How To Install Laminate Flooring Properly in Old and New Constructions, Uneven Floors
Layers of Laminate Flooring Board
Types of Subfloors Suitable for Laminate Flooring
How To Fix an Uneven Floor
Subfloor Moisture Content Management
Preparing the Wood/Laminate Floor Panels for Installation: Acclimatization
Step by Step Installation
Subfloor Floor Layout, Transition Profiles and More
Laminate flooring is a multi-layered single board with tongue and groove edges for fitting the boards together. The boards are laid on a suitable subfloor using the floating floor method whereby the tongue-and-grooved planks are not fixed to the subfloor by any means. Apparently, no glue or nails are used to fix the laminate board in place, so this is not a permanent installation, but a floating floor which can be easily removed during renovations. The floating floor system is a modern method of installing laminated floor boards which is widely used nowadays, being preferred by many homeowners due to its ease of installation, removal and capability of being re-used in new works. Glued and nailed laminate floors are no longer popular.
Other advantages of laminate flooring is that it is cheaper than natural hardwood floors, although vinyl floor covering is a little bit cheaper than laminated board floor. Hardwood floors are highly valued because of their durability, natural wooden texture and appearance as well as their ability to be sanded and refinished. Laminate flooring is a cheaper alternative to achieving a hardwood appearance due to its decorative paper layer that can be imprinted with a wide variety of wood appearances. However, unlike natural wood which can be easily scratched, blemished, dented and stained by spills, the surface layer of laminated floor boards is made of melamine resin which is not just stain-proof, but also highly resistant to abrasion and wear.
Laminate flooring has its disadvantages and challenges. While it looks like one of the easiest floors to install, the conditions in which the floor is installed as well as the fixing methods will make all the difference between a disastrous and top-notch installation. Installing a floating floor requires careful preparation of the subfloor as well as making allowances and adjustments for the environment/conditions and properties of the floor. The most common problems affecting laminate board floors is poor installation, lack of preparation and planning leading to buckling, micro-gapping between boards, expansion bumps, uneven floor, moisture damage and footstep impact plank noise. Also, laminate flooring is not as durable as hardwood and it tends to be too slippery. Tests by the CPSC have found that laminate flooring can release toxic amounts of formaldehyde in the air depending on the type of floor, its components and manufacturing process. High levels of formaldehyde can cause health issues such as cancer, skin rash, itching and asthmatic allergies.
Layers of Laminate Flooring Board
At this point, you should be wondering what the layers of laminate flooring are made of. As mentioned previously, laminate flooring is a plank, board or panel with layers bonded and fused together into a single board with superior qualities. The board is factory-made, manufactured by pressing and fusing together 4 or 5 layers of materials, each of which has specific characteristics and properties which are required to make a super composite board known as a laminate.
The 4 layers in a laminate flooring board are:
- The wear layer also known as the overlay (transparent melamine resin or aluminium oxide coating)
- The decorative cellulose or kraft paper layer
- The HDF core (high density fibreboard) – 12.5mm thick
- The backing layer (stabilizing layer) – 3 to 5mm thick melamine backing
During the manufacturing process, glue is applied on the layers between rollers before they are stacked on top of each other in the production line. The stacked layers are then fed into a pressing machine where they are fused at high temperatures and pressure for about 25 seconds. The temperature and pressure in the press ranges between 170 to 210 celsius and 18 to 23 MPa respectively.
The bottom layer is the backing layer also known by different names such as backer board, balancing sheet or stabilizing layer. The backing layer helps to stabilize, straighten and balance the HDF core board. It is made of a thin melamine board. The backing layer is also highly resistant to moisture absorption and percolation.
On top of the backing layer, the HDF core is placed. The core board is the source of the plank’s stability, durability and strength, with its thickness being the determining factor for these properties. The thicker the core, the greater its durability and strength, and the more it resembles the qualities of a hardwood floor, with less hollow feel and noise.
