Regarding the use of guards to cover gutters
29 April 2006
A. The short answer as to whether or not to use any sort of gutter cover is yes and no. My attitude towards gutter covers as labor saving devices comes from a lifetime of wrestling with them in one form or another. I've put them up and I've taken them down. Every couple of years or so some new variation on the theme comes on the market and the claims are nothing short of miraculous. Let me march you through my reasoning and you be the judge.
Common roof guttering is almost designed to get clogged. Whether it comes in sections pre-manufactured or as coil-stock rolled through a forming machine on the back of a truck at the house, the results are basically the same. Your house has 55 linear feet of 5 inch gutter on each roof edge which is dropping rainwater into two, 2 inch by 3 inch downspout drains, then through a minimum of two elbows and finally onto or into whatever is there to carry the water away from the house.
The first flaw in the design is that you have a much larger drain-- the 55 feet of gutter-- dumping into a much smaller drain. You don't have to be a master plumber to see that is not headed for a lot of success. And the slope of the gutter as it is hu ng from the roof edge can almost never be the magic slope of 2%. A 2% downward grade, or 1/4 inch per foot of travel, is the slope plumbers set waste lines horizontally. At such a slope the water will slowly carry solids along with it. A greater slope and water runs too quickly leaving solid matter on the bottom of the drainage channel-- a flatter slope will allow things to settle to the bottom and cause an eventual blockage. That's what leaves and debris do in your gutters. Roof gutters are drains and obey the laws of physics just like all other drains. With a heavy rainstorm contributing as much as 400 gallons per hour to your gutters, you can see that it won't take much to cause this system to clog and overflow.
Screening, hardware cloth, or manufactured metal or plastic gutter guards placed over the open top of the guttering are an effort to slow the inevitable. They work fine in theory and the pictures in the ads showing the leaves and sticks skipping off of the guards and the water flowing unimpeded into the gutters seem magical.
What I've seen over time is while guards or screens prevent whole leaves and normal sized sticks from rolling into and clogging the gutters right away, what does get in are small bits of debris and broken leaves which lay on the gutter bottom and form a thick sludge that effectively stops up the works gradually. Then you have to remove the guards, clean and flush the gutters the old fashioned way, and put them back, or leave them off.
Too often gutter guards instill a false sense of security in the homeowners who have them and they become ignored. I see them in all sorts of disrepair and if any section should become loose or blow off, then the open section becomes a leaf magnet. Seed s find their way into the clogged gutters and soon, instead of a gutter hanging off your roof, you've got a flower box that overflows every time it rains. On the other hand I heard from folks who just love them. I think itís the proximity to a source-- t rees-- makes the difference and in your case you have no shortage of them so be forewarned.
If you decide go with a topper system get quotes for the complete cost of installation and then divide the cost of hiring someone to manually clean your gutters into the cost of the gutter guards and see how long it will be to reach the break even point- - keeping in mind that the screens or guards are not perfect and will require periodic sludge removal in any event. Some gutter cover companies offer a warranty to come and clean them should they ever become clogged. You can tell the system is clogged i f you begin to see a lot of black organic debris clinging to the front lip of the gutter suggesting that the gutter is overflowing during a hard rain.
The payback period-- when the cost of the guards finally equals all the money you've spent on hiring folks to do the cleaning-- could be as long as ten years. Where are you going to be in ten years?
Iíve said I could design a gutter system that would never clog but it would be so big and ugly that no one would want it hanging from their house. So we're sort of stuck.
Despite the advertising hype gutter covers are all pretty much the same animal-- a device to prevent debris from clogging your gutters. So if you decide that you are going to try them, then my suggestion is to go as inexpensively as you can. Some of the m can cost over $10 a lineal foot installed. Some do-it-yourself systems run about $3. a foot. It's your call.