The reverse curve technology dates back over one hundred years. The first patent was taken out by George Cassen in June 23, 1908. This system has been modified in many ways over the past years by well over 100 venders.
Surface tension guides water into the gutter. The debris from trees and roof shingles is supposed to fall off with the water. This does not always happen and the aperture and gutter gets clogged and needs cleaning. Also, the aperture is access to wasps, birds and rodents to nest. Most of these systems are made of aluminum sheet metal of different gauges. Some screw into your roof decking which should be avoided.
What works, What works well and What doesn’t work:
We found all tested brands to be so similar that the only significant difference is in the marketing approach. When we attempted to obtain an interviews (by pretending to be a homeowner prospect ourselves) we were given the “hard sell” by each of the sales representative who called on us. As a Reviewer, I found this unpleasant and uncomfortable.
The home demonstration unit was very impressive, however. I was shown a demo unit with water running down a miniature roof and into the reverse curve product. It was a little amazing to see the water curve and follow the product. I asked what would happen if we increased or decreased the water flow and was told it wouldn’t matter, but the salesman refused to demonstrate this. On our own, we tested this and found that the demo only works at a predetermined rate of water flow. We concluded that in a heavy rain, water would run over. In our own test, it poured over. With a very light water flow (light rain) the water flow was insufficient to keep out leaves in our test.
They clogged on the outside and seed pods, pine needles and grit easily followed the water into the gutter. We concluded that this product is a poor product if a homeowner has a lot of trees, but would probably work fairly well if few trees, leaves, pine needles, etc. were present. However, the high pressure, “one-call close” sales presentation and the high pricing really turned us off.
Two additional notes, these products are not heavy duty and will easily dent or crush. They probably cost 1/10 as much to manufacture as the Micro-Mesh category, yet the pricing is as high or higher, presumably for sales commissions and profit. Also, we don’t want to imply that all sales people selling these products were high pressure, only the ones we met.