On top of the HDF core, a layer of decorative paper with high resolution imprinted textures and patterns is laid. Laminate decorative papers are made of cellulose or kraft paper which is impregnated with resin. There are two types of decorative papers, plain colour and textured print papers. Both have different industrial treatment processes. Plain colour kraft papers are first impregnated with phenolic resin, then cured and dried. To impart durability, the cured paper undergoes a second stage in the production line whereby it’s impregnated with melamine resin, then cured and dried. It is then cut into sheets.
Textured laminate papers are not impregnated with resin. Instead, the kraft paper is cut into sheets which are stacked on top of each other, over which an overlay (transparent wear layer) is laid. The top side of the kraft paper will be the decorative layer. Alternatively, plain colour paper impregnated with resin manufactured earlier on, can be stacked under the decorative layer. Textured plates are then laid onto the decorative layer. The stacked layers are then fed into a press to be compressed and bonded at extremely high temperatures and pressure. The textured plates impart their patterns to the decorative layer during heating. The laminates are then cured with hot air and cooled.
Before laminated floor planks are laid on the subfloor, the contractor must install some underlayment on the subfloor. The function of underlayment is to cushion the planks, as well as being an acoustic insulator to improve the noise absorption properties of the floor. Underlayment can also function as a thermal and moisture barrier.
You should install underlayment when the laminate flooring doesn’t come with an underlayment attached. A cross-linked and closed-cell polyethylene foam with a moisture-resistant polyethylene film is often used as underlayment.
On concrete subfloors, floor laminates with attached underlayment will not be enough. You need an extra separate moisture barrier sheeting (e.g. 0.127mm thick polyethylene film) that should be laid on the subfloor before installing the laminated floor boards.
Types of Subfloors Suitable for Laminate Flooring
Laminate flooring can be installed on many types of subfloors but these should be limited to the following for best results:
- Concrete subfloors with granolithic screeds or topping
- Concrete subfloors with earthenware or stoneware surface covering e.g. ceramic, porcelain, stone, granite, terrazzo tiles, quartz and cement tiles etc.
- Concrete subfloors with thin flat covering e.g. vinyl tiles or sheets, linoleum, epoxy resin floors.
- Structural timber subfloors and decks with sheet covering or floor boards
- Structural steel subfloors with sheet covering or floor boards
Avoid installing laminate flooring on the following types of floors to prevent issues and problems:
- Floors with carpets (most carpets are not suitable, especially thick or fluffy carpets). In exceptional cases, laminate floor boards may be installed on thin carpet (up to 6.35mm thick) firmly glued on wood subfloors. However, it’s not advised to install laminate flooring on most types of carpets or carpets on concrete subfloor.
- Floors with padding
- Textile flooring or woven fabric floors
- Floors with loose and poorly glued sheet covering (e.g. vinyl tiles)
- Floors with more than one layer of sheet covering (e.g. vinyl)
- Wet rooms such as bathroom, shower cubicle, steam laundry, cold rooms, sumps and saunas.
- Wood subfloor over concrete e.g. plywood panels on framing
- Wood flooring on concrete e.g. hardwood tiles
- Floors with undersurface floor drains and sumps.
- Floors with surface or thinly covered undersurface floor heating (e.g. underfloor heating mat). Installation on heated floors is only permissible when the heat conductors (cable mat) or warm water hydronic pipes are embedded in concrete or laid on wood subfloor, but the temperature should not exceed the maximum required value (28 degrees Celsius.)
- Any floor or surface that is not a stable or firm substrate for laminate flooring to rest or be attached on.
Concrete subfloors with granolithic screeds or topping
A concrete slab is susceptible to moisture penetration due to its porous structure (voids) which allows uptake of water from the soil through capillary action. Ground and atmospheric moisture in the form of water vapour (mist, fog) is also attracted to the hygroscopic surface of concrete on which the water vapour can condense. As a code of practice, when installing laminate flooring on concrete screeds, you should install a moisture barrier (0.2mm thick polyethylene vapour barrier) on the concrete surface to prevent moisture from penetrating and affecting the laminate boards.
When the laminate boards come with moisture-resistant underlayment attached, a thinner moisture barrier (0.127mm thick polyethylene film) must be used.
