A 1-percent slope means that it drops 1 foot vertically for every 100 horizontal feet. Example A 50-foot French drain that starts at the correct depth of 18 inches would be 24 inches deep at the ...

French drains are typically covered with pea gravel and a fabric filter to prevent dirt from clogging the drain line. They are also called trench drains, perimeter drains or curtain drains.

If you happen to have some pea gravel you're not sure what to do with, you can always use it to improve water control in your French drain. Since pea gravel is very prone to slipping and being ...

The classic French drain is simple - just a trench filled with gravel, with sand on top. It allows excess water to percolate through the sand and gravel, eliminating the puddles. The modern ...