What Is the Standard French Drain Size? A four-inch diameter perforated French drain pipe running five to ten feet is considered standard sizing for most applications around your home. If your home experiences heavy amounts of water accumulation or has very saturated soil, you might need to install a larger diameter pipe.

Pipe Size According to foundation repair experts, a typical French drain system in a residential home has a four-inch diameter. But if the area experiences a high volume of water, it might be suitable to install six or eight-inch pipes.