Underlayment for floating wooden floors comes in different types, brands and specifications. There is a brand of underlayment with multiple functions and properties, acting as a cushion (shock absorber), moisture barrier, thermal and acoustic insulator. This type of sheeting is usually thicker than mono-functional underlay (at least 75mm thick). It can be used as a moisture barrier on granolithic concrete floors instead of the 0.2mm polyethylene damp-roof membrane. When purchasing underlayment, you must find out the functional specifications from the manufacturer or supplier.
Concrete subfloors with earthenware or stoneware covering e.g. ceramic, porcelain, stone, granite, terrazzo tiles, quartz and cement tiles etc.
This type of floor cover is heavy high density material, well settled and firmly fixed on concrete, so it’s usually resistant to buckling and warping. However, it’s vulnerable to moisture penetration, so you should install a 0.2mm thick polyethylene vapour barrier before laying your laminate flooring. Make sure that cracks , broken tiles and gaps are fixed and filled before installing a moisture barrier. Any loose tiles should be replaced and firmly fixed to the concrete with adhesive or mortar.
Concrete subfloors with thin flat covering e.g. vinyl tiles or sheets, linoleum, epoxy resin floors.
This type of floor cover is made of plastic and various types of synthetic resins such as vinyl ester, polyester and epoxy. The floor covering is usually installed as a sheet glued on the concrete surface or applied as a viscous thermosetting coating. Plastic and synthetic resins have inherent water-resisting qualities which makes them impervious to water penetration, so a commercial moisture barrier such as polyethylene might not be needed prior to installing laminate flooring. But this depends on the condition of the floor. You may need to remove the floor sheeting and scrape off the glue and coating if it’s in bad condition.
Structural timber subfloors and decks with sheet covering or floor boards
Laminate flooring can be installed on suspended wood subfloors and decks, but not on wood flooring fixed on concrete. Structural timber subfloors must be suspended at a minimum height of 450mm above ground level to allow circulation of air. A moisture barrier is not required over a wood subfloor as this tends to impede proper ventilation of the subfloor space. Air must be able to move in and out of the crawl space freely to keep the space dry. Ventilation helps to keep the moisture content of wood subfloor from exceeding the maximum value (12%).
In case you want to install a damp-proof membrane or vapour barrier over a wood subfloor, you should take measures to mitigate the effects of sealing the floor which often leads to reduced ventilation. To allow adequate ventilation, install perforated floor boards with airflow grills as well as ventilated skirting around the floor. Air vent openings, suitably spaced around the subfloor walls should be made, and to speed up the circulation of air, a fan and air extractor system must be installed under the floor.
How To Install Laminate Flooring Properly
Site Conditions and Preparation
Before anything else you have to measure the size of the room that you are going to install laminate flooring. Measure the length and width of the room to find its floor area. When ordering materials from your laminate floor supplier, they will need the floor area and its plan shape to determine the quantity of planks required for your project.
While installing laminate floor boards on a new construction is easy and straightforward due to the fact that you will have pre-planned the design, specifications and installation, installing laminate floor panels for a renovation or remodelling project is a bit challenging. You will need to inspect the existing room and decide if the existing floor needs to be removed, repaired, altered or left intact in its existing condition. Whatever you choose to do depends on the condition of the floor, its type, your budget, design preferences and existing installations (built-in cupboards, floor heating, ducts and drains etc.) affecting your floor. The existing environment should dictate the solution as well as the best method of handling the job. Check the following:
Level and Even Surface
Existing floors in new and middle aged buildings are flat, level and even to a high level of precision, but as the building ages floors in established buildings may bend, buckle, crack, slope, gap, misalign and wear out due to use, deterioration, damage, ground settlement, expansion and corrosion. Concrete floors in particular exhibit surface waviness over time. Therefore do not assume that every floor is perfectly level. The surface may be uneven, even if it’s a slight change in gradient or elevation. In some cases, the unevenness is clearly visible without needing to measure the levels. There are a many ways to measure the evenness of a floor. You can use a laser level to cast a beam on one side of the wall, then take vertical measurements from the floor to the beam using a spirit level ruler at appropriate intervals between the laser beam ends. The Dipstick Floor Profiler is another instrument that can be used to measure floor flatness and levels. The hand-held dipstick floor profiler is moved and handled like a walking cane. Measurements are automatically taken as you walk across the floor. Another method that you may be familiar with is the traditional 10-foot straight edge method. This simple method involves laying a straightedge on the floor and measuring the maximum depth between the two ends. The distance between the two ends is taken as the unit of measurement expressed as the vertical depth per 1 or 2 metre intervals.
