Are the two lines of pre-drilled holes in 4" french drain pvc pipe enough holes, or is it better to drill another line of holes, maybe between the 2 lines?
-
2Hello, and welcome to Home Improvement. The holes were put there for the usual purpose; any reason why your application would be different?– Daniel GriscomCommented May 15, 2019 at 20:10
-
2Yep. Water doesn't need much space to drain, and those holes add up to a lot of space. Unless your particular case has a concentrated area of high volume, go with it the way it is.– isherwoodCommented May 15, 2019 at 20:52
2 Answers
The holes in the pipe are enough; drilling more would weaken the pipe. The important thing with French drains is to have a good bed of gravel around the pipe for several inches. I like using a sock on my pipes to prevent the fine gravel from falling into the holes. No need to drill more holes the ones that are there are more than enough.
As Isherwood says, pipe socks are good. You can also put down landscape fabric before the gravel bed and pipe and then fold the top of the landscape fabric over the top. This helps keep the gravel from filling with dirt.