Glossary: Laminate Dictionary

Abrasion classes

Laminate flooring's resistance to abrasion is given as its abrasion class (AC 1, AC 2, ... according to DIN EN 13329).

The abrasion class is determined by clamping a test piece in a testing device and placing wheels (friction wheels) covered with emery paper on the test piece. The test piece is checked for abrasion after every 100 revolutions. The emery paper on the friction wheels is changed every 200 revolutions. The initial abrasion point (IP) is the point at which clearly detectable wearing through of the decorative print occurs for the first time.

Acclimatisation

Krono Original^® laminate is more than 90 percent made of wood-based material (substrate, mostly HDF) and therefore has the typical material properties of wood. Among other things, this means that the material adapts to the surrounding humidity. Moisture is absorbed or discharged by the wood-based material depending on the humidity of the room. This can lead to distortions such as swelling or shrinkage.

In order to adapt the material to the room's climate before laying, you should store the laminate in the room it is to be subsequently laid in for around 48 hours. If this acclimatisation of the laminate is not allowed for (for example, if the laminate is transported directly from the "dry" DIY store into a still "damp" new building and is laid immediately), among other things, joints can form and distortion can occur.

Storage in heated, draught-free rooms with a relative humidity of less than 75 percent and an air temperature of around 18 degrees Celsius is ideal.

AC

see Abrasion Classes

B1

Symbol in accordance with DIN 4076 Part 5 for flame-resistant building materials. The DIN also differentiates between B2 for normally flammable and B3 for highly flammable building materials.

Krono Original^® laminates conform to class B1.

Backing

The backing papers consist of resin-impregnated papers and are primarily used on the underside of the laminate panels to balance the stresses between the overlay, decor paper and if applicable the soda kraft paper on the top.
If a substrate were to be coated with laminate on one side only the substrate would bend due to the one-sided absorption of moisture from underneath – this is also called "dishing".

Cleaning and cleaning agents

As it is difficult for dirt particles to settle on the closed and resistant laminate surface, in most cases it is sufficient to clean the floor with a wrung-out moist cloth and a simple soap-based wipe off product. Cleaning with too much moisture can cause swelling of the substrate. When choosing a laminate cleaner, ensure it does not contain any waxes or oils. Oils and waxes cannot (as in a wood surface) penetrate the closed laminate surface and therefore lie on top of the laminate as a greasy film. This film causes wipe smears during cleaning and footmarks when the floor is walked on.

Click laminates

are glue-free interlocking systems which provide important advantages for the layer of the laminate flooring compared to conventional, simple glued joints. Special profiling in the tongue and groove area enables two panels to be fitted together without using glue. The easy laying and immediate use of the laid flooring enable time savings of around 50 percent. The flooring can be reused. This means that in certain situations such as a move or repairs, it can be removed and can be relaid elsewhere. The precisely fitting profiling also prevents the formation of joints between the panels when they are laid, as it is not possible for the tongue to slide out of the groove.

Contaminants

The quantities of solvents and formaldehyde found in laminates are so small that laminate is classified as low-emission or emission free (contaminant free) according to E1.

Décor paper

Decor papers are printed paper; these are mostly covered with coating materials printed with wood structure imitations such as beech or maple or are even plain coloured. The printed papers are impregnated with melamine resin and are pressed, together with the overlay, onto the top of the substrate under heat and pressure.

DIN EN 13329

This European standard specifies the characteristics, requirements and test methods for laminate floorings. It contains a classification system for service classes with practical requirements for certain areas of use and performance classes. It is used to point out the areas in which laminate floorings can be satisfactorily used.

The following requirements, amongst other things, are defined in the standard:

• Dimensional changes following changes in the relative air humidity
• Level differences between joined elements
• Joint openings between joined elements
• Perpendicularity of the element
• Lightfastness
• Surface soundness – Appendix see Service Classes

In addition, it enables consumers to make an informed choice.

DPL (direct pressed laminate)

DPL laminate flooring is the most common type of laminate flooring and is available in service classes 21 - 32. DPL floorings have the following build-up: Overlay, decor paper, substrate and backing. During manufacture these four laminate flooring components are pressed together under pressure and heat to form starter panels (basic panels) and after a cooling phase are forwarded to the profiling process. Here the panels are cut to the required panel size and are profiled. DPL floorings are produced with the simple tongue and groove joint or with the Click system (sometimes also called the Loc system).