Manufacturers of plank flooring prescribe flatness tolerances for floors on which laminate flooring is to be installed:
Flatness tolerances for floating panel floors: 2mm per 1 metre interval or 3mm per 2 metre interval.
Flatness tolerances for planks (tongue and groove) fixed to the subfloor with glue or nails: 3mm per 1 metre interval or 4mm per 2 metre interval.
How To Fix an Uneven Floor:
To level a concrete floor, you first need to clean the surface. Sweep the floor to remove all loose particles and scrub off all dirt, stains, glue and sticky residues. When the surface is dry, apply a floor primer and leave to dry for a few hours. Prepare and pour some self-levelling compound on the surface. The viscous self-levelling compound will spread over the floor, filling in depressions and low-lying areas. The levelling compound will set after some time, creating a smooth level surface that you can lay your laminate floor panels on.
Levelling a wooden plank floor is a whole different issue altogether. A wood-framed house resting on a timber joist subfloor is usually prone to damage by wind forces, moisture and movement caused by ground settlement. Weakening of joints as well as the longitudinal strength of the joists (sagging) will take place. Floor planks will slant or gap. Plywood sheeting as well as tongue-and-groove panels will bulge due to shrinkage and expansion of wood when it absorbs and loses moisture. The result is an uneven floor.
To fix an uneven wooden floor, you have to determine whether it’s a structural or non-structural problem. Structural members are load bearing and non-structural elements are non-load bearing often functioning as floor cover or cladding. Timber floor joists are structural members. When they are sagging, sloping, twisted, decayed or cracked, you can fix them by attaching a new parallel joist next to them, doubling the thickness of the member. To get the joists to the same level with the adjacent floor or reference point, make sure that the top face of the new joists is level with the reference point.
When the joists are straight but sloping or slanted, find out if you can unbolt the joists and re-align them horizontally. If the joists can’t be moved or shifted, leave them as they are. Take a carpenter’s plane to plane the top part of the joist that is projecting above the reference line, then attach a sister joist next to it.
Fixing a bulging, sagging or damaged plywood floor cover is easy. You only need to replace the plywood with a new board.
Once the floor joists have been levelled and aligned properly with respect to the reference point, you can install the floor panels.
Remove or Repair Existing Floor Cover
The existing floor finish or cover may be in good or bad condition. If a large portion of the floor cover is worn out and damaged, you will need to remove it. Floors with unsuitable substrates such as carpets or padding will also need to be removed before installing laminate flooring. If a small portion of the floor is worn out, the most cost effective option will be to repair the part that is worn out, rather than taking out the whole cover.
Protection Against Moisture Damage
A suitable moisture barrier or damp-proof membrane must be laid over a concrete subfloor, stoneware and earthenware surface covering such as ceramic, porcelain, terrazzo tiles etc. The DPM sheets made of 0.2mm thick polyethylene or other material should overlap by 150 to 300mm and have upturned edges around the floor perimeter. The joints and laps should be tightly sealed with double-sided sealant tape.
Subfloor Moisture Content Management
Natural wood including engineered wood-based laminates will expand and contract as their moisture content (MC) changes due to fluctuations in ambient relative humidity (RH). The amount of water vapour in the air (humidity) can be expressed as absolute humidity (grams of water vapour per cubic metre of air) or as a percentage of the maximum water vapour that air can hold at a given temperature (relative humidity). The maximum amount of water vapour that air can hold at a given temperature is called the saturation point. When air is saturated, the RH is 100%.
Relative humidity is dependent on the ambient temperature and air pressure. According to gas laws, the temperature of a gas is directly proportional to its molecular kinetic energy, volume and pressure.
