Screeding. The secret to a perfect laminate floor.

The sub-floor has to be absolutely flat - 90% of your worries will then be over. Don’t scrimp on the screeding; this is the whole secret to a long lasting trouble free floor. Screeding is a touchy subject but forms part of the job. It costs money to screed. Any laminate floor relies on a flat surface to operate and survive on. Only then then has it a chance to fulfill its guarantee. Levelness of the floor must be down to 2mm. Don’t be foxed by ceramic or marble floors – they are not laid flat. The laminate floor needs a very flat floor to be able to fulfill its 30 year guarantee. A laminate floor is not meant to go up and down. The 2mm foam underlay only takes up a minute amount of unevenness. Any mechanical stress weakens the joints and this affects the guarantee. The Guarantee is on the product only and not the fitting or workmanship. Creaking and squeaking sounds need movement to make the sound. No moving up or down, no squeaking or creaking. Fitting laminate flooring over slate floors is not a good idea. The screeding and plastic trap the rising moisture in the slate and it swells, pushing the floor up. Laminate floors cannot be fitted over old style parquet flooring. The moisture is trapped in the old parquet and it swells, pushing the laminate up. Hollows and dips in the sub-floor can’t be filled with double layers of foam, newspapers, cardboard, magazines etc. This is a short cut to screeding to cut down on costs. The laminates will fail and you lose the guarantee. Remember if the floor is stressed and flexes as a result of the bad sub-floor and then the joints fail, it wasn’t the joints failing, it was the bad preparation that caused the joints to fail and hence the guarantee won’t cover that situation.

The laminate floor is not there to cover the imperfections of the sub-floor/concrete. It is the opposite. The laminate planks rely on the sub-floor/concrete to support them. That’s the way it’s manufactured and set up.

How do you see if a floor needs to be screeded?

Only with a straight edge. It can’t be judged with the eye, especially if the floor is still carpeted. Only once the carpeting or previous covering has been removed, will you be able to see whether the floor needs to be screeded. Do this with a 2 meter straight edge. The tolerance is 2mm over 1 meter. Hollows and peaks are not good news. Peaks need to be chiseled away.

Moisture barrier.

Plastic sheeting / membrane must always be used, even with rubberlay. 200 micron is ideal and the thickness of the foam should be 2mm only.

Once the floor has been leveled to manufacturer’s specifications a moisture barrier has to be laid. A moisture barrier, traditionally plastic sheeting, has to be fitted with all laminate floors - including when fitting over ceramic, marble floors etc. Not all plastics are the same. Thin plastic eventually allows moisture to come through. That’s why a specific thickness is specified by the manufacturer. Prior to laying the plastic or combilay, the floor has to be SWEPT ABSOLUTELY clean. Any small pieces of grit, chips of concrete, will cut through the plastic and allow moisture through to the laminate (believe it, it has happened). The small rock or chip of concrete will also push through the laminate and cause the top of the laminate to “crack up”. Allow the plastic to run up the wall for about 5cms. Trim once the floor has been finished. If for some reason water does come in from the walls, it acts as a barrier to the wood.

Laminate floors can’t be glued to a sub-floor. The moisture in the sub-floor will infiltrate the laminate and make the edges curl up.

Water and moisture.

Like any wood product, laminates don’t like water. It’s wood. Wood absorbs water. A shower cubicle opening out direct into a bedroom will have the opposite effect on the laminate floor in another room without a shower attached.

Humidity.

Humidity definitely plays an important part in the life of a laminate wood floor. Wood absorbs moisture in heavy wet conditions and in dry conditions releases the moisture and dries out. . Gaps can appear in the laminate floor if the atmosphere is very dry. Expect gaps to appear if a steady humidity level is not maintained. Humidifiers are recommended where there are extremes of weather. Different rooms have different atmospheres. Air-conditioning in one room and not in another, has a different effect on the floors. If there is no joining profile at the door way, the wood in the two rooms is now pushing against itself. In one room it’s hot and in the other it’s cold. Each floor is going to react differently and “fight” against itself. Flower beds right up against a wall, cause dampness in the room (the walls get wet when the sprinklers are on). Customers must keep their outside doors closed when the sprinklers are on. It sprays right onto the laminate floors. A crack in the concrete sub-floor will allow more moisture in than normal. Ice makers on the outside of fridge doors drip water onto laminate floors. Dish washers splash water onto laminate floors when opened. Dripping hose joints on dish washers and washing machines drip water onto laminate floors.