DPL laminate flooring: the direct lamination

The direct lamination - all four components are pressed in a single step

1. Overlay:
resistant special coating, hard-wearing, easy-care surface
2. Decor paper: Visual effect through decor
3. HDF: Wooden core substrate, the heart of the laminate flooring
4. Backing layer: moisture retarding backing for dimensional stabilisation

E1

is the symbol for emission classes. The emission classes designate the wood-based materials according to the amount of formaldehyde they emit. A differentiation is made between classes E1, E2 and E3; whereby class E1 emits the smallest amount of contaminant. The test room is decisive for the classification. Here a test piece is "washed around" with air at a constant temperature for a specific time. The formaldehyde emitted is collected in distilled water and is measured. The formaldehyde content in the air is measured parts per million (ppm). The allowable room contamination may not exceed a value of 0.1 ppm. Standard laminates have such a low percentage of contaminants that they are deemed to be "contaminant free".

see Formaldehyde

Krono Original^® laminates conform to emission class E1.

Electrostatic charge

Under certain circumstances the electric charge carriers, the electrons, jump from objects to people – and therefore give us a slight electric shock. These electrons are caused by separating processes of electrically non-conductive materials. The causes can be a dirty surface of a laminate flooring, too low humidity (especially during the winter months) or electrically insulating materials such as shoe soles and clothing. Counteracting measures include the use of an air humidifier, electrically conductive chairs, special cleaning agents containing the highest possible proportion of surfactants, wearing electrically conductive footwear as well as clothing with low synthetic fibre content.

Expansion joints

have to be allowed for when laying Krono Original^® laminate floorings if the area to be laid is more than eight metres lengthwise or in width. This is necessary as the floor's typical swelling and shrinkage performance is impaired in a large area, due to its high self-weight and the load of the furniture placed on it.

Examples of uses: see Expansion Profiles

Formaldehyde

is a colourless, pungent smelling gas. Formaldehyde is an important raw material for the manufacture of resins, which are used as adhesives in the production of wood-based materials such as laminate floorings or particleboards. Formaldehyde irritates the eyes, mucous membranes and respiratory tracts. The perception limit lies between 0.2 and 1.0 ppm (parts per million). Due to increasingly stricter legal requirements, the proportion of resins containing formaldehyde used in the manufacture of laminate has been limited to such an extent that the floorings are classified "formaldehyde-free".

see E1

Glues

Glues are adhesives made of synthetic, animal or vegetable raw materials with water as the solvent and dispersant. It is advisable to use D3 glue (alternatively D4) for gluing the tongue and groove joint of laminate panels. D3 is a standardised abbreviation and stands for the suitability of glue for indoor use with frequent, short-term effect of flowing water or condensation and/or long-term high humidity. Class D1 and D2 glues on the other hand are not suitable for gluing laminate.

Important: Glue is applied to the upper side of the tongue only!

HDF (high density fibreboard)

This is a wood-based panel made from wooden fibres. HDF panels are mainly used as the substrate for laminate floorings. They have a very homogeneous structure and closed surfaces. Therefore, HDF panels can be directly laminated, printed, veneered or even painted or varnished. Compared to particleboards and even MDF boards, they have a higher density and therefore better bending strength and transverse tensile strength. Their swelling properties are also better than those of particleboards. Visually, high density fibreboards are very similar to MDF panels.

HPL (high pressure laminate)

is the "Mercedes" among laminate floorings. Due to its extremely resistant surface it is available in the service classes 32 and 33. HPL floorings are made-up of overlay, decor paper, several soda kraft papers, the substrate and a backing. These components are pressed together under heat and pressure in two stages. In the first stage the overlay, decor paper and soda kraft papers are pressed together to form a layer (HPL). In the second stage the HPL layer is then glued onto the substrate, whereby, for reasons of stress symmetry, a backing is attached to the back of the element. Following a cooling phase the panels are added to a profiling line where they are cut to the required panel size and are profiled. HPL floorings are produced with the simple tongue and groove joint as well as with the Click or Loc system.

HPL laminate flooring: the high-pressure laminate
Three-stage process - high-pressure laminate production

• 1 - Overlay
• 2 - Decor paper
• 3 - Core layers
• 4 - Laminate layer 0.6 millimetre hard-wearing, easy-care surface
• 5 - HDF wooden core substrate, the heart of the laminate flooring
• 6 - Backing layer laminate moisture retarding backing for dimensional stabilisation

1st operation

• 2 layers of overlay
• 1 layer of decor paper
• 3 core layers

are pressed together under pressure to form a decor laminate

2nd operation

• 1 layer backing paper
• 3 core layers

are pressed together under pressure to form a backing laminate.

3rd operation

• Decor laminate
• Backing laminate

are pressed together to form high-pressure laminate.

Impact sound

also known as transmitted sound, is a special form of structure-borne sound. It is caused by walking on the floor; it is transferred by the flanking walls and ceiling/floor and is emitted as airborne sound. The noise is measured in decibels (dB). Impact sound insulation is laid under the laminate during laying to counteract impact sound. The flooring build-up is then as described in the sketch. Different materials are used for the impact sound insulation: 2 millimetre thick "Noppa" (slubbed) foam sheeting, cork mats and tiles, felt sheeting and tiles or the "Sound Absorb System" from Krono Original.