As the temperature rises, the volume of air increases (i.e. the gas expands with molecules vibrating vigorously and moving further apart). As a result, the air becomes less dense or less saturated with water, leading to a decrease in RH. The opposite happens when temperature drops, leading to an increase in RH. It is important to note that when we talk about humidity, we are talking about the density of moist air or concentration of gaseous water in the air. The density of moist air varies with the amount of water vapour in the air and changes in temperature.
Wood and wood-based products are hygroscopic materials which absorb or adsorb moisture from the environment. The moisture content of wood is dependent on the ambient RH and temperature. When the relative humidity is high (low temperature environment), wood absorbs or adsorbs moisture from its surroundings. Absorption is whereby liquids or gases penetrate the material increasing its volume. Adsorption is whereby liquids and gases are attracted to the surface of a material, forming a thin film or layer on the surface. Mist on windows or dew on green leaves in the early morning are examples of adsorption.
When the relative humidity is low (high temperature environment), wood dries up, releasing moisture into the air, a process called desorption. Wood will keep absorbing and desorbing moisture until its moisture content reaches a state of equilibrium with the environmental relative humidity. This is called the Equilibrium Moisture Content (EMC).
In an environment with unstable and fluctuating relative humidity/temperature, the moisture content of wood will keep changing making it difficult to reach or maintain a stable state of equilibrium. In such conditions, the wood will keep expanding and contracting as it absorbs and loses moisture. The problem with this repetitive volume change (swelling and drying) is that it can cause the wood to buckle, cup, warp or gap. Boards may delaminate, split, crack or check.
To prevent the repetitive expansion and contraction of wood or wood-based laminates, you must make sure that the environment in which the floor boards are installed has a stable climate (i.e. stable RH and temperature).
As you can see, before you install laminate flooring or any kind of wood plank flooring, you must take measurements to determine the ambient relative humidity and temperature on the installation site, as well as the moisture content (MC) of the subfloor. Your subfloor may be timber or concrete. On a timber joist subfloor, multiple moisture test measurements should be taken at different points across the site. The readings should have a minimum and maximum deviation of 2 to 3% between them. Significant deviations and fluctuations between readings indicate excessive moisture in the area which may be troublesome for installation of floor boards. In this case, a remedial solution to decrease the moisture content of timber as well as the humidity in the area is required. A ventilation system (fan and air extractor) can be installed to prevent moisture levels from exceeding the ideal maximum MC of timber subfloor (12%), as well as the RH which is dependent on the local climate and manufacturer’s specification.
A thermo-hygrometer is used to take measurements of the ambient relative humidity and temperature. A wood moisture meter is used to measure the moisture content of wood or wood flooring. There are two types of moisture meters, the pin and pinless meter which work on different principles of physics.
If you have a concrete subfloor, you will need a concrete moisture meter to assess the moisture content in the slab. There are multi-function moisture meters which can measure moisture content in different types of materials such as concrete and wood. As in a timber subfloor, you have to ensure that moisture levels don’t exceed the ideal maximum MC of a concrete screed floor (2%), as well as the RH (<60%).
The purpose of taking moisture content/relative humidity measurements is to determine the stability or instability of the climate in which the floor boards are going to be installed. Measurements should be taken before, during and after the installation of the floor boards. In a new construction, you must not start taking MC/RH measurements until the building is at an advanced stage i.e. until the roof, ceiling, windows, doors and internal wall finishes (plaster and painting) are done. A complete or near-complete building is protected against weather elements, which gives a true picture of the actual environment in which floor planks will be installed and housed. Take MC/RH readings on the subfloor on a daily basis for at least 5 days and keep a record. Analyze the readings and note any fluctuations between the days as well as any fluctuations between different parts of the subfloor. If the variances between moisture readings are very wide, you have an unstable climate. Investigate the cause and install a home climate control system to stabilize the climate. An indoor climate control system might be an HVAC system that includes a humidifier and dehumidifier.
