Trench rock is used as a drainage tool. In proper trench construction, there is a required means of drainage at the bottom of the trench. The drainage allows for water or runoff to be diverged so that the trench itself doesn’t fill up with water. A popular material used for this type of watershed is shaped trench rock.
Trench rock is a form of gravel that is poured into the bottom of the trench and then leveled. It spans the length of the trench so that the surface of the trench is able to evenly distribute the water shed into it. Though many people use any type of gravel they can find to form their trench rock structure, the best type to use is a medium-sized rock base so there is enough room between the rocks to disperse the water.
In a watershed trench, the rock should fill up about half of the trench’s height. Next, a permeable gutter system that is able to distribute water through itself, such as a cloth-covered drainage hose, should be laid on the rock. This system should then be completely covered in more rock, with the drainage hose being let out at either the road to a drainage basin or to a lower tract of land that isn’t used often.
It’s important to cover the drainage hose with at least 2 inches (5 cm) of trench rocks so that any water that enters the hose does so evenly and so the hose doesn’t become plugged. Once the trench rocks cover the drainage hose, another layer of permeable cloth should be laid out across the width and should span the length of the trench. This acts as a sediment filter for the trench rock. Then the cloth should be covered with at least 4 to 6 inches (10 to 15 cm) of dirt that can be somewhat compacted or tamped down to avoid erosion.
The purpose and dimensions of the trench are going to determine the amount of trench rock needed. Due to the fact that most people don’t have the necessary amounts of gravel and rock readily available, the rock will in most cases have to be ordered according to the amount needed for the job. Calculating the depth, width, and length of the trench will give a basic idea of just how much trench rock is needed.