gutter guard filled with debris causing clog

Gutter Guards Performance Problems

We have all heard that wonderful promise, “Install our Gutter guard and never clean your gutters again”.   I have over 20 years of roofing and exterior remodeling experience. Anyone who has been out in the field and is truly experienced in the gutter business, knows first hand that if you want your gutters to continue to flow and there is a high volume of debris, it is  going to require maintenance; regardless of what type of gutter protection you install. Companies make all sorts of statements in order to increase the sale of their products and when it comes to gutter protection, there is no shortage of false claims and over-promises..   I have come to realize that due to their attempt to be maintenance free, mainstream gutter protection devices come with “collateral issues” and performance short-falls. The gutter-flow and tree debris dilemma is genuinely a difficult predicament and there is no solution that keeps gutters flowing and requires no maintenance.   Think about it, if you have a thin channel of water and you drop a whole-lot of debris on it, it is going to eventually require maintenance to keep it flowing. Streets need to be cleaned to keep sewers from being clogged, shower drains need hair to be removed or the shower will fill up, and gutters are no different. Sure, devices can be installed in order to improve performance and decrease maintenance, but regardless of the claims those companies make, they will require maintenance in order to keep them flowing and they all will have collateral issues to deal with.    In other words, gutter protection devices may decrease maintenance but the more you try to eliminate maintenance entirely, more often you will be trading one problem for another. For example, I can create a gutter cover that will keep 100% of the debris out of the gutter forever, the problem is that due to physics and the “natural laws”, if I design a device that keeps all of the debris from entering the gutter, the fact is that I am going to have the “collateral issue” that I am also keeping some or all of the water from entering the gutter; especially in very heavy rains.   If you had a gutter guard device that allowed you to never clean your gutters, you will not be happy with the performance; especially at the times when you really want it to perform. Due to the fact that the problem is real, all gutter guard devices either require maintenance to keep them flowing, or they have collateral issues trading maintenance for lack of performance and functionality. Mainstream gutter leaf guard devices can be assembled into different categories, which are listed below with the collateral issues that they cause.


  • Gutter Covers, Hoods, or Helmet-type devices.
  • Gutter Flat Screens and Recessed Screens with Large Openings or Micro opening
  • Gutter Sloped Screens With Large or Micro sized Openings
  • Plastic or Metal Do-it Yourself Gutter Screens


Gutter Covers, Hoods, or Gutter Helmet-type Devices.

These are typically smooth sheet (thin) metal leaf guard devices, with a rounded profile, that cover most of the gutter opening except for a thin open slot at the outer edge. They perform on the principle that the water will hug or conform to the metal and flow into the thin horizontal length-wise slot or opening.   The concept is that leaves are supposed to blow over and past the gutter while the rain water flows into the slot. The most common collateral issue with these, is that the rain water does not actually hug and follow the metal, rather the metal acts as a ramp and especially in very heavy rains, the water shoots past the entire gutter as if you had no gutters at all.    When the metal is brand new and very clean, these devices work as well as they will ever work because the rain water hugs or holds to the metal best when the metal is brand new and very clean; however once the metal gets dirty, the water releases much sooner. Installers of these leaf guard devices have explained to me that in order to improve the performance, they will revisit the device annually to wipe-clean the outer sheet metal curve  so that it once again will possess the qualities that promote functionality giving the water the best possible chance to “hug”; because if the water does not hug the metal, the speed of the flow causes it to cascade past the gutter opening. As an added complication, the gutter guard installer must fasten these leaf guard devices at the exact recommended angle in order to get optimal performance, and since the slope of each roof is different, slight applicator angle error can cause the water to release easier and bypass the gutter.  These devices typically intersect the roof and get fastened to the roof which can affect roof warranties, cause roof holes and leaks, and in colder climates create a “first to freeze” zone at the bottom of the roof since cold air passes both over and under the metal device. These have been known to contribute to ice jams and back-ups. One other collateral issue for these devices, is that animals and bugs love the completely dry protective shelter that these hoods provide. They are solid covers therefore, the underside is a dry safe place for wasps, hornets, bees, birds, and other animals to take up residence and multiply.   Contractors attempting to rectify issues have explained that they can no longer get near the gutter because the stinging insects are prevalent and especially dangerous when the worker is perched on a ladder. My personal opinion is that the bottom edge of the roof is the most important area of the roof because it receives all of the roof water and I would never want to install a gutter guard or anything that decreases the slope of the roof at this critical juncture. I know that keeping gutters flowing is important, but it is not so important to me that I would ever attempt to solve a clogging gutter problem with any leaf guard item that affects or even just touches the roof; it’s not worth it..   These gutter guard devices create an almost horizontal shelf and although the metal is smooth, leaves and debris get wet, sticky, and do collect and remain piled-up on them. The opening that allows the water to flow into the gutter is thin, but it is also a long opening. Leaves pine needles and other tree debris are also thin therefore they can, and will, fit into the opening and enter the gutter. If a leave were laying on one of these gutter hood type of devices, and water flowed down the roof, the water can wash the leave right into the thin opening because the leave is thinner, so I do not understand how claims can be made to “never clean your gutters again”. Once these gutter guard devices clog up, they require tools, fasteners, skill and a lot of time and expense to disassemble them in order to clean them out.   Architects have called me wondering if I know of any simple or quick techniques to clean them without too much skilled labor; but I have no tricks.