Preparing the Wood/Laminate Floor Panels for Installation: Acclimatization
At this point, you should have a record of the MC/RH levels in your installation site or subfloor obtained from previous measurements. These are the relative humidity of the air on the site, as well as the moisture content of the subfloor. Your next step is taking the wood/laminate floor panels and storing them on the installation site to allow them to acclimatize to the relative humidity in the room. Let’s say the RH is 40% at 80 degrees Fahrenheit (26.7 degrees Celsius), it is possible to work out the moisture content at which the wood is at equilibrium with the ambient relative humidity. This is the EMC value (7.6%) obtained from EMC charts for a specific climatic region. Thus, if the MC of wood at time of delivery was 9%, it should be left on the installation site for at least 3 days to acclimatize to the local relative humidity, until its MC drops to the equilibrium moisture content (7.6%). The opposite is true for a lower MC at delivery. If the wood’s moisture content at time of delivery was 5%, it should be left to acclimatize to the local RH until its MC rises to the EMC (7.6%).
Another way to find out if the MC of wood has reached equilibrium with the ambient RH is to take moisture content readings over successive days (e.g. 5 days). When the moisture content meter starts showing the same readings over successive days, it means the EMC has been reached.
How long does it take for wood or wood flooring to acclimatize to the environment? Most wood laminate floor manufacturers recommend an acclimatization period of no less than 48 hours. However, some recommend acclimatizing your floor panels for 14 to 24 days depending on the MC/RH conditions in your environment. Obviously, a new construction or extensive renovation will need a longer acclimatization period than an established house which only needs a floor renovation. In a new construction, the contractor must wait for the concrete, screeds, plaster and painting to dry, and it takes months for concrete to lose retained moisture although it will harden quickly within 24 to 48 hours and gain maximum strength after 28 days. Newly poured concrete will increase moisture levels on the site which are quite different from post-installation conditions, so it is a good idea to take MC readings after 28 days if you want to be as close as possible to the post-installation climate.
If you are going to use an indoor climate control system to maintain MC/RH levels in your building, it must be turned on 3 to 10 days before the acclimatization begins.
How To Install Laminate Flooring on Prepared Surface
Now that you have prepared your subfloor and acclimatized your floor panels, it’s time install the laminate flooring.
- Open your cartons and inspect the floor boards. Check for any manufacturing defects, blemishes, stains, broken, cracked, chipped, dented, worn out and faded parts. Make sure that no damage was done to the floor boards during transportation, delivery and storage because this is not usually covered under the warranty. Only panels in good shape, appearance and quality should be used for flooring.
- Read the installation manual provided by the manufacturer. Although most of the steps and procedures in preparing and installing laminate flooring are universal, each manufacturer may have slightly different/unique specifications and conditions of installation for their product. As an example, floor panels come in different locking systems such as tongue and groove, angle snap (snap-together) or click-lock.
- Find the best layout for your laminate floor planks. The recommended layout is installing the planks so that their longitudinal side is parallel with the sun’s rays from the main source, or longest side of the room. In rooms with scant or no sunlight or where the room is narrow or small, lay the planks lengthwise to give an illusion of roomy space.
- Roll out underlayment over the subfloor, with its longitudinal side parallel to the direction described in No.3. Basically, the longitudinal sides of the underlayment and planks should be laid in the same direction. Joints should overlap by 150mm minimum to 300mm maximum, including upturned edges around the floor perimeter cut to a suitable height. All joints and edges must be tightly sealed with sealant tape.
If you are doing a renovation, remove existing baseboards (skirting) as well as dividing strips (door thresholds) before laying the underlayment. Since the laminate flooring planks will make the floor a little bit higher, you will need to undercut the door at the bottom to make way for swing opening.
5. Start laying the laminate planks in the direction/layout mentioned in No.3. Laminate flooring planks are available in 6 to 12mm thickness. The thicker the plank, the more durable and hard it is, and the higher its AC grading (Abrasion Class or Coefficient). Hardness ratings range from AC1 to AC5, a higher grade means the flooring can support heavier loads and is more resistant to wear. For home indoor flooring (single family), you will probably need the AC1 or AC2 grade for low-traffic floors.
