Why should 8 oz. commercial filter fabric be used in a French Drain
The picture provided shows a French Drain trench being lined with an 8 oz. commercial grade filter fabric that is rated for 90 GPM through 1 Sq. Ft. of fabric. This allows for fast drainage of surface and ground water during even the heaviest rain events. The heavy 8 oz. fabric will not decompose allowing sediment to plug the saw cut corrugated pipe. All the stone around the pipe is wrapped with this fabric, making it impossible for contamination to enter into the French Drain.