What Type of Underlay Is Best for Artificial Grass?

While you won’t notice it once your turf has been laid, installing the correct underlay is vitally important and may even be a legal requirement. So what kind do you need to use?

In most cases, a foam shock pad is the best underlay for artificial grass when it’s being installed on soil. For artificial grass that is going to be laid on decking, balconies, or rooftops, a foam pad underlay is essential. Foam pads provide a safe, comfortable, and level surface with excellent drainage.

This article will show you:

  • The benefits of using foam shock pad underlay
  • When installing foam pads is a legal requirement
  • Why weed membranes are a good addition

Foam Shock Pad Underlay

For some uses and areas, a foam shock underlay may be a legal necessity. For example, if you are installing a sports field or play area, you will find that your local safety inspector will want to see if there is adequate padding.

An underlay is a vital drainage material if you live in a region with heavy rainfall or if you plan to hose your grass every time your pet urinates. The foam also helps with the feeling of the turf, the appearance, and how it reacts to your feet. Benefits include:


The soft appearance of artificial turf can mislead children and adults into thinking that it is enough to cushion a fall. But without an underlay, a person or pet can suffer severe injury from falling on a solid material, such as concrete, beneath your artificial turf.

There are also legal ramifications for not following Head Impact Criteria (HIC). Not installing an underlay when the intention is to use the area for a school or a playground can lead to rejections of permits or large fines.

HIC inspectors will visit a finished artificial grass pitch after installation. It is standard practice for the HIC to assess the impact absorption of a headfirst fall to see if the shock pad is absorbent enough. The rules are even more stringent if swings or play equipment, which can increase the fall height, are present.


Fake turf is a thin mat with artificial blades of grass woven onto it. The thickness makes it easier to install and glue down, but this thin mat offers little in the way of separation from the hard ground it sits on.

Even if you are not using the turf for sports, the lack of an underlay is going to be noticeable underfoot. A foam mat will make the turf feel more luxurious and natural.

Kids and pets will prefer the feel and be more encouraged to play outside. And parents can rest easy with the knowledge that their artificial grass is safe for their children to play on.

Simple Transformation

Concrete outdoor spaces such as balconies and terraces are easier to convert to safe green grass if you use an underlay. The foam will give you more grip and help prevent you from slipping if the artificial grass gets wet.

Foam mats are quick to install, and you have the possibility of rolling up the grass in the winter and just using the mat.

Levels Surfaces

Artificial grass is a fantastic way to hide old and broken concrete slabs and sunken soil. With a foam mat, the dips and bumps will be less noticeable than if you try to lay your artificial turf straight over these imperfections.

The same applies to installing fake turf over decking, where the ridges between each deck board will become more visible over time. The sun and constant bombardment by rain and foot traffic will develop these dips and may even cause taring.

A thin 8mm Soft Turf Pro shock pad will even out these lines, lessen the strain on the grass weave, and prevent uneven discoloration.


Professional fitting of artificial grass over soil or paving slabs involves digging up the surface. And after removing a top layer, a sub-base needs to be added back in for drainage and to prevent weed growth.

Foam matting does both leveling and weed prevention in one product. A mat underlay also seals the surface in a way that still allows water to drain away quickly without the need to install extra drainage.

The mat also speeds up the installation process of artificial grass. Glue applies directly to the foam, so it takes the brunt of the contact abrasion from foot traffic. The grass can then be laid on top of fitted foam without the need for a layer of glue to attach the two.

And since you do not need to remove a layer of soil or concrete, you save on the cost of not needing to rent a skip for the day to dispose of it all.


Leveling out and preparing the groundwork with gravel involves hours and days of manual labor. Removing rubble and soil with a wheelbarrow takes a long time and an extreme amount of effort.

And if you have an extensive garden with big distances to transport gravel from where you unloaded it, you are going to feel the strain even before you get to leveling. Foam mats are lightweight and easy to carry, making positioning, leveling, and securing easy and quick.

Underlay with Drainage

Foam pads do more than just improve the appearance and safety of your turf: they also level the ground. An underlay is a vital stage of getting the base ready for water runoff. The underlay prevents stagnant water build-up beneath your artificial turf, which would cause it to develop mold.

These foam shock pads are useful on soil but vital on concrete balconies, terraces, or over decking. If a foam underlay is used in conjunction with drainage mesh, you will find that you get excellent water runoff, even during severe storms.

Rooftop terraces are notorious for leaking through to lower apartments. These leaks are often due to trapped puddles building up over the waterproofing. An underlay helps protect the water sealants on the terrace and prevents the kind of blockage that prevents water from draining away.

An underlay also helps pet owners to keep their artificial turf sanitary. A mesh and polyethylene foam underlay are a huge help when you want to hose down your fake lawn with cleaning products and water.

And pets will find dry turf with a drainage mesh more comfortable to play on or take a nap on when the sun comes out.

Weed Membrane

Even chemicals struggle to kill off dormant vegetation, and it still means going around trying to manually pull weeds and their roots up. Weed membranes are inexpensive and far cheaper than constant applications of herbicides.

Being a non-woven fabric, the gaps are too small for shoots to make their way up through the membrane to your turf. The membrane also absorbs light, taking away the most important source of fuel for weeds.

Joshua Milton

I want to share everything I know about home improvement in order to help you. Whether you're a home enthusiast or an industry professional, I have the information that you need.

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