October 10, 2024, 10:35 am | Read time: 6 minutes

If you want to lay new flooring and the subfloor is uneven or unstable, decoupling mats can help. These protect the new material from breaking and ensure stability.

What is a decoupling mat?

In the construction industry, craftsmen and building professionals often use decoupling mats, also known as decoupling membranes or decoupling fleeces, to minimize tension between different materials. These mats are often used in tiling work and when laying natural stone. However, they can also be used when laying screed, concrete, and wooden floors to prevent cracks. Thanks to their versatile application, decoupling mats can extend the longevity of floor coverings.

What is a decoupling mat used for?

To compensate for temperature differences

Decoupling mats are used when several materials lie on top of each other and react differently to temperature differences. Some floor coverings, such as wooden floors, either contract or expand in hot or cold conditions. As the material does not lie motionless on the subfloor due to temperature differences but expands, these tensions can be reduced with decoupling mats. As a result, the surface covering is less likely to be damaged or develop cracks.

Settlement on the building

New buildings often move on their foundations over time, which is known as settlement. It usually takes around seven years for new buildings to settle completely. During this process, there are usually no cracks in walls, ceilings, or floors, so this natural settlement process should not be a cause for concern. However, during settlement, decoupling mats can act as a buffer to compensate for these movements and prevent possible damage.

Sound insulation

Decoupling mats minimize noise generated by walking on flooring. These impact sound-absorbing mats absorb vibrations and movements from the subfloor and prevent them from being passed on to the floor covering above. This can be particularly useful for parquet and wooden floors, tiles, and mixed subfloors in order to reduce disturbing noises.

Drainage and moisture protection

Effective moisture protection can be achieved with decoupling mats, especially when renovating an old building and laying tiles on wooden floors. A tiled floor is often not completely watertight, allowing water to seep through joints or tiles onto the wooden floor. This can lead to mold growth and may require the entire floor to be torn out. Decoupling mats not only protect the floor from cracks but also prevent moisture from accumulating underneath the tiles.

What types of decoupling mats are there?

There are different types of decoupling mats, which are usually available in rolls of different lengths. These rolls can be easily cut to size as required. Alternatively, you can also buy individual mats. Rolls are used more frequently because they can be laid over a larger area and can also be cut more flexibly. Individual mats can be used for smaller projects.

There are also mats that are specially designed for tiles and are suitable depending on the intended use. For example, some mats are more suitable for tiles and others for wooden floors or screeds. There are also mats that have been specially developed for sound insulation or moisture protection.

When buying decoupling mats, you should always pay attention to the thickness of the mats, as this can affect the height of the floor covering. If the mats are too thin, the flooring may not be sufficiently decoupled, which will require the use of more adhesive or thin-set mortar to ensure a level surface.

How are decoupling mats made?

The mats are often made of plastic, rubber, foam, or other suitable materials and consist of several layers. The surface of these mats can often have different structures. Dimples, grooves, or honeycombs can improve the stability of the decoupling mats. The underside is usually designed with air channels or air chambers.

How are the mats laid?

The mats can be glued to the subfloor using special adhesives. Thin board mortar is usually used. There are also decoupling mats that can be laid loose. It is best to follow the manufacturer’s instructions when laying. Below, you will find step-by-step instructions:

Step 1: Clean the subfloor

You should clean the subfloor beforehand and remove any dirt, dust, oil, or old adhesive residue. The substrate must also be dry, clean, and even.

Step 2: Check the subfloor

You should make sure that the floor is load-bearing and stable. If necessary, the subfloor can be leveled with a leveling agent.

Step 3: Planning and cutting

First, you should measure the area to determine the required quantity of decoupling mats. Once you have calculated the quantity, you can cut the mats to the right size and shape. This can be done with a cutter knife or sharp scissors.

Step 4: Laying

Now, you can apply a suitable adhesive to the substrate and press the cut mats onto the adhesive. There should be no cavities or air pockets so that the decoupling mat can adhere well. Joints should be well connected; if necessary, the transitions can be sealed with sealing tape.

Step 5: Drying time

The adhesive should be allowed to dry completely before proceeding to the next step. The drying time can vary depending on the adhesive but can often take up to 24 hours.

Step 5: Laying the floor covering

Depending on the floor covering, you can now start laying it. The floor covering can be laid on the decoupling mat. However, you should follow the manufacturer’s instructions.

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What do decoupling mats cost?

Decoupling mats are typically sold in rolls measured by the meter. The price is often based on the number of square meters. However, prices can always vary depending on the material quality, thickness, and manufacturer. Many manufacturers offer guarantees on their products, which in turn can be a good sign of reliability. At DIY stores, prices for decoupling mats start at just a few euros per meter, whereas professional manufacturers may charge upwards of 200 euros per roll.