How to Pick the Right Gutters for Your Cedar Roof
Updated: Apr 13, 2020
While we all recognize the importance of roofs, we rarely give a thought to gutters. They may not be the most glamorous fixture on your home's exterior, but are nonetheless critical to protecting your siding and foundation from water damage. And for gutters to work correctly, they must be large and durable enough to handle the volume of water coming off your roof, which can be surprisingly large. When just an inch of rainfall falls on an average-sized roof, this equates to 1,900 gallons of water that your gutter system must deal with.
In this guide, we'll show you what to look for when buying the best gutters for cedar roofs, including gutter type, shapes, sizes and materials.
Two basic types of gutters are available: seamed and seamless. We'll discuss each in detail below.
1. Seamed Gutters
Seamed, or sectional, gutters come in 10-foot segments fastened with hangers to the fascia board of your house. To connect them, you can either snap them together using joiner pieces or overlap them. You can complete a seamed gutter installation on a normal-sized home in a single weekend, assuming you have a reliable ladder and someone to help you out.
Seamed gutters and their peripherals — which include gutter guards, downspouts, corners, etc. — are available at most home improvement stores and come in vinyl and a variety of metals. Vinyl gutters are heavy, so you cannot paint them, but on the plus side, they can withstand corrosion, fading and rusting. Metal gutters, on the other hand, are relatively lightweight. Copper gutters, however, are significantly heavier and more expensive than the alternatives and may cost 10 or 20 times more than metal or vinyl.
The main advantage of seamed gutters is that they're DIY-friendly and affordable. Furthermore, if one segment gets damaged, you can take it out and replace it without messing with the rest of the system.
The most significant disadvantage is that they sometimes leak at their seams, usually due to the accumulation of debris. The stock colors for steel and vinyl gutters are also limited.
2. Seamless Gutters
Seamless gutters offer several advantages — they have a smoother appearance, come in more color options and experience very few leaks.
If you opt for seamless gutters, professionals will come to your home to do a "gutter run-out," which refers to roll-forming aluminum continuously through a specialized machine that extrudes the material and shapes it into gutters. This process is remarkably fast, as the machine can produce 45 feet of gutter per minute.
While professionals usually perform the actual installation, in some instances, the company will do a custom gutter run-out and then allow you to do the installation.
One of the most significant advantages of seamless gutters is that they will not experience any leakage at the mid-point — although leaking is still possible at corner joints over the top. They also come in a wide variety of colors and can easily match those of your home. Furthermore, as there is no limit to how long seamless gutters can be, they can accommodate roofs of any length.
As for the disadvantages, seamless gutters generally cannot be a DIY project, which means you'll have to pay for outside labor. Also, as mentioned above, if just one area fails, it affects the gutter's entire length, and therefore you will have to replace the whole thing or independently cut out and replace a section.
There are also several gutter profiles to choose from.
K-shape: The most common choice, the K-shape gutter profile somewhat resembles the crown molding you see in the interior of homes. They can carry a greater volume of water than gutters with a half-round profile, and the creases that run along the length of these gutters make them exceptionally strong.
Fascia shape: Gutters with the fascia style are narrow, tall and completely cover the fascia behind them. Due to the increased depth of fascia-style gutters, cleaning them is not easy.
Half-round shape: These U-shaped gutters are more traditional-looking than their K-shaped counterparts. If you choose copper for your gutter material, they will likely have a half-round profile. These gutters are particularly wide and can extend up to six inches from the fascia.
The most common gutter sizes found on homes in this country are either the six-inch half-round-style or the five-inch K-style. They are designed to handle rainfall on the majority of homes in most regions in the U.S. However, homes located in areas that experience strong downpours, as well as homes with steep roofs, may need gutters that are wider or have additional downspouts to prevent water overflow.
1. Calculate Square Footage
To determine the gutter size you need, the first thing you'll have to do is calculate the drainage area of your gutter system. For example, if you have a simple roof with gable ends, you'll only have to figure two areas, one for each slope. Intersection roofs and hip roofs, however, have many facets and will require you to add up the square footage of every surface in each drainage area to determine the total area.
2. Adjust for Pitch
A steeper roof will collect a copious amount of windblown rain. To measure the pitch of your roof, take a tape measure and two-foot level. Put one end of the level up against your roof, make sure it's level, then measure the distance from the roof to the level's underside at the midpoint, which gives a run of one foot. If there is a five-inch gap, for example, that means that your pitch is 5-in-12.
Once you've determined your pitch, you can then find out the roof-pitch factor by looking at the following table:
12-in-12 or above: 1.3
9-in-12 to 11-in-12: 1.2
6-in-12 to 8-in-12: 1.1
4-in-12 to 5-in-12: 1.05
Flat to 3-in-12: 1
3.Adjust for Rainfall
The United States Weather Bureau keeps records of the most amount of rainfall that can fall in five minutes in several places. The higher the amount, the larger your gutter must be to avoid overflowing during an intense rainstorm. Look at this table to find the figure for the rainfall intensity in your region.
4. Size the Gutters
To determine the adjusted area of your roof, multiply your drainage area by the rainfall intensity and your roof-pitch factor. Then, look at the following chart to figure out the size for your gutter. If your roof has multiple drainage areas and requires gutters of different sizes, choose the largest size.
