The Best Artificial Grass Underlay for Concrete

Concrete is one of the trickier surfaces for artificial grass because it is hard, unforgiving and often less free-draining than a prepared soil base. The right underlay can make a grassed patio, balcony, play space or garden path feel softer, safer and more comfortable underfoot while helping the finished surface sit neatly. This guide explains what to look for, when artificial grass padding is worth using, and how to choose the best artificial grass underlay for concrete without overcomplicating the job.

What is the best underlay for artificial grass on concrete?

The best underlay for artificial grass on concrete is usually a purpose-made foam shockpad or artificial turf underlay that is suitable for outdoor use, allows water to move through it, and gives enough cushioning for the way the area will be used. It should sit securely on the concrete, support the grass evenly, and avoid trapping moisture underneath the installation. The right choice depends on whether the space is decorative, family-focused, pet-friendly, used for play, or simply designed to make a hard patio feel more comfortable.

A concrete surface gives you a solid, stable base, which is useful. Unlike soil, it does not usually need extensive excavation or compacted aggregates before grass is laid. The downside is that concrete has no natural softness and can make artificial grass feel thin or harsh, especially if the chosen grass has a shorter pile. That is where a suitable underlay makes a noticeable difference.

Underlay is not always essential, but it is often the detail that turns an acceptable installation into a comfortable one. It can reduce the hard feel of concrete, help disguise minor surface imperfections, and create a more forgiving finish for children, pets and everyday foot traffic. For many domestic spaces, the best artificial grass underlay is the one that balances cushioning, drainage, durability and ease of installation.

Why concrete needs a different approach

Artificial grass laid over soil is normally installed on a shaped, compacted sub-base that allows rainwater to drain away. Concrete behaves differently. It is solid, flat in places, sloped in others, and may already have drainage channels, cracks, dips or old surface coatings that affect how the finished grass performs.

If you lay turf straight onto concrete, the grass can look fine at first. However, it may feel hard underfoot, particularly if the pile is dense but not very deep. Any raised edges, small ridges or uneven patches in the concrete can also become more noticeable once the grass is walked on. Artificial grass padding helps soften that relationship between the grass and the hard base.

The other important issue is water. A concrete patio may appear level, but most outdoor slabs are designed with a slight fall so rainwater runs towards a drain, border or edge. If underlay blocks this movement, water can sit beneath the grass and cause smells, staining, algae or a generally damp feel. That is why ordinary indoor foam, carpet underlay or non-draining materials are poor choices outside.

A purpose-made artificial turf underlay should be selected with the surface in mind. On concrete, it needs to provide comfort without creating a sealed layer. It should also work with the adhesive or fixing method being used, because a soft underlay that shifts around will make the grass feel loose and poorly fitted.

The main types of artificial grass padding

There are several materials people refer to as artificial grass underlay, but they do not all perform in the same way. Understanding the common options helps you avoid using a product that seems convenient but creates problems later.

Foam shockpad underlay

Foam shockpad is one of the most common choices for artificial grass on concrete. It is designed to add cushioning beneath the turf, making the area feel more comfortable to walk, sit or play on. It is particularly useful where children will use the space, where people may walk barefoot, or where the concrete is too harsh to leave directly beneath the grass.

Outdoor shockpad should be water-permeable or shaped in a way that supports drainage. It also needs enough firmness to avoid feeling spongy or unstable. Good artificial grass padding should compress slightly under pressure, then recover its shape rather than flattening quickly.

Foam underlay is often used on patios, roof terraces, balconies, play areas and around garden seating. It can make a big difference when paired with shorter artificial grass because it adds softness that the pile alone may not provide. For deeper, more luxurious grass, it can still improve comfort, although you may not need the thickest option available.

Rubber-based artificial turf underlay

Rubber or rubber-like underlay can provide a firm, resilient layer beneath artificial grass. It may be used where a tougher or more impact-absorbing surface is needed, depending on the product. Some systems are designed for playgrounds or sports-related surfaces, though domestic garden installations usually do not need anything overly technical unless the area has a specific safety requirement.

