How many rows of openings are required for perforated tile?

The requirement for arranging perforated tile specifies that a system should have two rows of openings. This configuration allows for efficient drainage and optimal water flow, which is essential for maintaining the proper function of a subsurface drainage system. In a two-row system, the perforations facilitate adequate infiltration and help prevent clogging, allowing for effective management of groundwater and reducing the risk of backflow or saturation in the surrounding soil.

Having one row might not provide sufficient drainage capacity, while three or four rows could complicate the design unnecessarily and lead to excess expense without providing additional benefits. Therefore, the two-row standard strikes an ideal balance between effective drainage performance and practical implementation within the standards set by the Illinois regulations.