In the weeks of rainy weather after the flood, I kept the entire problem area covered with a huge tarp directing water into the trench I’d carved leading to the driveway. Once the weather finally cleared, it was time to install a foundation drain.
DEVISE A PLAN The goal of a drain is always to move water from one place to another, and a traditional French drain incorporates an under- ground perforated pipe to provide an easy escape for landscape runoff. My plan was to apply the principles of a French drain beneath the backyard patio at my house, while incorporating some redundant features to ensure as little rainwater as possible could get past the drain system and contact the foundation walls. Having observed that the tarp covering the backyard had pre- vented further leaks during some particularly nasty downpours, I reasoned that if I were to “water- proof” the same area using a per- manent drain system, then I’d have addressed the issue. This problem area began at the end of a concrete stair landing and
extended past the end of the house to a driveway covered with crushed rock. My idea was to seal the end of the buried pipe at the concrete landing and divert water by sloping the open end toward the driveway, where the pipe will “daylight” a few feet past the cor- ner of the house and bleed the runoff downhill toward the street. When researching French drain installation, I was surprised to find so much conflicting advice. For example, some installers suggest you cover the pipe with a drain sock to prevent silt from clogging the pipe’s holes. Other installers say it’s crazy to cover the pipe with a sock, because silt will clog the sock fabric and prevent water from passing into the pipe. After considering all the infor- mation, I came up with the system you see in this article which bor- rows what I considered the best ideas from several sources. For you “French drain purists” out there, note that I’m not dubbing this project a traditional French drain, so you can keep your Twitters holstered. This is an “exterior foundation drain” installed to prevent any water whatsoever from getting to my basement. During the planning phase, you should call 811, the national “Call Before You Dig” number. It’s designated by the FCC to protect homeowners from the injuries, expenses and penalties caused by digging into underground utilities. This is a free service but it might take couple of days for the serv- ice-person to get to your house, so get your name on the list. TOOL LIST Wheelbarrow Garden hoe Shovel (square- and round-point) Mattock Hand Tamper Drill with spade bit Utility Knife
Have a plan to move and store all the displaced materials.
The work site contained two banks of pea gravel to decorate the patio. I used tarps to isolate the pea gravel from the dirt and drainage rock and keep the materials organized.