5,520 square feet: five-inch gutters
7,960 square feet: six-inch gutters
2,500 square feet: five-inch gutters
3,840 square feet: six-inch gutters
Here is an example: The roof on a Pittsburgh home has an actual drainage area of 1,000 square feet and a 9-in-12 pitch, which means a pitch factor of 1.2. Multiplying 1,000 by 1.2 yields 1,200 square feet of effective area. Multiplying that by the maximum rainfall intensity in the area — 6.4 inches per hour — gives you an adjusted area of 7,680 square feet. Therefore, the roof needs six-inch K-style gutters.
If Your Runoff Is Excessive
If the runoff on your roof is too high to equip standard gutters, you can do one of three things.
Get wider gutters: Seven- and eight-inch gutters are available, although they will probably be pricier, and chances are good you'll need a professional installation company to custom-order them.
Increase the gutter pitch: Normally, the pitch of a gutter is about a quarter of an inch for every 10 feet. If you make the gutter pitch steeper, its handling capacity will increase, although it may appear askew.
Install additional downspouts: The recommendations above assume your system has correctly sized downspouts spaced 40 feet apart. Just as is the case with gutters, downspouts must also have a capacity that is the same or higher than the calculated runoff for the roof. Refer to the following chart to find out the number of additional downspouts you'll need. For example, if you add a rectangular 2" by 3" downspout, the capacity of your gutter will increase by 600 square feet of drainage area.
Three inches: 706 square feet
Four inches: 1,255 square feet
2" by 3": 600 square feet
3" by 4": 1,200 square feet
Gutter Types for Cedar Roofs
Gutters also come in a wide variety of materials. Find out what is the best gutter to go along with a cedar roof.
Vinyl gutters are widely popular due to their affordability, straightforward installation and resistance to corrosion and rust. They are exceptionally lightweight, and it's easy to snap the sections together, making it a very feasible DIY project.
The two main disadvantages of vinyl gutters are that they become brittle and crack in frigid climates and can sag if improperly installed. However, in regions with milder weather, properly installed vinyl gutters work just as effectively as most other materials, and they're an attractive option for homeowners with a smaller budget.
Aluminum is the next most affordable gutter material on our list. Aluminum gutters, like vinyl gutters, are also lightweight, impervious to rust and rather easy to install. However, they differ from vinyl in that they are resistant to all harsh elements, including freezing temperatures. They also hold paint well — which is not true of vinyl gutters — and are available in seamless options.
The only disadvantages are that they're not as sturdy and are susceptible to denting. You can partially mitigate this problem by buying gutters made from primary aluminum, a thicker, higher-quality material than secondary aluminum, which consists primarily of recycled materials.
Like aluminum gutters, steel gutters are also available in several varieties. The most popular option is galvanized steel gutters, as they are somewhat affordable and are more durable than aluminum gutters in terms of how susceptible they are to impacts from ladders and falling branches. The main disadvantage of galvanized steel gutters is that they can rust, although with regular maintenance, they can still have a long lifespan.
Stainless Steel and Copper
Stainless steel gutters are practically indestructible, will look good for many years, do not rust and are one of the most durable gutter materials out there. The main disadvantage is the high price. They can cost up to four times more than gutters made of other materials, so it may not be the best option for homeowners on a budget.
Copper gutters are also indestructible, and many people consider them to be the most attractive gutter material. As you might expect, it's also the most expensive.
A century ago, wood gutters were the norm. Now that more affordable, weather-resistant materials are available, its use has declined dramatically. While there are wood gutters available in fir, cedar and redwood, you'll primarily see them when homeowners renovate older homes and strive to stay historically accurate. Wood gutters are also one of the pricier options.
Zinc gutters are durable, resistant to rust and weather to a beautiful matte gray. Due to its rather high expansion and contraction rate when temperatures fall or drop, we recommend you get a professional installation. Zinc gutters require a complicated soldering process at the seams. They have a lifespan of 30 to 50 years, depending on how close the home is to saltwater. Owners of cedar roofs should be aware the acidic runoff it produces can harm zinc gutters.
Selecting the Right Gutters for a Cedar Roof
If you own a cedar roof, there are two problems you may run into when installing your gutters.
Rotting: In some cases, cedar roof installation involves the first row of cedar shingles extending down into the gutter. Since wood is porous, if the gutter fills up with debris and causes water to pool there, the edge of the cedar roof may be exposed. Cedar is not resistant to rot and is known to wick up moisture. To solve this problem, you should have a professional cut back the cedar shakes. Of course, it's best to prevent this problem from occurring in the first place by not having your roof extend into the gutter.
Inability to install gutter covers: Many homeowners like to install gutter guards to keep debris from accumulating and causing clogs. If the cedar roof is sitting down in the gutter, however, this installation will not be possible. Like above, we recommend you have a professional cut back your shingles. Doing it yourself may result in an unnatural look, which you don't want for cedar roofs.
Let Cedar Roof Coatings Care for Your Cedar Roof
If you're a cedar roof owner in need of a roof inspection, repair or maintenance, look no further than Cedar Roof Coatings. We are the leaders in cedar roof preservation, restoration and repair in Fairfield County, CT Westchester County, NY and surrounding areas and have earned a reputation for our professionalism and high-quality workmanship. To receive a free, no-obligation estimate on your cedar roof, contact us by filling out our online form.