Channel Drain for Roof Runoff?
Hi there,
I’m very intrigued by the idea of replacing the decrepit, leaky gutters on my home with some type of ground solution. I’ve found articles like the following to be very inspiring: https://www.greenbuildingadvisor.com/article/ground-gutters
My question is: can a similar thing be achieved using channel drains installed at the dripline of the roof? The only thing I’m looking to manage is roof runoff and aesthetics where this would need to be applied are not a concern. I am in zone 6 and can drain to daylight no problem.
An example of what I mean by a channel drain is here: https://www.ndspro.com/products/drainage/channel-and-trench-drains/spee-d-channel-drains.html
Thank you so much!
Brian
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Brian,
Trench drains typically rely on a sloped hard surface on either side to channel water into them. Unlike the ground gutters discussed in the article you linked to, it would be very difficult to situate then so that water coming off the roof hit the narrow drain in all conditions, and didn't just dissipate into the nearby soil.
The other problem with moving the collection of roof water from the eaves to the ground is that it means relying on the cladding much more to deal with both wind blown rain, and splash-back. I did an experiment a few years ago with my shed and added a small length of gutter just over the door. This allowed me to walk in without getting wet, but I soon noticed that even with very deep overhangs the siding on each side was wet from grade to about 18" up. I soon replaced the small length with one that ran the full distance.
Also, in CZ6 you will have situations where there is water running off your roof but freezing when it gets to ground level (sunny day in the winter) which could lead to a mess.
Seamless gutters installed properly with the correct drip edge at the edge of the roof will help a lot with gutter leaks. You also need things pitched properly and enough downspouts installed. I've seen plenty of incorrectly installed gutter systems with either little or no pitch, which reduces the amount of water they can carry to the downspouts, or insufficient numbers of downspouts so the gutter itself fills up and over flows. Another classic problem is gutters that are clogged due to lack of cleaning.
I used to have a sort of "channel drain" like you describe (but more of a long and narrow dry well really), and I had a lot of splashback like Malcolm saw with his shed, and I also found wind would often blow a significant amount of the runoff water back against the sides of the house. I added a regular gutter and that solved all the problems. It's better to collect the water immediately as it comes off the edge of the roof, then use a gutter system to direct the runoff to wherever you want it to go.
Bill
Thanks for all of the input, everyone! It sounds like seamless gutters leading to some type of catch basin and piping is the best route to go. I really appreciate the help!