Materials for French drains are relatively inexpensive. You typically only have drainage pipes, pea gravel, fabric filters and catch basins. Then, add concrete and a sump pump to the costs for ...

Q: I live on a low-lying lot. My crawl space is always wet, even though I have a dehumidifier and a sump pump down there. People have suggested I use French drains; one said exterior ones ...

The modern version of the French drain is really an underground drainage system that directs groundwater away from building foundations to a downhill discharge area, a sump or to the street.