I always see in details the note “filter fabric”. But in most cases I never see it specified and I work for a contractor that uses the same fabric for every application and it ends up clogging rather quickly. So I did some research and here’s what I found from usfabricsinc.
Anytime drainage is a factor like in french drains or below patios a non-woven, needle-punched filament such as US100 or US120 is required. The US120 seems to percolate faster.
If drainage is not a concern and you are looking to provide stability and prevent aggregate migration, a woven slit film such as US200 is required.
Now I’m beginning to understand why all our french drains clog. Any input on this?
PS: I would never use fabrics in garden beds. Horrible idea.