Garden Advice

What Sub-Base to Use for Artificial Grass

Artificial grass installation can be a rewarding investment. Although it comes a bit more expensive compared to real turf, once laid, it requires a minimum amount of maintenance. After you’ve chosen from the wide variety of types of grass available, the only thing left to decide is what sub-base to use for artificial grass. You will find our recommendations and some further useful information below.

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So, if you:

  • are about to install artificial turf and want to know more about each step to follow;
  • wonder about what the best sub-base is for synthetic grass;
  • want to know if you could lay Astroturf directly onto a hard surface;

Then, this post is just for you.

What is the best sub-base for artificial grass?

The sub-base of your Astroturf is the layer placed directly on top of the soil. It creates the perfect conditions for the laying course, which is usually installed on top of the sub-base. 

Your artificial grass base should be either MOT Type 1 or 20mm stone clippings. MOT Type 1 is a granular material and it provides the stronger base because of its increased compaction level. Within the makeup of this material there are more finer, smaller particles.  Although they allow sufficient water drainage, they are generally non-porous, which makes them unsuitable if you already have drainage issues or a pet, who will be using the turf. 

The best sub-base for artificial grass for domestic applications is the 20mm stone chippings. They are usually granite or limestone and allow for liquids to drain quickly and easily through them, to the lower layer of your base. They provide a strong enough base that easily will hold up through your everyday family life, as they are similar in endurance and size. 

Is a sub-base necessary?

  • If you have decided to replace your real turf with artificial turf you will definitely need to install a sub-base for the artificial grass. It cannot be placed directly on top of your current turf or the soil.
  • If you are installing it on a firm existing surface, such as your decking, or a paved or concrete area, then an artificial grass base is not needed. These surfaces provide enough structural support to be able to handle it.

How much sub-base aggregate should you order?

Depending on the intended usage there is a minimum recommendation for optimal depth for your sub-base:

  • Domestic applications – require a minimum of 50mm (2”);
  • Commercial or public areas (schoolyards and playgrounds) – require between 75mm to 100mm (3” to 4”).

MOT Type 1 and stone chippings are both supplied in ton bags or loose loads. To calculate how much aggregate will you need for the sub-base you first need to know the size of your required base. For example, if your lawn is going to be 50mm thick you will need one ton of sub-base for every 10 sq.m.  If your lawn is 75mm thick you will need 1.5 tons for every 10 sq.m.

Also depending on how much sub-base you need, you can decide whether to purchase it in ton bags or loose loads. Even though ton bags are named so, they are usually less than a ton – about 850kgs, depending on the substance inside them. You will need to check with your local store and decide how many exactly you would need to order. If your area is larger it may make more financial sense to order a loose load with the aggregate of your choice. This is usually delivered to your home and you only need to move it to the intended area.

Sub-base is done. What now?

Once you’ve laid your sub-base your work is not done. It is best to follow it by a layer of sharp sand or grano. Granite or limestone dust are usually referred to as grano and you will need a 25mm laying course of it. Grano is often successfully substituted by sharp sand. 

A final step prior to laying the turf can also be laying a weed membrane, which will help keep all weeds and real grass from growing between your artificial grass strands.

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Do you need professional help with laying artificial turf?

Well, not everyone’s got the skills and time to go through the process of making significant changes to the landscape of their green space. And in this case, the steps to follow, in order to install synthetic grass correctly, can be rather overwhelming, to say the least. So, this is where Fantastic Services can be of your assistance by providing you with a professional turf laying service, done by experienced and multi-skilled landscapers. The pros have got the know-how and the right tools to install expertly both real turf and artificial grass in your back or front garden. Just contact us anytime and we’ll handle the rest.

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  • A sub-base should be MOT Type 1 and 20mm stone chippings – granite or limestone. 
  • You don’t have to lay a sub-base if you plan on installing your astroturf on top of a decking or a concrete/paved area. 
  • If you are replacing your real turf, you will definitely need a sub-base. 
  • Remember to finish with a grano or a sharp sand layer, followed by placing a weed membrane under your artificial turf.


Image source: haiyee

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