Wondering whether gutter screens, filters and covers actually work is a common question for anyone who regularly cleans or hires someone to clean their gutters.  The ultimate best answer to this question will depend on the asker’s expectations and perception of what a gutter protection system should accomplish.  To fully answer the question and show the reasons why different expectations might result in different answers, we will first do a quick review of the various types of gutter protection (screens, filters and covers.)

Roll mesh screen

Roll mesh screen

Rolled Mesh Screening

This simple roll of screen barely qualifies as being considered gutter protection.  I have yet to see it serve a useful purpose.  The concept is that you roll out this material over your gutters and your problem is solved.  In reality, you have an unruly material, either plastic or thin galvanized metal, that wants to take it’s own shape.  Inevitably, it curves and twists so that there are still exposed areas of the gutter.  Additionally, the holes or spaces in the screen are larger that the area of solid material, so most anything except the largest oak or maple leaf is kept out.  Since most debris still enters the gutter, you still have to clean them with regular frequency.  This leads the another major negative of these screens – once you have removed then to clean underneath, you can never get them back in the same or even a reasonable position.  They commonly need to be thrown out.  I usually like to be balanced and cover both pros and cons of an item, but for this screening, I cannot find any legitimate reasons for using.

Vinyl Snap-in Covers

Snap In screen

Snap In screen

These screens come in 4 foot sections and are intended to slide under your roofing material on one side and snap into the rim of the gutter on the other side.  The main surface has a molded or stamp cut hole, often diamond shaped, for water to flow through.  They are incrementally better than roll screening in that they are more rigid and sturdy.  An expectation of 4-7 years useful life before they are excessively warped or brittle is reasonable.  Similar to the mess but a little more successful, they allow much debris to pass through and thus, still require cleaning.  Again, just like the rolls, the need to remove and replace a screen when cleaning gutters makes the job more difficult or expensive.

Hinged Mesh Covers

A hinge that allows easy lifting is what separates this screen. While these are similar in efficacy to snap in screens, they have one advantage – when performing the inevitable cleaning under them, rather than pulling them completely off you can swing them open.  This partially reduces the annoyance and extra work of cleaning screened gutters.  However, they are not without their own shortcomings.  They have larger openings than vinyl snap-in screen, so more debris gets inside.  Most problematic, the convex arch of the screen forms a damn between the gutter and the roof, trapping fallen debris that would normally continue its way down and off the edge to the ground.  Because of this, if not kept frequently maintained, considerable overflow can happen.

Solid, Reverse Curve Covers

Reverse curve gutter cover - 1908 patent

Reverse curve gutter cover – 1908 patent

Reverse curse gutter covers date back to 1908 (see 1908 patent office diagram above.) There are two primary types of these covers, with all the other distinctions being significant only in the eyes of the manufacturers.  One type of reverse curve gutter covers is incorporated into the gutter itself.  The other type is strictly a cover that attached on top of existing gutters.  Both employ the principle of surface tension to roll water around the top, then rounded side of the cover and eventually into the gutter itself.  At this level of gutter, you are now looking at what can truly be considered a gutter protection “system”, not just a mere screen.  The most expensive options lie within this category.

For the most part, these covers accomplish their objective of transferring water into the gutters.  Yet, they sometime fall short, not only in the transference, but with some secondary issues too.  Grime, sludge and mildew commonly accumulate on the leading edge of the cover, inhibiting the flow of water into the gutter.  Additionally, surface tension has it’s practical limits, and quite often in rains that are not all that heavy, the tension will break and water will shoot straight off the cover, much like a car rounding a corner too fast.  This in effect defeats the entire purpose of having gutters in the first place. Finally, water is not the only item that follows the surface tension – smaller debris follows the water right into the gutter.

Unfortunately, these covers are either not removable or very hard to do so, creating a difficult situation when the inside of the gutter has finally accumulated too much debris.  Some of this is alleviated by having larger downspouts which allow more of the collected debris to flush underground, but even with those, the problem still occurs.

Foam Inserts Filters

Foam Gutter Insert

Foam Gutter Insert

Foam Inserts are one of the more recent gutter protection systems to enter the market, first appearing less than twenty years ago.  They are also some of the first methods to employ true filtering versus covering.  A penetrable, open cell, polyether, wedge fills up the majority of the gutter, leaving only a channel for the rainwater to evacuate to the downspout.  Foam filters employ the principle of displacement – there is nowhere for the debris to go because the gutter is mostly filled with this material.  Inserts have proven to do a very solid and affordable job of keeping debris out of gutters and are effective with a wide spectrum of debris, from needles to leaves.  Yet they too have some weak spots.  While ultra fine particulate can wash through the filter, slightly larger particles, such as composition roof granules can get stuck in the top level open cell structure, requiring blowing or brushing off.  Certain debris types, such as cottonwood tree seed clumps can attached to the rough top surface of the filter and mat down, creating spots where overflow can occurred if not removed.  Additionally, if roof debris is neglected and left roof top too long, organic matter can start to take roof in it.