Gutter Flat Screens and Recessed Screens with Large Openings or Micro-Openings:   Gutter Screens with large openings have long been used to decrease maintenance, but in order to make the openings large enough to accept the fast moving rainwater from the roof, they also had to make the holes large enough to allow thin debris to enter the screen hole and the  gutter lengthwise or remain stuck in the screen openings. To compensate for this problem, the industry has added or gutter guard microscreens laminated to the large-opening screens, to keep debris from entering and clogging the gutter or to keep debris from getting caught in the screen.   By adding the gutter  micro mesh, they have traded one problem for another; sure debris no longer enters the gutter but neither does the water when it is flowing from the roof at a high rate of speed which occurs during heavy rain. Gravity is required to pull the water through the gutter micro screen but when it is raining hard, the water is flowing off of the roof with a high degree of horizontal speed so most of the water will overshoot of the micro-screen and bypass the gutter entirely before gravity has a chance to pull it through the screen.   Many gutter guard manufacturers have recognized that the rain water has a propensity to bypass these flat leaf guard devices so they additionally have further recessed the gutter screen down into the gutter by a half inch or so. By recessing the screen, the water does have less chance of bypassing the gutter because it is impeded by the half inch lip which creates a little pond of water atop the gutter screen giving it more time for gravity to have its effect at pulling it into the gutter, however recessing the gutter screen also traps the leaves and debris on top of the screen. So by recessing the screen they have allowed it to capture more of the water (not all of it) but they have also trapped the leaves and debris which lay on top of the screen making a sort of mushy cereal mat.   Once the water hits the debris mat that is laying on top of the screen, it once again skips off of the surface and cascades past the gutter making it seem like there are no gutters at all. Flat gutter screens are installed over or onto both the front edge and the back edge of the gutter with screws so one other issue with flat screens, is that when thy get covered with debris, wind can push the water back towards the roof drip edge and cause water to back-up over the fascia creating leaks behind the fascia and possibly into the building. Most gutters are sloped, therefore at the high end of the gutter, there is hardly any portion of the fascia extending up higher than the gutter so with a flat screen covered with debris the assembly acts as a ramp for wind to blow the water back up under the drip edge, over the fascia and into the soffit.    Such is often the reason for peeling paint. From a roof leak point of view, it is a poor design to trap water atop the gutter. In colder climates the screen freezes and becomes a sheet of ice creating a propensity for ice jams, ice back-ups, and problems. Combine this condition with poor roof ventilation and insufficient insulation, and you have a real recipe for winter lower-roof edge problems often improperly blamed on the shingles. One other issue with gutter flat screens is that they have joints between each section of screen. When one gutter screen edge sags (for whatever reason) due age, improper installation or the weight of over-laying wet debris and the pounding of the water, the adjacent screen may remain supported and straight; therefore rain water on top of the system can rush laterally (sideways along the top of the gutter screen) and rush into the the sagged space between the two screens carrying large amounts of surface debris into the gutter.


Sloped Screens With Large or Micro sized Openings   Previously, I discussed the repercussions of gutter screens with large sized openings and the fact that the larger size opening receives the water well, obviously because the opening is larger, but of course the larger size openings also receives more debris.  When debris gets stuck in the opening, (often diamond shape openings) maintenance can be annoying because nobody wants to hand-pick each piece out one by one from the many thousands of holes. The concept of installing the screen on a slope is intended to decrease the volume of debris or leaves that will remain laying on the screen.   It is common to see sloped screens sold in white or brown plastic with a micro-screen laminated to one side. The collateral issue is that due to the fact that the solid portion (area with no openings) is substantial in proportion, and rib areas of the solid portion (usually every 8 inches or so) have no holes at all, there is often much of the rain that, even in light rain,  simply follows the sloped guard and bypasses the gutter altogether. I spoke with a gentleman this past week who explained that he recently purchased and installed the plastic sloped  gutter screen, only to learn that due to the fine openings in the micro mesh, heavy rain simply used the screen as a ramp and shot entirely past the gutter. With the high speed of the rain water flowing from the roof, gravity simply did not possess enough force or time necessary to pull the water through the gutter micro mesh openings.   After 6 months of this disappointing experience, he removed and returned the gutter micro mesh; the big box store provided him with a refund even though they had previously been installed and were slightly used.