The key is suitability. Not every rubber mat is right for artificial turf, especially outdoors. Some may hold water, smell in warm weather, mark the concrete, or prevent adhesive from bonding correctly. If rubber-based underlay is being considered, it should be selected as part of a proper artificial grass system rather than improvised from gym flooring or indoor matting.

Drainage mats and void-forming layers

Drainage-focused underlays create a space beneath the artificial grass so water can travel towards an outlet. These are useful where the concrete does not drain as freely as you would like, or where the area is exposed to heavy rain. They can be particularly helpful on balconies, terraces and enclosed courtyards, where water has fewer escape routes.

A drainage mat may not feel as soft as a cushioning shockpad, although some products offer both functions to a degree. The practical question is whether comfort or water movement is the priority. In some installations, a drainage layer beneath a softer artificial turf underlay can be appropriate, but layering materials should be done carefully so the surface remains stable.

Geotextile membranes and weed membranes

Membranes are sometimes confused with underlay, but they serve a different purpose. A weed membrane can help prevent growth from cracks or joints, while a geotextile layer may separate surfaces or reduce rubbing. On solid concrete, weeds are usually less of a concern than they are on soil, but cracks, edges and nearby borders can still allow growth.

A membrane does not provide meaningful cushioning. If you want a softer finish, you need artificial grass padding rather than just a fabric layer. A membrane may still be useful as part of the installation, but it should not be treated as the best underlay for artificial grass on concrete if comfort is the goal.

Materials to avoid

It is tempting to reuse leftover carpet underlay, foam sheets, yoga mats or packaging foam. These materials are not designed for outdoor artificial grass and can cause issues. They may hold water, break down under sunlight and moisture, compress unevenly, or create odours.

Avoid materials that:

• Absorb water like a sponge and stay wet after rain.
• Crush easily and do not recover their shape.
• Block drainage across the concrete surface.
• Are designed only for indoor use.
• React poorly with outdoor adhesive or tape.
• Create a slippery layer beneath the grass.

The safest approach is to use underlay made specifically for artificial grass or outdoor surfacing. It may not be the cheapest-looking option at the start, but it is far less likely to cause problems once the grass is fitted and in daily use.

Choosing the right thickness and feel

Thickness matters, but it is not the only measure of quality. A thicker underlay can feel softer, but if it is too soft it may make furniture wobble, create visible indentations, or cause the grass to move underfoot. A thinner, denser underlay may be better for dining areas, walkways and spaces where chairs, tables or planters will sit.

Think about the main use of the area. A balcony used for morning coffee needs a different feel from a children’s play corner. A narrow side passage needs stability more than bounce. A family patio may need a balanced surface that is pleasant under bare feet but still firm enough for garden furniture.

As a broad guide, look at three qualities together:

1. Cushioning The underlay should noticeably soften the concrete, especially when kneeling, sitting or walking barefoot. It should not feel like a mattress or allow the grass to ripple.
2. Density Denser artificial grass padding usually gives better support under regular use. It helps the surface feel stable and reduces the risk of deep impressions from foot traffic or furniture.
3. Recovery When pressure is removed, the underlay should spring back rather than remaining flattened. This is important in areas used frequently or where children and pets play.

The best artificial grass underlay for concrete is not automatically the thickest one. It is the one that suits the use of the space, supports the grass properly, and works with the drainage and fixing method. Compare the 10mm underlay and 15mm underlay options according to the space’s height, comfort and furniture requirements.

Does artificial turf underlay help with drainage?

Artificial turf underlay can help with drainage if it is designed to let water pass through or move beneath it, but the underlay cannot fix a badly draining concrete base on its own. Before installation, the concrete should be checked to see where water flows and whether puddles remain after rain. If water already sits in dips, those areas may need attention before grass and underlay are fitted.

Drainage is one of the most important considerations on concrete. Artificial grass normally has holes in the backing that allow water to pass through. If the underlay beneath those holes is impermeable, the water has nowhere useful to go. It may spread slowly, sit between layers, or run towards an unwanted edge.

