There is a design very similar to this on the market called leafguard. The concept is the same in the drawing you shared, with water's surface tension and adhesion clinging to a curved surface as it wraps around into the gutter with the leaves and other debris going over the top and not into the gutter. It's a great idea, but the reality is it only works with very light rainfall. If it starts raining hard or really coming down, the rainwater shoots right over the top along with the leaves. Leafguard often has a display at home shows and such, with the design working nicely. Ask the representative to increase the water flow to mimic heavier rainfall, and if they actually do it, water ends up on the floor. I have yet to see a design like this function as intended with water flow rates of a downpour thunderstorm, like 2.5 inches of rain in an hour. That sounds like a lot, but storms like this are a common occurrence nowadays for me here in middle tennessee. The amount of rain coming off an average size roof is astonishing. For example, a 2 inch/hour heavy thunderstorm on a 1000 square feet of roof area will have about 1240 gallons of water enter a gutter. (here's how I got that number: 1000 square feet x 144 inches in a square foot = 144,000 square inches. 144,000 divided by 231 (there's 231 cubic inches of water in one gallon) = 623 x 2 (for the 2 inches of rain) = 1240 approximate gallons.
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Jason Vath wrote:In the permaculture design manual, Chapter 7 - Water.
there's a brilliant diagram of gutters (see the circled one in the attached pic.)
Does this gutter design actually exist?
IF so, where can it be purchased?
Any experience with it?
There are variations on the top left design. We have something called a leaf eater that has worked well for us. http://rainharvesting.com/product/leaf-eater-original/ They do need to cleared out periodically and I still get leaves in my gutters. There are other similar options but it seems to me that the bigger your gutters and the more fall you have the better.
Our home is three years old, and we live in the west coast of Vancouver Island, (also known as the "WET Coast"). We endeavored to install a leaf free system, as we have a lot of fir trees around that love to clog gutters. We went with formed on site, professionally installed, large gutters, and purchased a perforated metal plank system that goes under the shingles but on top of the gutter...helpful but not to the extent I expected. Biggest problem, crud coming off the asphalt shingles (the granules) and significant needle incursion.
In my opinion, the biggest issue is lack of sufficiently steep slope in the gutter...but in hindsight, I would have eliminated the downspout and gone for chains or the basket dispersal method shown on the top left.
I suspect the circled design would not perform on a steep roof, or in heavy rainfall.
Lorinne Anderson: Specializing in sick, injured, orphaned and problem wildlife for over 20 years.