Subsoil drains should be surrounded with what material?

Subsoil drains are designed to control excess water in the soil, preventing water accumulation that can lead to various issues like structural damage or erosion. Surrounding subsoil drains with coarse gravel is essential because this material facilitates efficient water flow through and around the drain. Coarse gravel provides sufficient void space that allows water to move freely towards the drain, effectively helping it to perform its function.

Additionally, coarse gravel has a larger particle size compared to other materials, which reduces the likelihood of clogging by silt or smaller particles. This property ensures that the drainage system remains effective over time by maintaining a clear path for water to exit the soil. When properly installed with coarse gravel, subsoil drains can significantly improve drainage efficiency and protect infrastructure from water-related damage.