Ask The Engineer About Gutter Guards For Pine Needles

Pine needles are one of the biggest challenges for all gutter guards and gutter screens. There are approximately 35 types of pine trees in North America with needles ranging from as short as about 5/8 of an inch to as long as three or four inches.

In fact gutter screens don't stand a chance as the tiny needles easily penetrate them and go into the gutter. I once had a homeowner determined to build a screen to keep his pine needles from getting into his gutter. He took the finest mesh screen he could find and made three layers of it. When I looked at the screen I was amazed that the pine needles actually managed to penetrate the screen and clog his gutters. I wondered if the product I was recommending would do the job. Read on.

In a similar vein of design we find the foam type gutter inserts. They too are a mesh and I hope I don't have to tell you what happens with them. I once found a product that did keep the pine needles out. It was a screen with louvered slots. The only problem was that after a few years the pine needles built up on top of it like a thatched roof. Again I wondered if the product I was recommending would do the job of keeping out the pine needles and letting in the rain water. Read on.

Then there are the mesh filters. Manufacturers of some of these products acknowledge that debris will build up on the tops of the filters and it does. What they recommend is that by using a telescopic extension pole and a specially designed brush that can be used to clean the tops of the filters. I must admit I've used brushes to clean the product I recommend, but it's easy for me to see where the accumulation of debris is and it's easy to see that I've removed it. How can I see on top of the gutter to see where the debris has clogged the mesh? And if I just brush every foot of gutter, how do I know that enough of the debris has been removed? Can you think of some questions about how to maintain this product? Maybe they have all the answers but I haven't seen them published yet. What's going to remind me to brush them? What about the exposed fascia—what's protecting it? Just too many unknowns!

Let's look at the solid helmet or topper type of covers. From an engineering point of view, there are  four general types of designs:

1. Single fin which serves as one long louver guiding the water into the gutter. If there are pine needles laying on the tops of the gutter guards or gutter covers many of the pine needles usually line themselves up horizontally to the roof edge. I guess we could figure out why this is so but as it rains they generally stick to the surface of the gutter guard just as the rain does. Since there is only one long longitudinal fin collecting the water, any length of pine needle can easily adhere to the fin or louver and go into the gutter in sufficient numbers to clog the gutter as well as the opening of the gutter protector.

2. Single fin with trough is very much like the first type—only difference is that it has a trough located below the gutter lip to screen out debris. But, since this trough is below the gutter lip, then how is this trough cleaned? Plus the openings in the troughs are usually large enough to let many full sized pine needles pass on into the gutter.

3. Single fin with screen on the top. This is a hybrid mixing two designs with the same result. The screens clog yielding the same product as described in number one above.

4. Vertically louvered gutter guards with two rows of louvers instead of one long fin. Actually it's two long fins broken up every 3/4” to keep out all debris longer than 3/4” in length. And for anything that size to get in, it has to hit the opening exactly right. Twenty one years of experience proves that this design keeps pine needles of all sizes from getting into the gutter in sufficient numbers to clog the gutter. And the two customers I recommended this design to who previously had screen type of devices have never called to claim failure of the product.

Do the louvered collectors clog with pine needles? Yes they do and it is very easy to see from the ground—even on second floor or higher gutters—where this is happening. And guess what? It's real easy to use a telescopic pole and brush to remove the accumulated debris. And if the homeowner forgets about his gutter for a few years and the louvers really clog, it takes a bit more effort but the result is the same—louvers are easily cleaned and the gutter covers function perfectly again.

Exposed fascia? Not in this case. The rear edge of the gutter protector sides in under the roofing shingles—not nailed or fastened to the roof in any way which could cause leaks—to protect the fascia from exposure to weather. In summary, screens, filters, and mesh products are going to trap pine needles and either clog inside the gutter or clog the openings of the gutter guard device and block water from getting into the gutter. From an engineering stand point a solid top gutter guard is the way to go. However, the openings of the gutter cover must be limited in size to exclude the largest amount of pine straw or pine needles. A design that integrates two rows of louvers of limited size will have the best opportunity to keep sufficient debris from entering the gutter that could clog it. The last consideration is ease of cleaning the gutter protection device as all gutter covers will clog with heavy pine straw conditions. Again, the clogs are easily visible from the ground with the double row louvered system and easily cleaned from the ground by the homeowner with a telescopic pole and brush.

To find out more about the best gutter guards--self cleaning gutters-- please visit

Richard Kuhns B.S.Ch.E. President and CEO of R.K. Industries manufacturer of the Waterloov® Gutter Protection System. To learn more please go to
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