The Importance of Adequate Compaction When Installing an Artificial Lawn

Installing artificial grass is a relatively straightforward process.

Planning

Planning your project is the most important step. You will need to work out how much artificial grass you’ll need and which accessories you’ll need.

Artificial grass comes in either 2m or 4m widths, and lengths of up to 25m. The grass has a directional pile (which means all the blades lean to one side). When you roll out a piece of grass, the blades will either lean away from you or towards you, never left to right. For the optimum look, try to make sure the blades are leaning towards the house or seating area.

So to plan this, you’ll need to draw out a scale diagram of your garden. Use our helpful Project Planner. Think about the layout of each roll of grass and draw rectangles for where they will go, onto your diagram.

But, of course, to ensure success, it’s vitally important to ensure that each step of the installation process is completed correctly.

We have published several articles over the years to help both DIYers and professional installers to get the best results from their artificial lawn installations.

In our latest installation article, we’re taking a closer look at some of the reasons why it’s important to ensure that both the laying course and sub-base of your artificial lawn are adequately compacted.

Compaction is a key step and one that, if you don’t get it right, may fail your artificial lawn.

The groundworks are vital in any successful installation and we always say that you can have the best quality artificial grass money can buy, but if the installation isn’t completed correctly then you’re likely to have issues with your fake lawn in the years to come.

Experienced DIYers are certainly capable of carrying out their artificial grass installation, but we do normally recommend using an experienced professional.

If this is the route you’re going to take, then you may find it useful to search for your nearest SayGrass-approved installer.

They’ll be able to take care of everything from start to finish, so you don’t have to lift a finger. Of course, it’s likely to cost you more than a DIY installation, but it’s also likely that your artificial grass will prove to be a much better long-term investment, as a professional installation should perform better than a DIY installation.

Laying Artificial Lawn on Uneven Ground

If you have uneven ground, you risk water pooling in certain areas which can reduce the lifespan of your fake lawn. You also risk the joins not lining up which will not only look unsightly but can also be a trip hazard. If the seams do line up but the centre of the ground is not even, someone could fall over a dip and hurt themselves. There’s also the added risk of weeds coming through if no weed membrane has been installed.

But even if you’re considering using a professional, it’s still useful to know about the installation process, and the information in this article will give you good background knowledge about a key aspect of artificial grass installation.

But even if you’re considering using a professional, it’s still useful to know about the installation process, and the information in this article will give you good background knowledge about a key aspect of artificial grass installation.

Sub-Base Aggregates

When it comes to choosing the aggregates for your sub-base installation, you have two options available to you.

You can either choose MOT Type 1 or granite/limestone chippings.

In most circumstances, we recommend that you use Type 1, compacted to a layer between 50–100mm deep.

For the majority of garden installations, 50mm of Type 1 will create an adequate sub-base.

For heavy use, in public areas, using a layer compacted to 100mm deep is recommended as it will have the capability of withstanding frequent heavy use.

Under some circumstances, choosing a sub-base comprising granite or limestone chippings is recommended.

The great thing about these chippings is that they are a ‘washed aggregate’. This means that they do not contain any fines. An aggregate diameter of between 10mm and 20mm works best.
If you are a pet owner, then we highly recommend that you choose this type of aggregate. This is because it is a permeable sub-base that will allow liquids, in this case, urine, to drain through the turf and then through the sub-base without leaving behind any nasty odours.
Another example of when we would recommend this permeable sub-base is if your garden has drainage issues. If there are areas of your lawn that are boggy for a large part of the year, then use granite or limestone chippings.
Likewise, if your artificial grass will be receiving large amounts of surface water run-off, from a large patio, for example, then again, go with a permeable sub-base.
However, if you have neither a pet nor drainage issues in your garden, using Type 1 is the best way to go.

Laying Course Aggregates

For the laying course, we highly recommend 25mm of granite or limestone dust.