Micro-mesh Filters

Micro mesh filter

Micro mesh filter

The most recent development in gutter protection, micro mesh filters actual use a filtering screen that differs from older methods primarily in its material used and physical strength.  The mesh used is exceptionally fine, medical grade stainless steel.  Despite being fine, it allows water to penetrate well.  The fine mesh also creates a much smoother top surface than other filters such as the foam, helping debris more easily blow or rinse off.  Additionally, the mesh is attached, in the best examples of this style, onto extruded aluminum, creating a very strong frame.  These filters work well with a wide variety of debris.

The main shortcomings of micro-mesh systems involve some of those faced by other systems.  While most debris typically blows or rinses off, there are areas where some may still remain, creating the need to sweep off the accumulated debris.  Excessive amounts of fallen roof granules can sometimes be most troublesome, require brushing off.  Also, certain roof locations (discussed below) can result in excessive amounts of rainwater flowing to a concentrated section of gutter, possibly resulting in overflow in heavier rains.

The Perfect Gutter Protection System

So, you might ask, which is the perfect system.  Maybe several, maybe none.  Very simply, if you approach the entire category of gutter protection with the expectation that you will never have to maintain anything above your gutter line again, there is a high likelihood that you will be disappointed.  You will likely feel that the product or system did not deliver on its promises (or what you may have assumed were its promises based on unrealistically hopeful expectations.)

Tempering Expectations in Light of Real World Factors

To be pleased with the system you choose, you need to understand the difference between clogged gutters and overflowing gutters (clogged is an internal blockage inside the gutter that causes water to dam up and spill over, overflowing refers to water not entering the gutter due to issues with the screen, filter, or cover.)  You additionally need to realize that both your roof and the top of your gutters (which in effect act as an extension of your roof top) still need to be periodically cleaned of debris.  No system in the world can prevent debris from falling out of trees and if for no other reason than your roof’s sake, you need to keep it maintained otherwise moss and other issues will start.

Under-Guttered Houses

Additionally, realize that some houses and roofs were designed with very little thought to the gutters.  If they could find a place to fit gutters on, they were considered adequate.  But in reality, many roofs are under-guttered.  There are locations where too much roof field (the main area of a roof section) drains down into a relatively small amount of gutters.  In heavier rains, even clean, open gutters might overflow in such spots simply from a lack of capacity.  However, if gutter protection is installed on such a home, it may be easy to just assume the protection system is not working.  Plus, certain systems might exacerbate the problem slightly, making them overflow in rains that are heavy, but not torrential.

Trouble Spots

Trouble spots are similar to inadequate gutter in that the end result can be more water than what is fair to expect the gutter to be able to handle.  The most common trouble spots involve areas where upper roofs drop their rainwater onto a lower roof, forcing a small section of gutter to receive excessive water.  Roof valleys are also problematic as they too direct a disproportionate amount of water (that is additionally traveling faster) to a small gutter section.

Environmental Surroundings

Finally, consider the type of debris in your yard (and your neighbor’s too – tree debris can travel much farther than most realize.)  A landscape that exclusively has very large leafed deciduous trees might be able to get a way with a simple screen while ones with smaller debris might be best suited by a micro mesh filter.  Some debris that is easily dealt with by one system might be problematic for another.  Debris that tends to be extra thin, subject to forming a mat (such cottonwood seed clumps) can be more problematic for filters than screens or covers, while pine and fir needles can easily defeat simple screens and reverse curve covers.

Ultimately, if you tend to view gutter protection as a way to help considerably reduce one aspect of home maintenance while not being a perfect, end all solution, then you will likely be pleased with your decision.

Final Thoughts

Always make sure that gutter protection makes a good financial sense and provides adequate peace of mind.  It is wise to compare how often you could pay for your gutters to be cleaned versus the cost of gutter protection.  Certainly there are other reasons to have protection beyond just cost savings, but it makes sense to be familiar with the pay off period.  Additionally, some house locations can benefit from a few less glamorous options, such as larger downspouts or downspout reducers coupled with a knee level downspout clean-out.  While the gutters still will need regular cleaning, some of the frequency is reduced and the most common clog location is brought down to ground level.

If you need help sorting through all this information, we are here to help.  We can help you decide whether you are best forgoing gutter protection all together or if it looks like a wise option for you, help determine which system is best for your particular needs.  Finally, we will help you have real world expectations, so you are happy with your decision.  Call us today – 503-590-9274.