Plastic or Do-it Yourself Gutter Screens    These gutter screens typically have large openings like that of chicken-wire or mesh, and are installed usually with a pressure fit in a semicircle or “hump” configuration at the opening of the gutter.  They can be fastened but are usually just laid in place and set into the recessed edges of the gutter. Since the openings are large, they generally do a pretty good job allowing the water to enter the gutter while they are still clean.  These systems are notorious for blowing out of the gutter in winds, or collapsing down into the gutter; especially due to snow loads. Since they are usually “loose-laid” in place, when one small section blows out of the gutter, its weight usually eventually pulls the rest of it out of the gutter also.  The leaf guard screen openings are fairly large so debris still gets caught in them. I cleaned gutters for customers for many years, and these flimsy screens did not decrease the amount of maintenance required. Each time I showed up at the customers home, I usually found the screen to be collapsed down into the gutter covered with wet leaves.   On occasions when I arrived at the home and the screen was in place, I was typically frustrated by the fact that all of the gutter screen openings were filled with lengthwise tree debris hanging in the screen so even if i entirely removed the screen, I still had to pick each piece of debris out of each aperture of the gutter screen; which was very time consuming.   Sometimes, I’d lift the gutter screen to put my hand inside the gutter, only to find that once I lifted one portion out of the gutter, there was a domino effect, and the rest of the gutter screen would come rolling out of the gutter with the entire gutter screen ending up on the ground. Once I cleaned the gutter and painstakingly cleaned the items out of the gutter mesh openings,  I often found that the gutter screen had “memory” and permanently had assumed its collapsed shape, making it impossible to reinstall back to the original shape. The used gutter screens were almost impossible to re-install properly because they had a memory of wanting to return to the collapsed shape they had taken for so many months. After years of gutter clearings, I determined that these leaf guard devices did not decrease maintenance at all, they were actually just a nuisance that made the regular gutter clearing job far more difficult, frustrating, time consuming and expensive.  If they had been fixed in place with fasteners, it was even more time consuming to maintain.


In conclusion, when you require an outdoor thin flow channel  (gutter) to continue to remain open and free flowing, in an environment of wind, rain leaves and tree detritus,  regardless of the gutter guard device, maintenance will be necessary. Devices and gutter guards can help to decrease the frequency of maintenance required, but they can also add difficulty to performing that gutter maintenance.    The more you attempt to install a “maintenance free” device, the greater the chance that you are trading gutter maintenance for some other negative issue; usually functionality and gutter performance. If you understand and accept that gutter maintenance will be required, you might be less likely to install a gutter guard device that requires a professional, tools, fasteners, and a lot of time to disassemble in order to maintain. Accepting that gutter maintenance is a reality, will position you to be able to choose a leaf guard product that will actually perform as best as possible under the circumstances.  In a perfect world we would be able to install a leaf guard and then forget about it forever, but due to natural laws of gravity and physics, there is no perfect gutter solution. When it does com time to maintain, it is highly frustrating to the person performing the gutter cleaning, if faced with a need to disassemble a complicated gutter guard device. Such, greatly adds to the cost of maintenance and therefore should be taken into account. So when you are deciding on the right gutter guard, accept the fact that maintenance will, at some point, be required and install one that is easily cleaned requiring no complications, tools, or fasteners.  In short, contractors and experts in the field agree that if you try to keep all of the debris out of the gutter forever, there is a great chance you will also be keeping the water out of the gutter. Oh yes, and if you like to hang your Christmas lights from the front edge of the gutter, make sure you choose a gutter guard appropriately because some of them inhibit such.


Alex O’Hanley


Debris laying on gutter guard

Above picture shows leaves laying on a smooth metal hood; for months

The recessed screens to accept more water, but the recessed area also collects more detritus.

Gutter Screen Fail Debris Covering Top

It is easy to see how the device can cause water to blow back over the fascia, under the drip edge and into the soffit causing a leak or peeling paint

Clogged hood or helmet style

 Clogged Gutter Guard Cover

When the helmet-style gets dirty, the water no longer hug; there are bees inside

Gutter Guard Cover Bees Wasp Nest

This picture depicts the helmet style removed, see the end-cap of the hood still in place, the birds enjoyed the dry safe shelter.

Helmet removed bird nest

This owner decided that the best place for the gutter hood was out at the curb, see the clean lower course of roof shingles where removed?  I hope they caulked the resulting roof holes

Gutter Guard Cover in Trash

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