A drainage-friendly underlay helps by keeping pathways open. Some products have channels, perforations or a structure that allows water to travel. Others are made from materials that water can pass through. What matters is the complete system: grass backing, underlay, adhesive placement, concrete fall and drainage outlet all need to work together.

Adhesive can also affect drainage. If glue is spread in a solid layer across the whole area, it may block water movement. Many installations use adhesive around the perimeter and on joins, or apply it in a way that leaves drainage routes open. The exact method depends on the site and the products being used, but the principle is simple: do not create a sealed sandwich that traps water.

A practical drainage check

Before choosing underlay, it is worth doing a simple observation after rain or with a hose. You do not need specialist equipment for an initial check, just patience and a clear view of the surface.

Look for:

• Puddles that remain for a long time because these suggest dips or poor falls.
• Water running towards the house rather than away from it.
• Blocked drains or channels that need clearing before installation.
• Cracks or joints where water disappears and may affect the base below.
• Low spots near steps or thresholds where a raised grass and underlay system could create awkward levels.

If water has no sensible route away from the area, underlay alone will not solve the problem. In that case, the concrete may need remedial work, better drainage, or a different installation build-up.

Comfort, safety and everyday use

One of the biggest reasons to use artificial grass padding on concrete is comfort. A hard patio can be transformed into a more inviting outdoor area, especially for households that use the space as an extension of the home. Underlay makes the surface more pleasant for children sitting down, adults walking barefoot, and pets lying in sunny spots.

Comfort also affects how often the space gets used. A thin turf directly over concrete may look green, but it can still feel like a hard slab beneath your feet. Adding the right underlay creates a more garden-like experience, even where a natural lawn would be impractical.

For play areas, cushioning can reduce the harshness of minor trips and tumbles. However, it is important not to make unsupported safety claims. If the installation needs to meet a particular fall-height or playground safety requirement, you should use products designed and tested for that purpose and follow the relevant guidance. General domestic underlay can improve softness, but it should not be treated as a certified safety surface unless it is sold and installed as one.

For older users, a stable surface matters as much as softness. Underlay should not make the grass feel wavy, loose or bouncy in a way that affects footing. Edges, joins and thresholds should be finished neatly so they do not become trip points. A well-chosen artificial turf underlay adds comfort while keeping the surface even and predictable.

Matching underlay to different concrete spaces

Not every concrete area needs the same specification. The best artificial grass underlay for concrete depends heavily on the location and the people using it. A decorative strip, a family play area and a pet-friendly courtyard all have different priorities.

Patios and seating areas

Patios often need a balanced underlay. People want the surface to feel comfortable, but they also need chairs and tables to sit firmly. A medium-feel, supportive foam shockpad is often more practical than a very soft layer.

Furniture can create pressure points, especially under narrow chair legs or heavy planters. If the underlay compresses too much, the grass may show dents or become uneven. Using furniture with wider feet, moving items occasionally, and choosing a denser underlay can help maintain the finish.

The edges of a patio installation also deserve attention. Where grass meets paving, steps, doors or drainage channels, the combined height of grass and underlay must be considered. A thick build-up might look luxurious in the centre but become awkward at thresholds.

Balconies and roof terraces

Balconies and roof terraces need careful thought because drainage and weight are especially important. Water must be able to reach outlets, and no layer should block drainage channels or create standing water around the building. The underlay should be suitable for exposed conditions and should not interfere with the waterproofing system beneath.

On these areas, it is wise to keep the installation reversible or at least avoid anything that could damage the surface below. Adhesives, tapes and fixings should be chosen with care. If the balcony or roof terrace is part of a managed property, building rules or lease conditions may also affect what can be installed.

Comfort is still valuable, particularly if the space is used for relaxing. A drainage-conscious artificial turf underlay can make the area feel less stark while helping water move away. The key is to avoid treating a balcony like an ordinary garden patio, because the consequences of poor drainage can be more serious.

Children’s play areas

For children’s spaces, artificial grass padding is often a sensible addition. It makes the surface more forgiving for sitting, crawling and light play. It can also make the garden feel more usable throughout the year because the surface is cleaner than bare concrete and softer than a slabbed area.