Laminate flooring planks are 12 to 30cm wide, and 120 to 204cm long.
Thickness: 6 to 12mm
Width: 120 to 300mm
Length: 1200 to 2040mm
Mixed-width laminate panels: Also known as random width or multi-width flooring, this is whereby planks of varying sizes rather than uniform size are used on the floor.
The common practice is to start laying the planks from the corner on the left side of the room moving towards the right. If you are installing tongue and groove panels (angle-snap or click-lock), the edges with tongues must face the wall all around the perimeter of the floor (floor/wall intersection).
Place the first panel on the corner of the room and align it in the right direction. Insert some wedge spacers between the panel faces and the wall. When installing wooden floating floors, you must allow for expansion gaps where the floor meets the walls or any structural feature such as columns and stairs. Wedge spacers are temporarily inserted to allow for expansion gaps. They will be removed after the floor installation is complete. An expansion gap of 8 to 12mm is required around the floor between the face of planks and the wall. It can be as small as 6.35mm depending on the specifications. You can make your own flooring wedge spacers by cutting strips of wood or planks to a suitable size. However, if you want to save your labour or if you need highly precise wedge spacers, it is best to buy commercial flooring spacers like the patented plastic TFloor spacers on Amazon or HomeDepot. A 48-pack is roughly $10.
After putting the first panel, take the second panel and insert its tongue into the groove of the first panel at an acute angle of about 30 degrees, then lower, push forward and press the panel down to lock in place. Do this for subsequent panels until you reach the end of the row. If a full plank can’t fit in the space at the end of the row, you should cut it to size to fit the space taking into account the expansion gap as well. To measure the length that needs to be cut, take a full plank and place it on top of the plank at the end of the row. Push the top plank longitudinally to the end until it touches wall (wedge spacer to be precise). Take a pencil and mark on the top plank the point at which the bottom plank ends. Mark both sides of the plank. This is the point at which the top plank must be cut. Using a high precision electric saw cutter (circular saw), cut the plank along the line joining the two marks. Fit the cut-plank in the end space, and use the remainder to start the second row.
Length of End and Starting Pieces in a Row:
The cut-piece and remainder used in the end and starting space of the row respectively should be no less than 300mm or 400mm in length.
You can work out the end-pieces by measuring the internal length of the room, and dividing the length by the length of the plank:
Length of room – 6500mm
Plank length – 1200
Number of planks – (6500/1200) = 5.4166 No.
Therefore, 5 full planks are required.
End-piece – (0.4166 x 1200) = 499.92mm, rounded off to 500mm.
One end-piece 500mm long is required for the first row.
Width of Planks on Both Sides of the Room:
The width of end-row planks on both sides of the room (the first and last row) should be at least 50mm to 90mm excluding the tongue.
You can work out the end-row space by measuring the cross-sectional internal length of the room, and dividing the length by the width of the plank. This will give you the number of rows required as well as the fractional units (end-space). An example is shown below:
Internal cross-sectional length of room – 4000mm
Plank width – 150mm
Number of rows – (4000/150) = 26.667 No.
Therefore, 26 rows 150mm wide are required.
1 row of width – (0.667×150)=100.05mm is required, rounded off to 100mm.
What if the width of end-row space is less than the minimum? In this case, you should subtract the minimum from the first-row plank to ensure the last-row plank is wider than the minimum. Alternatively, the end-row space can be added to the width of a full plank, and then divided by two to ensure that both ends have evenly sized planks.
You don’t necessarily need to subtract the minimum from the first-row plank. As you lay the boards and approach the last row, it’s obviously clear if the last-row space is less than or greater than the minimum. In order to fit a full-width plank in the last-row space, start by measuring. Take a full-width plank and place it on top of the plank in the last row, aligning it lengthwise. Push the top plank against the wall, then mark a line on the bottom plank where it meets the edge of the top plank. The longitudinal line mark is where the bottom plank should be cut to free up space and accommodate a full-width plank in the end-space.
