlay largely depend on the material from which they are made. The following are available on the market:
Polyurethane-mineral underlays (PUM), the so-called Multiprotec’s or quartz mats - top-shelf underlays ensure the best soundproofing of the room. They have a very high resistance to pressure, thanks to which they protect the floor and ensure its durability. Thanks to a very low coefficient of thermal resistance, they are perfect for underfloor heating. Polyurethane underlays allow you to save up to EUR 150-200 in one heating season. The most popular underlay of this type is MULTIPROTEC 1000.
Extruded polystyrene (XPS) underlays - ideal for levelling minor imperfections in the subfloor. Such underlays can be up to 6 mm thick and due to the high level of thermal resistance they are the best thermal insulator among underlays (they work well over unheated rooms). Despite their high flexibility, they retain the durability of the panels thanks to their very good resistance to loads. The XPS underlay comes in all forms: traditional board, roll and the fastest to install accordion form. They are also extremely light, which facilitates transport and assembly, especially for beginners.
Underlays made of high-density polyethylene (PEHD) - underlays of this type are suitable for underfloor heating, also fulfil their role when it comes to soundproofing the room in which they are installed.
Traditional underlays – established on the market for the longest time, such as cork, which is a weak soundproofing material, and with time it crumbles, which may not provide full protection. The so-called eco-board, which can additionally reveal some dust and dirt, and despite its high weight and hardness, is not resistant to high load. This product absorbs moisture, exposing the panels to damage even with the tiniest amount of water. Additionally, it is not suitable for underfloor heating. Commonly known PE foam or corrugated cardboard, still found in some stores, are not suitable as an underfloor for floor panels and in accordance with the EN 16354 standard should not be used any more under any floor covering. Such material causes rapid degradation of the panels and virtually eliminates the recognition of the guarantee by the panel manufacturer. Underlays are sold in various forms and packages. The most popular on the market are boards, seemingly easy to lay, but due to the need to connect them with tape, they become time-consuming for larger surfaces. The second most common form is a roll, which, thanks to the possibility of unfolding, is well suited to laying in larger rooms. A novelty on the market is a fan folded-shaped underlay. The possibility of gradual, precise laying makes it the easiest and fastest way to install the underlay. It is laid even 5 times faster than a traditional board. The fan folded underlay is called a new generation of board.
If we already know the division according to the type of floor and we already know the technology in which the underlays are produced, it is time to take care of the additional requirements for underlay.
Is the underlay you are looking for helping us to reduce the noices the room, or maybe we have underfloor heating and want to use it in the most effective way, or vice versa, we have a cold room below and we want to isolate ourselves from it. Knowing our needs, we can pack a suitable underlay into the trolley.
First, sound dampening
This is a parameter that should be considered when choosing laminate flooring. First of all, due to its structure, laminate panels are much louder than other types of floors.
While it is not possible to completely eliminate the noise of using the floor, it can be significantly reduced with a suitable underlay.
The sound reduction is given in the case of:
- walking steps sound (RWS - Reflected Walking Sound) in percent (%), - applies to laminated panels
- in the case of attenuation of noise transmission to lower rooms (IS - Impact Sound) in decibels (dB), for laminate, vinyl and multi-layered panels.
What does it mean? The noise reduction of 10 dB corresponds to a 50% mute for the human ear. Underlays from the PUM series, i.e. products from the Multiprotec range, perfectly absorb sound waves and mute the floor. The difference in using the floor is colossal, the knocking effect is almost completely eliminated.
Protect the floor
When buying a new floor, we do not want to have problems with it for at least a few years. The most fragile and sensitive elements of the panels are their connections, called locks. The key role in the protection of the floor is played by an appropriate underlay, and the most important parameters describing the underlay's strength are compressive strength (CS) and dynamic load (DL).
For rooms with floors exposed to high traffic - such as corridors, waiting rooms or rooms where we often move heavy objects - e.g. armchair on wheels, choose an underlay with the highest CS and DL parameters. The higher the "CS" and "DL" values, the better the underlay protects the click-lock system against gaps or breakages. With increased requirements, the "CS" value should be at least 60 kPa for multi-layered boards and laminated panels and 400 kPa for vinyl click flooring.
Do not pay extra for underfloor heating
The decision on the type of flooring is made at an early stage of the investment. The thermal resistance of the subfloor should be taken into account when choosing a floor. The lower the thermal resistance value of the system, the faster the room heats up and the lower the heating bills.
It has been proven that the thermal resistance of the floor system (floor covering + underlay) should not exceed 0.15 m2K / W - (EN 16354 standard and DIN EN 1264 guidelines).
To determine the thermal insulation of the floor system, add the value of the thermal resistance of the floor and the underlay. For example: an 8 mm thick laminate floor has a thermal resistance of approx. 0.08 m2K / W. For such a floor, we should use an underlay with a thermal resistance below 0.07 m2K / W. Obviously, the lower the thermal resistance, the greater the savings on heating.
The standard 8 mm panel and the popular 5 mm eco-board underlay are a loss of almost a EUR 200 a year. Multiprotec underlays are several times better, thanks to a very low thermal resistance.
How to look for a underlay in the store?
If we have already come to a store where the choice is very large and the shop assistant is busy - let's use the simplest solution - the label on the product. Many European DIY chains have products from the SECURA AQUASTOP SMART series by ARBITON. These underlays contain an integrated vapor barrier foil and adhesive tape, thanks to which they not only speed up installation, but also provide 100% protection of the floor. Colourful cardboard boxes and intuitive communication on the label is a way to quickly and correctly find the product you are interested in. Large, legible icons will tell us what features the product has. The MADE EU mark is also important, which in this case means the highest quality.