Flood damage.

When a laminate floor is flooded, it is recognizable as a characteristic raising of the surface layer and under layer, flowing towards the centre of the plank away from the edges. Depending on the amount of water, the swelling can occur through to the middle of the floor. Beware of water sliding down outside sliding doors. The water accumulates in the “U” shaped channel and seeps into the house.

Cleaning.

Cleaning is included here because water is needed to clean a floor. But you can’t mop a laminate floor. All you need is a slightly damp cloth. Wet a cloth and wring it out as much as possible. That’s all you need. The result of mopping a laminate floor or letting spilt liquids lie on the floor too long, is the curling of the edges of the planks. Very noticeable.

Laminate Flooring is a free floating floor. It needs to expand sideways and length ways, but not move up and down.

Follow the manufacturer’s fitting instructions. Different manufacturers have different specifications. Don’t fit the laminate flooring with obvious defects.

Have a brush handy to brush the joints on each of the planks – it brushes away any small pieces of laminate or dust left behind from the manufacturing process. Small pieces of wood or dust can cause an open joint at the time of fitting. Different manufacturers have different gap requirements for around the walls and fixtures. Kaindl is 10-12mm.

Laminate joints can be felt. There is a certain tolerance that is allowable in the specifications and guarantee. Do not fill the gaps against the wall with silicone. The gap is there for a purpose to take up the expansion in the floor. Silicone does not compress to the amount required by the moving floor. Do not glue the floor to the skirting. The floor must be able to slide under the skirting. A grand piano or heavy bookcase in the room, anchors the laminate to the sub-floor. The floor is then no-longer free floating and starts to tear itself to pieces. A pool table will also anchor the floor to the sub-floor. Cut holes in the laminates and let the pool table sit directly on the plastic. There is now a gap between the laminate and the feet of the pool table. Get a carpenter to turn a ring with an inside diameter equal to the outside diameter of the foot. Cut the ring in half and glue it round the foot. It covers the gap and lets the laminate still move Rugs Don’t put rugs on laminates with under-floor heating. The rug traps the heat in that particular area and causes excessive heat buildup and extra tension in that part of the floor. Under-floor heating has to cover 95% of the laminate flooring. The entire laminate floor must heat up equally.

Office chairs with wheels Yes, but with soft rubber wheels. Not those hard polypropylene wheels. If you use the hard plastic wheels, it wears the edges of the planks away. Very clear to see. Also tends to wear away the floor under the two front wheels, where most of the weight is.

Scratch proof?

No. Laminates are scratch resistant not scratch proof. (See guarantee and fitting instructions). Treat all laminate floors like you would any other prepared surface. Would you cut a roast on the kitchen counter top? Is the cutting board all cut? Does a proper wooden floor that has been sealed, get scratched? Can a wooden sideboard get scratched? Do stainless steel pots and pans get scratched? They all do. An entrance/walk off mat must be installed at all external entrances, to wipe the grit off the soles of shoes. Grit on the soles of shoes is like walking with sandpaper glued to the shoe. It’ll wear away the protective layer.

Laminates can’t be sanded.

Laminates can’t be manually polished and can’t be polished with a polishing machine. Laminates can’t be sealed with a sealant. They can’t be varnished.

Consumer errors.

Under floor heating in conjunction with rugs. Not allowed. The rugs trap the heat at those points and distort the floor. Only that part of the floor heats up and expands. The floor then distorts and pulls itself apart. Consumers must be made aware of this. Excessive water being used for cleaning, immediately recognizable from the floor peaking. Heavy objects on the floor i.e. pianos, very heavy tables etc., these anchor the floor to those particular spots. The rest of the floor expands and contracts around those objects and pulls itself to pieces. The floor as a whole should be free to move as one. Floors scratching - not enough cleaning or too much dirt being tramped into the house. Floors are scratch RESISTANT, not scratch PROOF. All wood scratches. Tiles scratch. Use correct entrance mats.

BUT, LAMINATE FLOORS DECENTLY INSTALLED, REALLY DO LOOK GOOD!!