A layer of gravel (see below for size recommendations) should be placed in the trench to a minimum depth of 1 inch.
What size gravel is best for drainage. French drain gravel size guide getting started. It may be deeper, as necessary, to ensure minimal slope. It is what all the other gravel sits.
Crushed stone/gravel #5 is 1 inch or smaller in size. Pea gravels are good for french drainage systems as the size is perfect for the project. This material is perfect for road and paver basees.
For a french drain without a perforated pipe, opt. Gravel size and rock type is something that homeowners do not think about until it is too late. Gravel is installed in three layers, with different gravel sizes for each.
This gravel is usually larger and is made to create a solid foundation and encourage drainage. This material is a great choice for railroad and driveway projects. #3 gravel should be used for the topmost layer as it provides a strong base and drainage for your.
Every type of driveway is going to need base gravel. Is #57 gravel good for drainage?