Impregnation of laminate

Impregnation of the substrate against moisture is very important, especially for the glueless click connection. This impregnation is achieved by increasing the resin fractions in the manufacture of the substrate (HDF) as well as by adding water-repellent agents such as waxes or paraffin. Additional sealing of the joints between two laminate elements can be achieved during laying by applying glue or Clickguard.

In conventional glued joints the glue applied has the double function of gluing and impregnation. Impregnation after laying the laminate flooring is not helpful: The impregnate enables film-forming substances such as waxes to reach the surface of the laminate where they are very difficult to remove again. One consequence of this is the formation of striations and streaks.

IP

see Abrasion Classes

Laminate service classes

can be used by consumers as a basis for comparison and are used by manufacturers to classify their products. The laminates are classified in the service classes according to their resistance: abrasion, impact resistance, lightfastness. The service classes give a recommendation for the area (for example domestic or commercial areas such as hotel rooms, offices) for which a respective classified laminate is suitable. The classification of laminates is based on DIN EN 13329.

The following classification according to area of use, intensity of use, usage and examples of use apply to the labelling of the performance classes by means of pictograms:

Performance class	Area of use	Intensity of use	Description of use	Examples of use
	Domestic Area for private use	moderate	temporary use	Bedrooms Spare bedrooms
	Domestic Area for private use	normal	normal use	Living room Dining room Interior hallways
	Domestic Area for private use	high	intensive, increased use	Staircases Entrance hallways Kitchens
	Commercial (building) Areas for public and commercial use	moderate	temporary use	Hotel rooms Conference rooms Small offices
	Commercial (building) Areas for public and commercial use	normal	normal use	Nurcery Offices, Waiting rooms, Hotel lobbies, Boutiques
	Commercial (building) Areas for public and commercial use	high	intensive, increased use	Corridors, Open plan offices, Department stores, Classrooms

Laying direction

The laying direction is a matter of taste. We recommend laying the floor lengthwise to the main light source and transverse to the direction of movement (walking). It is often not possible to adhere to this recommendation as, for example, the door and window are located opposite each other. Here a decision must then be made based on taste. Laminate can also be laid on the floor diagonally or in different directions if appropriate transition profiles are used. If the sub-floor is made of planks, the laminate panels must be laid at right-angles to the lengthwise direction of the planks.

Overlay

see Surface

PE sheeting

see Vapour Barrier

Sound Absorb System (S.A.S.)

based on a completely new type of technology. This high-tech coating is only 0.3 millimetres thick and consists of a special thermoplastic which converts part of the sound energy into thermal energy. The Sound Absorbed System reduces perceptible walking noises by more than 10 decibels – which equates to a 50 percent reflected sound reduction. Further advantages are its optimum thermal conductivity which is good for laying on underfloor heating systems. No other impact sound underlays such as “noppa" (slubbed) foam are required. In addition, the S.A.S. coating is environmentally friendly.

Skirting boards or baseboards

are the optimum solution for a harmonious crossover from (or finish of) the laminate flooring to the wall. Apart from the visual effect, the skirting board also covers the important spacing from the wall. Skirting boards are available in decors matching the floorings as well as with various profiles and sizes. Skirting boards are fixed to the wall with screws, nails, gluing or by means of fixing clips. Clips are dowelled into the wall at approx 30 centimetre spacings and the moulding is simply pressed onto the clips. The clip connection enables the moulding to be easily fitted and removed several times without damaging the wall - for example for wallpapering or painting the wall.

Sub-floor

The properties of the sub-floor must enable the laminate flooring to be laid according to the manufacturer's instructions. Suitable sub-floors for laying laminate on include, among other things, mineral sub-floors such as screed, concrete, asphalt, wood particleboard constructions, wooden floorboards or old sub-floors with existing hard floorings such as stone, ceramic and PVC.

Sub-floor unevenness

The evenness of the sub-floor is important for the laying of laminate floorings. Sub-floors with differences in the surface of more than three millimetres over a metre must be sanded down or filled/smoothed (with filler) - according to DIN 18202. The evenness of the sub-floor is best determined with a floating rule or with a long spirit level.

Sub-floor strength

It is necessary for the sub-floor to be as strong and firm as possible for the laying of laminate. Before laying the laminate, ensure that the sub-floor does not spring or bounce and cannot be pushed in when a load is applied. This happens if you want to lay your laminate on a soft surface. Carpeting is not a suitable sub-floor on which to lay laminate.

Sub-floor moisture

Especially with mineral sub-floors such as screed (cement screed, anhydrite screed) or even a sub-floor concealed with a wearing surface (natural stone, ceramic tiles or slabs, plastic), rising damp must always be expected. You can use a "CM Measuring Device" to check the moisture content of the named mineral sub-floors.

