When constructing your new arena it’s important to build a solid and free draining base layer, using the correct construction methods and the recommended materials. Without this foundation to your arena you are likely to experience poor stability when riding, the arena may be subject to regular flooding and it may even reduce the longevity of your riding surface. Most of the common arena problems that we see are a direct result of either the base layer, or membrane not performing as it should.
What is the Foundation Stone there to do?
The base stone in your outdoor riding arena construction serves three main purposes:
- To provide a firm and stable base for your ménage surface
- To allow water to pass freely from the arena
- To provide a reservoir away from the surface that will hold excess water until it can be dispersed, either into the ground or the drains
What Stone should I use for the base layer?
For a riding arena base layer we recommend a clean and preferably washed hardstone, such as carboniferous limestone or granite. Clean railway track ballast with the fines screened out is also a good option, but this product is not always readily available. Rounded gravel, road planings or demolition hardcore should never be used. The base layer stone should be angular in shape as this allows enough space in between each stone for water to drain efficiently, and for the stones to interlock which provides you with a firm foundation.
Using a hardstone, such as carboniferous limestone, will prevent the base layer stones breaking down during use, which can cause blockages and prevent adequate drainage. Hardstones come in various sizes, a 20/40mm works best when using a geotextile membrane to separate your arena surface from the base layer. Alternatively, you can also use a 5/20mm stone in conjunction with a blinding layer which replaces the need to use a geotextile membrane.
Should I use a stone blinding layer or a geotextile membrane?
We highly recommend the use of a blinded stone system to separate your riding arena surface from your base layer. The system comprises the use of a 4/20mm hardstone for the drainage, with a smaller stone, such as a 2/6mm laid on top. The blinding layer is then compacted to provide you with a level base on which to lay your chosen equestrian surface. The advantage of a stone blinding system is that it will not block or hinder drainage.
Geotextile membranes are recommended by many contractors as they are quick and easy to install. However, they can become blocked by organic matter, such as leaves or droppings, which will prevent the arena surface from draining correctly. If you do decide to install a membrane instead of a stone blinding layer, make sure it is a suitable quality.