Durability matters here. The underlay should cope with repeated movement, toys, small furniture and changing weather. It should not tear easily during installation or shift once fitted. Joins should be secure and positioned neatly so the finished surface feels continuous.

If the area includes climbing frames, swings or play equipment, seek products and installation guidance that match that use. A general underlay may improve comfort, but play equipment can introduce impact requirements that ordinary garden materials are not designed to cover.

Pet-friendly courtyards

Pet use changes the priorities. Drainage, cleaning and odour control become just as important as comfort. Underlay that traps liquid can quickly become unpleasant, so a free-draining artificial turf underlay is usually the better choice.

A pet-friendly installation should allow urine and wash water to pass through and move away from the surface. The concrete should have a route to drain, and the grass should be cleaned regularly with suitable products. Avoid absorbent foams or improvised padding because they may hold moisture and smell.

For dogs that run, turn and dig at surfaces, the grass and underlay must be fixed securely. Loose edges can be tempting for pets to lift. A stable, well-drained system will be easier to maintain and more pleasant for everyone using the space.

Paths, side returns and utility areas

Narrow concrete paths and side returns usually need a firm, practical finish. These areas often take regular foot traffic, bins, bikes or garden equipment. A soft underlay may not be necessary, and in some cases it can make the surface less stable than desired.

If comfort is less important, a thinner supportive underlay or no underlay at all may be suitable, provided the concrete is smooth and drains well. The main aim is to avoid creating edges that catch feet or wheels. Artificial grass can brighten these spaces, but it should not make them harder to use.

Preparing concrete before underlay goes down

Underlay performs best when the concrete beneath it is clean, sound and reasonably even. It is not a magic layer that can hide major defects. If the base has loose material, crumbling patches, oil marks, algae, sharp ridges or standing water, those issues should be addressed first.

Start by clearing the area completely. Remove furniture, pots, old adhesive, loose paint and anything that could stop the underlay sitting flat. Sweep thoroughly, then wash the surface if needed. Allow it to dry before using adhesives or tapes, unless the product instructions state otherwise.

Small cracks may not matter if they are stable and do not create raised edges. Wider cracks, loose concrete or moving sections need more attention. If a slab rocks, crumbles or holds water, covering it with grass will not make it structurally sound.

Pre-installation checklist

Before fitting artificial grass padding, check the following:

• The concrete is firm, clean and free from loose debris.
• Water flows away from the building and towards a suitable drain or edge.
• Any drains, inspection covers or channels remain accessible.
• The final height will not obstruct doors or create awkward steps.
• The underlay is suitable for outdoor artificial grass use.
• The grass, underlay, tape and adhesive are compatible.
• The layout avoids tiny offcuts in high-traffic areas where possible.
• You have planned where joins will sit before cutting anything.

This preparation stage is not glamorous, but it has a direct effect on the finished result. A clean, stable base helps the underlay lie flat, supports better bonding, and reduces the chance of movement later.

Fitting artificial grass underlay on concrete

The exact fitting method depends on the products used, the size of the area and whether the installation is permanent or temporary. Even so, most successful installations follow the same basic logic: plan the layout, secure the underlay, keep drainage routes open, then fit the grass neatly over the top.

Dry-lay the underlay first. This means placing it down without adhesive so you can check coverage, joins, levels and edges. It is much easier to adjust at this stage than after glue has been applied. If the underlay is supplied in rolls or panels, allow it to relax so it sits as flat as possible.

Cut carefully around drains, posts, corners and doorways. A sharp blade and measured approach will give a better finish than forcing pieces into place. Avoid stretching the underlay because it may pull back later and create gaps.

Once the underlay is positioned, it may be secured with suitable adhesive, joining tape or perimeter fixing, depending on the system. The aim is to prevent movement without blocking drainage unnecessarily. Joins should be close and even, not overlapped, as overlapping can create ridges beneath the grass.

The artificial grass is then laid over the underlay, positioned with the pile direction in mind, trimmed to fit, and joined where necessary. Many people prefer the pile to face the main viewing point because it often looks fuller from that angle. After fitting, the grass can be brushed up to settle the fibres and improve the appearance.