Whether you use granite or limestone doesn’t matter, just use whatever is locally available. In some parts of the country, you’ll find it easier to obtain one type of aggregate over the other. In the early days of artificial grass installation, many contractors would put down a layer of compacted sharp sand before laying the fake turf. This works fine for block paving, but it’s not quite the same with artificial grass. The major difference is that artificial grass allows up to 52 litres of water to drain through its perforated backing per square metre, per minute.

Always Use a Vibrating Plate Compactor, Where Possible

Both the sub-base and the laying course require adequate compaction to prevent dips and undulations from appearing in your artificial lawn.

To do this, you’ll need a vibrating plate compactor. Every professional contractor should own one of these, but for DIYers, they can easily be obtained from your local tool hire shop.

Never Compact in Layers of More Than 50mm

We recommend that your sub-base material is compacted to a minimum of 80% of its compaction capacity.

A typical vibrating plate compactor will only achieve 80% compaction when the sub-base material is no more than 50mm thick. Therefore, you should only ever compact 50mm of aggregate at a time. So, in the case of a 100mm sub-base layer, you’ll want to compact this into two separate layers to achieve the desired result.

Compact Laying Course Material When Wet

Water also has an important role to play in the compaction of the sub-base material.

After importing and levelling your sub-base material, be it type 1, chippings, or the granite/limestone dust laying course, we recommended saturating the aggregate.

By doing so, you’ll further aid the compaction of the material.

Of course, there is a fine line between not enough water and too much.

You’ll want to ensure that the water penetrates the entire depth of the sub-base material from top to bottom, but you’ll want to avoid flooding the surface.

Don’t Attempt to Compact Your Sub-Base on Waterlogged Earth

Of course, the first step in a typical artificial grass installation is to excavate the existing turf to expose the subgrade, or soil, ready for the sub-base installation.

Before you begin importing sub-base material, the subgrade, or earth, should not be saturated or waterlogged. If it is, it will severely hamper the compaction of the aggregate.

If you are faced with a saturated subgrade, you should allow it to dry out before spreading the sub-base material. Failure to do so could mean inadequate compaction and issues will include an uneven sub-base further down the line.

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Mohammed Khan

Just left us a 5 star review

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From start to finish, SayGrass provided an outstanding service. The team was professional, knowledgeable, and incredibly helpful throughout the entire process. They took the time to answer all of my questions. The installation was completed to an exceptionally high standard, with great attention to detail and a flawless finish. The transformation is amazing—the lawn looks lush, natural, and has completely enhanced the appearance of my outdoor space. It's also low maintenance, which has been a huge bonus. The installers were punctual, friendly, and left everything clean and tidy when they finished. Their workmanship and customer service exceeded my expectations. I would highly recommend SayGrass to anyone looking for high-quality artificial grass and a reliable, professional installation team. Five-star service from a company that truly takes pride in its work!

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Great job would recommend

google

We couldn’t be happier with the job Saygrass have done. From the initial enquiry through to completion, Niti and the whole team were fantastic. The workmanship is excellent, and the finished result has completely transformed our garden. The team were professional, friendly and hardworking throughout, taking real pride in what they were doing. They also left everything incredibly clean and tidy at the end of each day, which was really appreciated. Communication was great from start to finish, and the whole project ran exactly as promised. I wouldn’t hesitate to recommend Saygrass to anyone looking for artificial grass. Excellent service, excellent quality and a genuinely professional company. Thank you to Niti and the team—we’re absolutely delighted with the result!

google

Very happy, highly recommended.

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Nitti was very response to calls and queries and always happy to tweak things to get the best result for me. There was an issue with part of the 1st install but Nitti was on hand to ensure it was resolved and that the final result was great.

google

Thoroughly recommend Saygrass. Reasonable quote and great service. The labourers worked so hard and cleaned up beautifully. 10 our of 10.

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10/10 got the job done quick. Kids love playing out in the grass! Would definitely recommend

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These guys were local to me and got lots of recommendations, so went with them for a concrete base. From start the finish the process was easy and top job. So helpful and nothing is too much for them. Really good company and I would definitely recommend

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Fantastic work. Very professional, clean and tidy

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Really good quality service