But poorly functioning gutters and downspouts are responsible for exterior damage as well, eroding soil, and causing moisture problems like peeling paint and rotted siding, fascias and soffits. In short, for most houses, gutters (called eaves troughs in some areas) are a necessary evil. But with a little knowledge and some basic maintenance and troubleshooting work, you can keep this water management system working well and avoid all the problems that occur when water gets where it doesn’t belong.
Gutter Materials and Shapes
Most modern gutters are made from aluminum, but other materials include copper, galvanized steel, and even plastic. Copper gutters have soldered seams and are usually professionally installed. They’re also the most expensive option. The most common gutter shape is called “K-style” (so called because that’s where the shape falls alphabetically in the list of gutter profiles in the Sheet Metal and Air Conditioning Mechanic’s National Association architectural sheet metal manual). K-style gutters are flat on the bottom and back, and have an ogee profile on the front, similar to crown molding. Most times, they’re 5 inches wide, but 6-inch widths for large roofs are also available. Professionally installed gutters are typically 5-inch, K-style ones made on-site by a truck-mounted extruding machine that turns flat aluminum coil stock into seamless gutters of any length. The only joints, where leaks commonly happen, are at corners. 5-inch, K-style gutter is also readily available at home centers in 10-foot lengths, along with the corners and end caps required to complete the job. The other common gutter shape is half-round, either 5- or 6-inch. While the half-round shape is more historically correct, it doesn’t have the volume that K-style gutters do. Other historical gutters ranged from two boards nailed together in a long V-shape at the bottom of the roof, to concealed gutters (sheet-metal lined troughs just above the edge of the roof), to long sections of redwood or Douglas fir milled into half-round gutters. Downspouts come in the same variety of materials as gutters. The aluminum downspouts typically used with aluminum gutters are rectangular in section. Downspouts used with other types of gutters are more likely to be round.
Installation Details for Durability and Effective Drainage
Gutters need to be pitched to drain effectively, with the high side farthest away from the downspout. Professional installers typically aim for a pitch of ¼ in. over 10 ft. of length. How gutters are attached depends on the type of gutter. Half-round gutters rest in brackets screwed to the fascia. K-style gutters can be spiked or screwed to the fascia; screwed connections are stronger. Another method calls for gutters to be held in place by straps fastened to the roof. This technique is usually only used when there’s no fascia board. A downspout is installed by fitting it over the drop outlet on the gutter, and screwing downspout supports to the wall of the house. Downspouts should be installed with a minimum of elbows, because elbows are where clogs are most likely to happen. It’s best if downspouts drain into a sub-surface pipe that leads downhill to daylight, or to some sort of a drywell that can dissipate the runoff. If you have to drain the downspout on the surface, be sure the leader drains at least 10 feet from the house to avoid water issues. One other option for handling roof runoff is to collect it in a cistern, so the water can be used for irrigation or other purposes.
Maintenance and Repairs
Gutters need regular cleaning. A ladder with a standoff that rests on the roof is the best way to avoid leaning the ladder on the gutters themselves and damaging them. Also, inspect the hangers for looseness. Spikes in particular loosen over time and it’s a good idea to replace them with gutter screws. All gutters (and especially aluminum gutters) can be dented and deformed by impact or excessive pressure. This can result from a branch that falls on a gutter during a storm, or from a ladder leaned against the gutter. Instead of attempting to repair this kind of damage, it’s usually best to replace the gutter. Joints in aluminum gutters can develop leaks over time. Typically sealed with caulk, these joints occur at corners, end caps, and drop outlet locations. Cleaning the joint area and resealing with caulk usually solves the problem. If your house has galvanized steel gutters, you’ll need to look out for rusty areas that indicate the protective galvanized coating has worn off. Rusty areas can be cleaned and protected with spray finish, but this treatment will probably need to be repeated to provide continued protection against corrosion. You can minimize the need to clean gutters by installing gutter guards. There are many types, from simple screens that fit inside the gutter to professionally installed proprietary systems. They’re an investment, but they can save a lot of time in the autumn. No matter what gutter material or style is used on a house, it’s important not to take this protective system for granted. Checking and fixing leaks and clogs on a regular basis ensures that your gutters and downspouts perform as they should. If you take care of them, they’ll take care of your house.