Common installation mistakes

Several problems come from trying to rush the job or using unsuitable materials. The most common mistakes include:

• Using indoor underlay outside, which can absorb water and deteriorate.
• Ignoring drainage, especially on enclosed concrete spaces.
• Applying adhesive as a solid waterproof layer, preventing water from escaping.
• Leaving ridges or overlaps in the underlay, which show through the grass.
• Choosing underlay that is too soft for furniture, causing dents and instability.
• Forgetting door clearance, so the finished surface catches when doors open.
• Failing to secure edges, allowing pets, wind or foot traffic to lift the grass.

A careful installation does not have to be complicated. It simply needs each layer to do its job without creating a problem for the layer above or below.

When underlay may not be necessary

Although underlay is useful in many concrete installations, it is not always required. If the concrete is smooth, well-drained and the area is mainly decorative, artificial grass can sometimes be laid directly onto the surface using the correct fixing method. This can keep the finished height lower and reduce cost and complexity.

Direct installation may suit narrow strips, low-traffic spaces or areas where furniture stability is more important than softness. It can also be suitable where the chosen artificial grass already has a dense, comfortable pile and the user is happy with a firmer feel. However, the grass will still reflect the hardness of the concrete beneath it.

There are also situations where underlay should be approached cautiously. If the concrete sits tight beneath a door threshold, adding underlay may create clearance problems. If drainage is already poor, adding another layer without fixing the underlying issue could make matters worse. If heavy items will remain in one place, a thick soft underlay may not be the most practical option.

The decision should be based on use, not habit. Ask what the space needs to do. If the answer is comfort, play value, warmth underfoot or a more garden-like feel, underlay is likely to help. If the answer is a thin, simple decorative covering for a sound slab, it may be optional. Read more about when underlay is needed before making the final choice.

How to compare artificial grass underlay options

Choosing the best artificial grass underlay is easier when you compare practical features rather than relying on a single product description. Different products may all be called underlay, but their behaviour outdoors can vary widely. Look beyond softness and consider how the material will perform after months of rain, sun, foot traffic and cleaning.

Start with outdoor suitability. If a product is not intended for external use, it is rarely worth the risk. Then check drainage. A good underlay for concrete should not trap water against the slab or prevent the grass backing from doing its job.

Next, consider the feel. Press the material by hand and think about the area’s use. For a seating zone, you want comfort with support. For a play area, you may want more cushioning. For a pet area, you may prioritise drainage and washability.

Also think about installation. Some underlays are easier to cut and shape than others. On a simple rectangle, this may not matter much. Around steps, posts, drains or curved edges, a material that cuts cleanly can save a lot of frustration.

Key qualities to look for

A strong artificial turf underlay for concrete should offer:

• Outdoor durability, so it can cope with changing weather.
• Drainage compatibility, either through its structure or material.
• Stable cushioning, giving comfort without excessive bounce.
• Good recovery, so it does not flatten quickly in regular use.
• Clean cutting, making it easier to fit around edges and obstacles.
• Compatibility with the chosen grass, adhesive and joining method.
• Low water absorption, particularly for pet or shaded areas.
• Appropriate thickness, based on door clearances, furniture and foot traffic.

No single feature should be considered in isolation. A soft underlay that holds water is not a good outdoor choice. A very firm drainage layer may be practical but less comfortable. The best option is the one that balances the conditions of the site with the way people will use the space.

What should you avoid when choosing the best artificial grass underlay?

Avoid choosing artificial grass underlay for concrete based only on price, thickness or a vague promise of softness. The wrong product can hold moisture, feel unstable, show ridges through the turf or break down faster than expected. A better approach is to choose an outdoor-suitable underlay that supports drainage, comfort and the finished height of the installation.

The first thing to avoid is absorbent padding. Concrete does not allow water to disappear into the ground, so moisture management is essential. If the underlay behaves like a sponge, it can remain damp long after the grass surface appears dry.

The second thing to avoid is excessive softness. It may feel appealing when you press it by hand, but a very soft layer can be impractical under chairs, tables, wheels or repeated foot traffic. Artificial grass should feel cushioned, not unstable.

