How to Extend a Downspout
Connecting downspouts to buried drainpipes can help dry out a wet basement and soggy lawn
Rain gutters and downspouts provide an efficient first step in controlling roof runoff. But if the rain or melted snow channeled off the roof isn't carried far enough away from the house, it will collect against the foundation wall or footing and seep into your basement or crawl space. One surefire way to avoid such water-related problems is to connect the downspouts to a series of buried drainpipes that lead far from the house.
Installing drainage pipe is a straightforward job that any homeowner can handle. It's typically done in three phases: digging the trench, laying the pipe and backfilling with soil.
The drainage pipe used for extending downspouts is nonperforated Schedule 40 PVC pipe with 4-inches-diameter. Some jobs will also require flexible drainpipe, which is invaluable for getting around obstacles or following uneven terrain. For our installation, we used it to snake around a few large boulders we couldn't pry out.
Along with the drainage pipe, you'll need an assortment of PVC elbows, T-fittings, couplings, adapters and other specialty fittings that allow you to connect together the pipe sections. Also, purchase a 16-ounce can of PVC primer and PVC cement for gluing together all the parts.
Lay out the Trench
Use a string and 1x2 stakes to lay out the trench. Pound in two stakes 4 feet from the house and directly in front of each downspout. Place other stakes spaced 8 feet apart in between. Tie the string to the downspout, then stretch it out and around all the stakes.