The most common drainage issue faced by homeowners is what to do with the water that comes from the downspouts. This area is frequently ignored by homebuilders and left to the homeowner to deal with. The idea is to take the water and divert it away from your foundation to keep it from getting into the basement and/or damaging the foundation of the home or ruining the expensive landscaping. An important thing to note is that most ordinances require you to drain the excess water to a drainage ditch, storm sewer or dry well. As a general rule, it is against code to drain it onto someone else’s property. You will want the exit end of your drain to be at a lower elevation than the area that you are draining‐it doesn’t have to be a big change in elevation‐even a few inches should be enough to keep the water flowing.
To complete this project, you will need to purchase a downspout adapter that converts your downspout (a 2” x 3” or 3” x 4” rectangle are most common) to a 4” inner diameter circular shape. These are commonly available at most hardware and home improvement stores. You will also need solid pipe and angular crushed stone between ½” and 1” in size with few or no pieces smaller than that, not pea gravel.
What you should know before you start
The ability of any flexible pipe to carry the weight of the soil and traffic loads is due to the composite strength of the pipe-backfill structure. As weight is applied the pipe flexes to equalize the load while the surrounding backfill forms a structural arch that transfers the load around the pipe and into the bedding. The final load-carrying capacity of the pipe-backfill composite depends on the quality of the pipe, the bedding, backfill material and the installation.
To drain your downspout away from your home you will need to dig a trench that leads to a dry well, drainage ditch or storm sewer and add 2” of crushed stone to the length of the trench. Next attach the downspout adapter to the downspout—many times the downspout will end in an elbow, you can leave this on or remove it to get an installation that is tighter against the house. (See images 1 & 2)
You can secure the adapter using a couple of sheet metal screws. Next, expand the pipe to the required length and attach FLEX-Drain® to the adapter. It should snap in tightly and will be difficult to remove. (See images 3 & 4)
Finally, position the pipe as necessary and cover with 2” of crushed stone (See images 5 & 6)
Once you have covered the pipe with gravel, you may cover the entire installation with the excavated dirt and tamp down.