To ensure possibly rising damp cannot penetrate the laminate flooring it is necessary to lay sheeting directly on the sub-floor as a vapour barrier. You do not have to lay sheeting on sub-floors made of wood or wood-based boards such as planks or particleboards.

Substrates

are all types of wood-based panels which carry surfacing materials. Surfacing materials are, for example, laminates and veneers. Six to eight millimetre thick HDF boards are mainly used in the manufacture of laminates. The substrates for Click laminates are made with a particularly low swelling capacity by adding a higher proportion of glue when pressing the board. The engineering properties of particle boards such as compressive strength and allowable impact loads are substantially lower than those of HDF boards as is the easy of laying and they will disappear from the market as a substrate material in the long-term.

Surface

Unlike parquet and veneered floorings, the surface of laminate floorings does not consist of a varnish, oil or wax coat applied to the wood. Laminate surfaces have a thin top layer made of synthetic resin impregnated paper (mostly melamine resin), which is also called an "overlay". The overlay together with the decor paper is pressed onto a substrate (HDF).

During pressing the melamine resin fuses the individually coated paper layers under the action of heat and pressure to form a mechanically strong surface.

Thermal conductivity λ

The thermal conductivity (previously "coefficient of thermal conductivity) gives the quantity of heat in λ transported per second along a length of one square metre at a temperature difference of one degree. The λ value of building materials is required for calculating the thermal insulation of structural elements. The λ values of particleboards or fibreboards (substrates of laminate panels) are lower than those of solid wood of the same density or other building materials. Due to their good thermal conductivity, laminate floorings are ideally suited for laying on hot water underfloor heating systems.

see Underfloor heating

Tools

It is important to have suitable tools to hand to ensure easy, problem-free laying of laminate. You will need a laying set consisting of a tapping block, drawbar, spacer wedges and a paint scraper/putty knife. Furthermore, you will need a hammer, a suitable saw (optimally a keyhole saw), glue, a folding rule or measuring tape, angle/T-square, a pencil, a drill for the skirting boards, adhesive tape and a carpet knife or cutter for the PE foil and the impact sound insulation.

Underfloor heating

Due to its high material density, laminate is ideally suited for laying on hot water heating systems. Laminate flooring is a very good thermal conductor. As hot water underfloor heating systems lie in a screed bed, it is important to perform a moisture test (see Screed). In addition, before laying the laminate flooring, the system should be heated up according to a specific procedure and the results recorded. When laying laminate on underfloor heating, polyethylene sheeting is laid first. The transmitted sound underlay chosen should be a material with high material density – for example, non-woven or unvulcanised natural rubber (caoutchouc). But these materials have a decisive disadvantage: Their material thickness of around three to eight millimetres. The best solution here is provided by laminate with S.A.S. technology: It combines an extremely good thermal conductivity with only 0.3 millimetre material thickness.

Important: Krono Original^® laminate floorings are not suitable for laying on electric underfloor heating systems!

Vapour retarder / vapour barrier

Vapour retarders or barriers are plastic sheetings (mostly polyethylene = PE foil), which is intended to prevent moisture from penetrating through the sub-floor, for example screed, into the laminate flooring. Vapour barriers only have to be laid on mineral sub-floors such as screed, concrete or asphalt, as under certain climatic conditions water vapour can collect in the floor area as condensate and can cause structural damage. Viewed from the warmer side, the vapour barrier must lie in front of the layer at risk from condensation (i.e. under the laminate). The vapour barrier is laid as a "trough" and extends around ten centimetres vertically up the surrounding wall. The sheets are laid next to each other with around 20 centimetre overlap and are fixed with adhesive tape.

see also Laying Instructions

Wall clearance

The distance between the laid laminate flooring and the wall is one of the most important points to be noted when laying a laminate. The distance should be between 12 and 15 millimetres and is fixed during laying by the spacer wedges. Laminate is a wood-based material which swells under the influence of moisture and shrinks in a dry environment. It is therefore important to give the laminate flooring room to "work". This prevents subsequent damage due to swelling. Damage that can occur includes, among other things,: Open joints, swelling parallel to the lengthwise joint, longitudinal contraction (buckling) in the joints area with peeling and flaking decor, rises in the floor ("hills").

Wet rooms

are for example, bathrooms or sauna areas. Because of their typical material properties, laminate floorings are not suitable for these rooms with their extremely high moisture content.

Wood-based material

is a generic term for products made by breaking down wood into chips (particles) or fibres and them joining them together again (mostly by means of pressing) with the addition of adhesive or resins. Wood-based materials are, for example, particleboards, medium density fibreboards (MDF), high density fibreboards (HDF) or plywood.