Best underlay for high traffic?

High (or heavy) traffic is one of the most important aspects to consider when we choose a floor underlay. First we need to know the type of floor we want to support with an underlay. Different floor types have different requirements all of wchich are defined precisely by the organizations dedicated to it. I mean EPLF for laminate flooring and MMFA for multilayer modular flooring.

High floor traffic means we will be walking on the floor all day making different momentary pressures in many different spots. It applies in:

• offices,
• shops,
• but also in the corridors of our appartment or house.

Compressive strength (CS) is a parameter describing the ability of an underlay to support a heavily used floor. This reflects the amount of pressure we need to apply to the floor in order to squeeze down the underlay 0.5 mm underneath it.

Picture: property of Fair Packaging Sp. Z o.o. Sp.j.

According to the EPLF heavily used laminate flooring must be supported by an underlay with a compressive strength of at least 60 kPa.

kPa (kilopascal) is the unit of PRESSURE. The simple definition is: 10 kPa is a pressure applied by a weight of 1 Ton (1 T) to an area of 1 square meter (1 m2).

Picture: property of Fair Packaging Sp. Z o.o. Sp.j.

60 kPa means 6 Tons of weight imposed on one square meter of flooring in order to compress the underlay installed under it by 0.5 mm.

Looks like quite a lot of weight, right?

• For laminate floor: in general to meet this requirement you will need an underlay made of high-density PE foam, e.g. 100 kg / m3 or more. A good example of such underlays are our Max LINE products.

• For multi-layer modular flooring things get a bit more complicated. According to the MMFA recommendations for underlays we first need to determine the type of vinyl floor we will be installing. MMFA divides multi-layer modular floors into 2 groups:

• • category MMFA “Wood” – with HDF core: the recommendations are the same as for laminated floors that are intensively used: a CS value of not less than 60 kPa is sufficient.
• • MMFA categories “Polymer” or “Mixed” – without HDF core: there are completely different requirements for the CS value. It should be not less than 400 kPa! This means 40 tons of weight imposed on one square meter of flooring to compress the pad under it by 0.5 mm. It’s extremely heavy, isn’t it?

I can recommend only a few products wchich will fulfill this requirement. One of them is our Lvt ALU Extreme underlay made of natural rubber and providing a perfect footstep noise cancellation at the same time.

Let’s summarize:

For Group 1 laminate and multi-layer modular floors with an HDF core, an underlay with a compressive strength (CS) of not less than 60 kPa is required.

Picture from the official MMFA materials: 2020 - Compact info sheet: Underlay materials

There is no recommendation for multilayer wood flooring but as a specialist I would choose a natural rubber underlay mainly because of its additional functions beyond its extremely high compressive strength.