Artificial grass is becoming an increasingly popular solution for those looking for a low / to no maintenance grass aesthetic for their outdoor space, whether that’s a garden, sprawling landscape or even a roof terrace! Artificial grass means no mess and no mowing or upkeep; however, preparation is key during the install to ensure a perfect and lasting finish. What is laid under the artificial grass is arguably the most vital step of the entire laying process. In this blog we will explore what a sub-base is, and what are the best materials to use.
What is a sub-base for artificial grass and why is it so important?
A sub-base is the layer of aggregates installed beneath artificial grass to create a level and stable surface. It is laid directly on top of the earth (or subgrade) and is vitally important in providing strength and stability as well as drainage. By using the correct sub-base you can avoid sinking or settlement in the finished artificial lawn and prevent the pooling of rainwater or other liquids – especially important for pet owners!
Which sub-base should I use?
Artificial grass is wonderfully versatile and can be laid on a wide range of surfaces, however these won’t necessarily aid a high quality finish. For example, laying on to concrete or decking will rarely allow for suitable drainage, will be uncomfortable underfoot / to touch, and the grass can compress over time into unseen dents or gaps. Similarly, laying directly on top of soil does not provide a stable surface or prevent weeds growing through your newly laid artificial lawn.
Your choice of sub-base will very much depend on the area you are laying artificial grass within. The two most common sub-base materials are granite and MOT Type 1.
Chippings of granite, or sometimes limestone as an alternative, are larger stones that then provide excellent drainage below your artificial turf. Granite chippings are arguably the most common sub-base used across private landscapes where the lawn is not going to be subject to heavy use and is especially popular with pet owners. The chippings are readily available and will not require much levelling so are ideal to use where natural turf pile was previously laid.
MOT Type 1
MOT Type 1 consists of crushed limestone, granite or concrete, MOT stands for Ministry of Transport as Type 1 is often used in the construction of roads. The particle sizes are smaller than chippings meaning this type of sub-base can be firmly compacted down and is ideal for commercial settings where the lawn will be experiencing heavy use. Mot Type 1 is excellent in avoiding sinkage, especially when raising areas, for example when filling in old ponds, and is also ideal in new-build landscapes that haven’t yet had time to compact. MOT Type 1 can fill large areas very quickly and provide a very stable surface.
Preparation is key when laying artificial grass:
Regardless of which sub-base you opt for, we always recommend laying a Geotextile membrane below it. This will avoid any re-growth but also provides a barrier to separate your sub-base from the subgrade, ensuring the materials do not mix and ultimately avoiding sinkage in the future. We also recommend laying a minimum depth of sub-base of 50mm, or 75mm for areas that will experience heavier use.
How can I guarantee the perfect finish?
Once you have installed your sub-base, it is best practice to lay another geotextile membrane on top followed by a laying course which provides the flat surface on which to lay your turf. A popular laying course option is ‘Grano’, short for ‘Granolithic’ which is comprised of very fine limestone or granite dust. This provides further drainage below your artificial grass and can be compacted to provide a perfectly flat finish.
Alternatively, a more superior option would be to lay Drainbase tiles on top of your sub-base. This innovative system provides tiles that click together to form a flat surface delivering the perfect finish for your lawn, while also holding and supporting rainwater permeation in to the ground.
Drainbase Tiles in action:
Drainbase buffers up to 30 litres of water per square metre of lawn, increasing the grass’ durability. The tiles have anti-slip pins that ensure the turf stays in place and have patented connections between each tile that allows them to expand and shrink, meaning they are suitable for all weather conditions. We recognise that artificial grass doesn’t appeal to everyone, here at ECCO Products we are trying to make artificial turf more sustainable through Drainbase tiles which are made from recycled materials, are fully recyclable themselves, hold and buffer water and require less excavation into the ground. Drainbase can be applied on top of various substrates and provides the perfect finish to ensure your artificial lawn lasts the test of time.
Check out more information on Drainbase here…