The third mistake is ignoring the rest of the installation. Underlay is only one part of the system. If the grass has poor drainage, the adhesive blocks water, or the concrete falls the wrong way, even a good underlay may disappoint. Think of the project as a whole surface build-up rather than a collection of separate materials.

Finally, avoid creating a finished level that causes everyday irritation. If doors scrape, drains are covered, or the grass sits proud of neighbouring paving, the installation will not feel well considered. Measure levels before ordering materials and allow for the combined thickness of the turf and underlay.

Maintenance after installation

A well-installed grass and underlay system should be straightforward to look after, but it is not maintenance-free. Regular brushing helps lift the pile and prevent flattened traffic lanes. Removing leaves and debris also reduces the chance of organic matter sitting on the surface and encouraging moss or algae, especially in shaded areas.

On concrete installations, rinsing can be useful because water has a defined route to travel. For pet areas, more frequent cleaning is usually needed. Use cleaning products suitable for artificial grass and avoid harsh chemicals that could affect the backing, underlay or adhesive.

Keep drainage routes clear. If leaves block a channel or debris builds up near an outlet, water may back up beneath the grass. This can make the surface feel damp and shorten the useful life of the installation. A quick seasonal check is often enough for ordinary domestic spaces.

Furniture should be moved occasionally if possible, particularly heavy planters or items with narrow feet. This helps reduce long-term compression marks. If dents appear, brushing the pile and giving the area time to recover may help, although the result depends on the density of the underlay and the weight of the item.

Simple care routine

For most domestic concrete installations, a practical routine includes:

1. Brush the grass regularly to keep the pile upright and the surface looking even.
2. Remove leaves and debris before they break down into the fibres.
3. Rinse when needed, especially after pet use or spills.
4. Check drains and edges after heavy rain or seasonal leaf fall.
5. Move heavy furniture now and then to reduce pressure marks.
6. Deal with lifted edges promptly before they become a trip point or pet temptation.

These small habits help protect the underlay as well as the grass. They also make the space more pleasant to use day to day.

Practical examples for common projects

A small urban courtyard with cracked but stable concrete may benefit from a cushioning underlay that also supports drainage. The underlay can help soften the hard surface and reduce the visibility of minor imperfections. Before fitting, any loose material should be removed and drainage should be checked carefully, as courtyards often have limited outlets.

A family patio used for outdoor meals needs a more supportive finish. In this case, the best underlay for artificial grass on concrete is likely to be firm enough for furniture while still giving comfort underfoot. A very soft product could make chairs feel unsteady, so density and recovery matter.

A balcony installation should focus on drainage, weight, reversibility and building requirements. Artificial grass padding can improve comfort, but it should never obstruct outlets or interfere with waterproofing. If in doubt, the property owner, managing agent or a suitable installer should be consulted before work begins.

A pet area should prioritise washable, free-draining materials. Underlay that absorbs liquid is best avoided. The concrete should drain to a suitable point, and the grass should be cleaned often enough to prevent odour.

A decorative strip beside a path may not need underlay at all. If nobody will sit or play there, and the concrete is smooth, a direct installation may be adequate. This is why there is no single answer that suits every project: the best artificial grass underlay for concrete is always linked to use.

The final choice comes down to comfort, drainage and fit

The best artificial grass underlay for concrete is a purpose-made outdoor product that makes the surface more comfortable without compromising drainage or stability. For many homes, that means a good-quality foam shockpad or artificial turf underlay with a supportive feel, low water retention and compatibility with the chosen grass system. The right underlay should make the space feel more inviting while still allowing it to work practically in wet weather, under furniture and during everyday use.

Before buying, look closely at the concrete itself. Check where water goes, whether the surface is sound, how much height you can add, and how the area will be used. Underlay can make a patio, balcony or play space feel far better, but it performs best when the base is prepared properly and the whole installation is planned as one system.

If you remember one thing, make it this: do not choose underlay simply because it is soft. Choose it because it is suitable for outdoor artificial grass, right for concrete, comfortable enough for your household, and practical enough to stay dry, stable and tidy over time.