Trim the Upturned Edges of Underlayment
Once the last row has been laid and the floor installation is complete, trim the upturned edges of underlayment protruding against the wall, using a razor knife or underlay/vinyl line trimmer. The upturned edges must be trimmed to the top surface of the floor panels.
Floor Panel Layout Pattern
The boards should be laid in a staggered pattern also known as the stretcher bond. The minimum distance between the staggered joints of panels in successive rows should be 200 to 400mm depending on the length of the board. As a rule, the minimum distance between staggered joints in successive rows should be one-third the length of the board.
Cover Perimeter with Skirting, Baseboard or Moulding
An expansion gap of 6.35 to 12mm is allowed for around the floor perimeter in contact with the walls, as well as around kitchen and bedroom floor cupboards. This expansion gap must be covered for aesthetic purposes with quarter round skirting or moulding. It’s a good idea to match your skirting with the floor finish. Wood and PVC skirting is suitable for laminate floors. The baseboard can be fixed to the floor/wall junction using glue, nails or screws. It must be fixed to the wall and not the subfloor or floor panels. When nailing the baseboard to the junction, use an air gun, pin nailer or the traditional hammer and nail.
If you are installing laminate flooring on existing floors, you may choose to leave the existing baseboard in place, but you must install quarter-round moulding fixed to the baseboard to cover the expansion gaps.
Bathrooms and other Wet Areas: Expansion gaps around the floor, bathtubs and shower bases must be caulked i.e. filled with 100% silicone sealant to make them watertight. Fill the joints to the brim and scrape off excess caulk with a strip. The joints can be covered with quarter-round moulding if they are straight (not curved or circular).
Normal / Dry Areas: Floor perimeter expansion gaps in normal dry areas such as the bedroom or living room are usually left void to allow room for expansion, but they can also be filled with a flexible and highly compressible material such as PE foam backer rod. The polyethylene backer rod is made in the form of a flexible rope which can be laid in the expansion gap, and then sealed with 100% silicone caulk. The gap is then covered with quarter-round moulding.
Before you install the baseboards, you have to remove the wedge spacers around the perimeter of the floor.
Gaps on Mitred Ends, Corners and Under Door Jambs:
Gaps between mitred ends and corners on baseboard mouldings and under door jambs must be filled with 100% silicon caulk to achieve a continuous profile with the finishes.
A transition profile is also known as a dividing strip, transition strip or floor divider strip. The line where two floors meet at different heights or where different floor finishes meet is covered with a transition profile. Transition strips installed on entrances or doorways are known as threshold bars or strips. They are usually made of aluminium or synthetic plastic (e.g.PVC), but also available in the form of rubber, wood, stainless steel, brass and other alloys.
There are two types of transition profiles, a transition strip for floor surfaces which are at the same level, and the other for floor surfaces which are at different heights. A T-molding transition strip is installed between floor surfaces at the same level, and a Reducer transition strip is installed between floors of different heights to form a slope or ramp.
Floor divider strips can be installed with or without base metal tracks (channels) depending on their design specifications. In a new construction, you will start by installing metal tracks on the subfloor before installing laminate flooring. If no metal tracks are needed, then you should measure and mark a line on the subfloor where the Reducer strip or T-mold transition strip is to be installed. The line mark serves as a boundary on which installation of laminate flooring should end.
Metal tracks for transition strips are fixed on the subfloor using screws, nails or heavy-duty construction glue such as Gorilla Glue or Liquid Nails. When installing transition strips, the minimum expansion space (6.35 or 8mm) must be maintained between the flooring and the vertical part of Reducer or T-moulding. Depending on their design, both Reducer and T-mold transitions can be fixed on base metal tracks by simply snapping them in place. However, trackless transitions (especially those made of wood or PVC) are fixed directly on the subfloor using heavy-duty construction glue. When gluing the transitions to the subfloor, make sure that the glue does not spread, clog or fill the expansion space.
Transition mouldings (as well as baseboard skirting) should not be fixed, screwed, nailed or glued to the laminate flooring as this defeats the purpose of floating floors.
Where there is underfloor heating installed, transition strips should be glued to the subfloor rather than nailed or screwed.