The best sub-base for your artificial grass

Ensure your synthetic grass is nice and even with the right sub-base

artificial grass

by Marina Avraam |
Updated on

If you're tired of your grass changing from yellow to brown, only to spring up as a bright green when the weather is just right, then artificial grass might be just what you need. Synthetic grass is also great if you're looking to spruce up your outdoor patio, deck or garden, whilst keeping costs low.

However, as handy as artificial grass may be, the installation process is not as simple as you might think. Prior to rolling out the emerald green-ness that is your new lawn, it's important to ensure that you've created a stable, even and airtight base to increase the stability and durability of your grass - this is where sub-bases come in.

If you're planning on installing your grass on soil, then you'll need a layer of aggregates, otherwise known as a sub-base, for your synthetic grass to sit on top of. A sub-base is usually made of a type of stone, such as granite stone or limestone, which will provide your grass structural stability and can prevent sinkage in the case of footsteps or furniture being placed on top.

To help you figure out which sub-base is most suitable for your lawn, we've listed the best options on the market and answered a few commonly asked questions regarding fake grass installation and sub-bases.

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What is a sub-base?

A sub-base is a layer of materials used below your fake grass to ensure it is even and stable. Remember, a sub-base is only necessary for installing fake grass on soil - if you are installing your grass on a deck or concrete, then a sub-base is not required.

What is the best sub-base to use for artificial grass?

The two main sub-base materials include MOT Type 1 and/or granite or limestone chippings. For the best results, we recommend using a 50mm layer of MOT Type 1 and a 25mm layer of granite dust.

Sharp sand is also often recommended in replacement of granite dust, but keep in mind that this material can lead to drainage issues and is also prone to shifting underfoot.

Using a combination of MOT Type 1 and granite dust will help prevent drainage and levelling issues.

How do I install a sub-base?

First things first, you'll need to remove any existing turf from your garden. We recommend digging out around two inches of your soil and removing any stones and roots that might get in the way.

Next, after you've installed a weed membrane, it's time for the sub-base. Add a 50mm layer of MOT Type 1 and after the first layer is down, add up to 25mm of the granite dust. Then, make sure to even everything out using a rake or a screed.

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MOT Type 1

MOT Type 1 will serve as the first layer of your sub-base, and provides high strength and excellent load-bearing qualities.

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The best MOT Type 1 sub-base

UK MOT Type 1 Sub Base1 of 4

UK MOT Type 1 Sub Base

This bulk bag weighs a minimum of 800-100kg, so you'll be getting a lot of bang for your buck. The crushed pure granite or limestone sizes vary from 40mm down to dust and will provide a great, solid base for your new grass.

Key specifications:

Weight: 800-100kg

Used for artificial grass, driveway, patio and path sub-bases

Will cover 10sqm at 50mm thickness

MOT Type 1 Sub-Base Bulk Bag2 of 4

MOT Type 1 Sub-Base Bulk Bag

Another great option if you're looking to bulk buy, delivered in up to 850kg. This can be used for gardens, patios and driveways and also doubles as a weed suppressant which is always a plus when installing artificial grass. Note that the stones may vary in size

Key specifications:

Weight: 850kg

Used for gardens, patios and driveways

Weed suppressant

Tarmac Granular Sub Base Mot 1 Jumbo Bag3 of 4

Tarmac Granular Sub Base Mot 1 Jumbo Bag

Give your synthetic grass an even surface with this affordable specially blended sub-base material. The sizes vary from rubble to dust, and this mix makes a robust patio or grass sub-base.

Key specifications:

Weight: Varies due to level of moisture

Used for high quality paths and artificial grass

Covers approx 10.6sqm to 50mm depth

MOT type 1 Subbase, Bulk Bag4 of 4

MOT type 1 Subbase, Bulk Bag

This bulk bag is easy to compact and highly spreadable. Containing a mix of sizes from dust to 40mm, this will work wonders for drainage underneath artificial turf.

Key specifications:

Weight: 800kg

Covers up to 13.5sqm From 40mm to dust

Granite dust

A thin layer of granite dust will help prevent drainage issues and is especially recommended for houses with pets.

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The best granite dust sub-base

Tarmac Grano dust, Bulk Bag1 of 2

Tarmac Grano dust, Bulk Bag

Place this on top of your MOT Type 1 for the perfect artificial turf base, free from sinkage or drainage issues.

Key specifications:

Weight: 920kg

0-6mm in size

Travis Perkins Grano Dust Bulk Bag 6mm2 of 2

Travis Perkins Grano Dust Bulk Bag 6mm

High-quality granite dust with a minimum weight of 800kg. Reviews state this product is ideal for using under your synthetic grass and spreads easy.

Key specifications:

Weight: Minimum 800kg, but depends on moisture

Delivered and unloaded for you

Locally sourced product

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Sharp sand

In some cases, sharp sand can be used instead of granite dust as an additional layer on top of MOT Type 1. We recommend a 15mm thickness and smooth compaction for the evenest results.

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The best sharp sand

Sharp Sand bulk bag1 of 2

Sharp Sand bulk bag

Sharp sand aggregate can be placed on top of MOT Type 1 to increase stability and evenness. This can also be used for paving, rendering and general gardening use.

Key specifications:

Weight: 825kg

Can be stored outside

Vitax Sharp Sand2 of 2

Vitax Sharp Sand

If you're laying down turf on a smaller surface, getting your hands on a 20kg bag is a great idea. The lime-free coarse sand will improve drainage and overall durability of your turf.

Key specifications:

Weight: 20kg

Can also be used for laying paving and patio slabs

Often used to top dress lawns

How to install artificial grass:

Marina Avraam is a Commercial Content Writer for What's The Best, and also writes for Grazia, Heat and Closer. She has a passion for psychology, reading and fashion writing.

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