Why lay the film under the laminate

Why lay the film under the laminate Why put the film under the laminate - which varieties to choose

Prior to the installation of a floating floor, customers who are competent in the renovation industry ask from time to time why lay the film under the laminate. Here you can write about the clarification that the film is placed under the substrate.

In the technical documentation and instructions, which is in the package with laminated parquet, it is written: "In order to provide warranty service, it is required to install steam insulation with a thickness of 0.02 cm or 200 microns."

We suggest you figure out what polyethylene is required for to protect against moisture and how well it works.

General information

It should be noted that in the last year, according to observations, the vapor barrier PVC film under the laminate has a strong unpleasant odor, and this completely negates the idea of ​​using materials such as cork or parquet board. The second point, which was not previously mentioned, is that the spread of the film creates air pockets due to the folds. And when laying further on top of the film, the lining does not fully adhere to the floor. After the laminate installation process, different sounds can be detected. Naturally, the air will escape in the future, and the material itself will settle.

Please note that most types of laminate are specially protected from the bottom against water ingress. It will be contained in the bottom layer, which consists of melamine resin or craft paper, which does not allow moisture to pass through, and also covers more than 99% of the plank surface. The chance of panel joints hitting the substrate seam begins to tend to zero, and the probable area of ​​contact of the unprotected areas will be equal to 0.000….


Vapor barrier film for laminate

Why lay the film under the laminate The inserts, which are in the package with the material, inform about the provision of a warranty period for 10 to 25 years.

If you take a little time and find the manufacturer's website on the Web, then you can find conditions that will necessarily apply exclusively to panel wear damage.

In this case, the warranty service does not lend itself to a coating with various abrasions along the board edges, from where, in general, material damage begins. It turns out that the obligations from the Classen factory under the guarantee, for example, extend only to the surface of the laminated floor, and even then, not all.

Not a word is said about the film for vapor insulation, it is only said that when installing the laminate, it is necessary to comply with all the conditions that are described in the instructions. And the manual states that a 200 micron thick waterproofing film is required.

It is interesting that the use of film under the laminate in order to keep the manufacturer's warranty is a complete fiction and is only one of the additional required conditions. It makes no sense to use steam insulation just for this.

There are no world-known warranty replacements for a laminate from the manufacturer. For many years, there was no laid-on film where the old floor covering was dismantled, including in new buildings.

Film for a laminate on a concrete base

All multi-storey houses are built of reinforced concrete.

For this reason, otherwise, the flooring of the flooring type in cities is produced precisely on concrete or on top of the old type of parquet, which is laid on the interfloor ceiling. We, specifically for covering the film under the laminate, will be interested in the first described case. Omitting the warranty period, which cannot be called anything else but a "phony letter", we will determine in which cases a film for insulation from moisture will be needed.

Laying the film on a concrete base in a house above the 1st floor

Craftsmen have to regularly deal with laying laminate on a concrete base in old and new houses. Basically, there is no need to lay moisture-proof polyethylene.

If the house will stand all season and is equipped with centralized heating, then film flooring under the substrate does not make much sense.

Spread additional protection against moisture in the following two cases:

  • If you have recently filled the floor with self-leveling mortar. The standard drying time before laying the floor covering is 5 to 7 days with the heating on.
  • Leveling the base using a sand-cement mixture on a layer of approximately 5 cm. The full cycle of moisture release is 1 day.

  • You can check the residual moisture level by spreading a newspaper or napkin, covering it with a polyethylene film, and attaching tape around the edges and leaving it overnight. If the paper starts to damp, install the laminated floor in advance.

Now let's consider the features of the flooring for the substrate.

Flooring for coniferous and cork backing

So, you know why you need a film for a laminate. It is required to be slightly stricter when laying additional film for a substrate made of materials of natural origin on a concrete base.

This will mainly concern the surface leveled with a water-based mixture. In multi-storey buildings, it is not required to lay moisture insulation on any wooden surfaces, be it chipboard, plywood or parquet.

When is it necessary to apply the film under the laminate?

There are cases when it is necessary to apply the film under the laminate, and we suggest considering all the options.

  • There are different situations. The story of one specialist: "There was a situation when a foreman went to a country house in winter to measure.

    The built cottage was of a summer type, the base was on screw piles, but the screed was made of cement. And the customer asks - it is required to lay a laminate, and the foreman said that in such conditions it is impossible to lay the floor, since mold quickly begins to spread from below.They replied that after the work of past specialists, the cork substrate under the coating had rotted, covered with fungal colonies.

  • Why lay the film under the laminate It is difficult to say what the customers were guided by when trying to re-lay the floor covering, stepping on the same rake. But the vapor barrier film would then prevent mold from getting on the cork backing.

    But such a situation would have worked like a time bomb. The fact is that the presence of a large amount of moisture under the film and the complete absence of ventilation, in any case, could have contributed to the appearance of the fungus.

  • Example history. Dano is a flooded apartment (completely), because the people in the bathtub had a tap pulled out and an accident happened. The owners of the apartment were not at home, the water leaked into the premises, which were located below the floor.

    The disaster had to be stopped by cutting off the water supply through the common riser. Arriving at the address, it was necessary to dismantle the laminate and coniferous substrate a week after the flood. The lining was rotted and covered with fungal colonies, even the concrete base turned black. I had to dry the concrete screed for about a week before starting to lay the laminate.

Would vapor insulation tape help in this case, and how much? Let's say a black protective film of 0.

02 cm is laid with an overlap on the walls, on top of each other and is well glued with a wide clerical tape, to create a trough shape. Naturally, all the cracks and gaps could not be blocked - they are located near the heating pipes, in doorways, polyethylene can break due to small pebbles. For this reason, we will consider that polyethylene will only delay the ingress of water into the screed for a certain time and further, down to the neighbors.

Naturally, in the short term, for example, if the hose jumped out of the washing machine on time, a film for moisture insulation will help, but no more.

Perforated vapor barrier film for laminate

Sometimes customers ask to lay a vapor barrier film, which has perforation, under the foam backing.

You know, there is a deep meaning in this waterproofing. With good insulation of the first floor of the building and the ingress of residual moisture into the final layer on the subfloor, and this remaining moisture, the vapor insulation can dissipate in a metered manner. Remember that coniferous and cork substrates, tepleks can, by design, cope with a small amount of moisture, dispersing it inside a personal structure. Whether or not to install vapor insulation under the laminate is up to you, and below is a short table of using a protective film.

The need for film for vapor insulation Old concrete base New cement screed Wood base Country house
synthetic backing - - - ?
Natural backing - + - -

( 1 grade, average 1 of 5 )