Changes

==Planning Considerations==

==Planning Considerations==

Both modular systems require a bedding of angular clear stone to permit infiltration, and provide a foundation for the installation:  

Both modular systems require a bedding of angular clear stone to permit infiltration, and provide a foundation for the installation:  

*Plastic modules usually have a parabolic shape to resist the load above. The spaces between the rows of modules are filled with clear stone to support the overlying infrastructure.

*Plastic modules usually have a parabolic shape to support the load above. The spaces between the rows of modules are filled with clear stone to support overlying structures.

*Concrete modules are often box shaped and can, in some circumstances, be employed without any additional cover. However, a minimum of 20 cm cover is recommended for most applications. Where this cover is planting soil this can support turf grass. Greater planting soil depths are required to support more deeply rooting plants like perennials and shrubs (45 to 60 cm) and trees (85 to 100 cm).

*Concrete vaults are often rectangular-shaped and can, in some circumstances, be employed without any additional cover. However, a minimum of 20 cm cover is recommended for most applications. Where this cover is planting soil this can support turf grass. Greater planting soil depths are required to support more deeply rooting plants like perennials and shrubs (45 to 60 cm) and trees (85 to 100 cm).

==Design==

==Design==