Restoration Guide: Roof Gutters
Editor's Note: This is article 13 of 13 in the Roofs Chapter of the Old House Web Restoration Guide. This guide was developed and edited for old homes from original materials in the U.S. Housing and Urban Development (HUD) Rehab Guide.
13. GUTTER AND LEADER SYSTEMS
Section 1--The Basics
Sure, taking care of your gutters can be a drain, but they're the crucial last link in your water-protection system, and they need regular attention to perform properly.
Gutters and leaders (or downspouts) take the precipitation that hits your roof and funnel it away from your building. Malfunctioning gutters and drains can lead to water and ice backing up against the fascia and under roofing, perhaps causing structural damage. Faulty systems also can lead to erosion and water intrusion in basements and crawl spaces. And unfortunately, gutters systems are subject to wide-ranging abuse, including extreme weather, falling debris, and ladders.
Gutter engineering is simple. They are sized according to the area of the roof they must drain, and they should slope at least an inch for every 40 feet. The standard roof gutter is a 5" K-style design--a 6" K-style would be used for large roofs. Half-round gutters are usually sized an inch larger to provide the same overall capacity as a K-style.
Leaders drain the gutters and direct the water away from the house. The largest maintenance concern is at connections between gutters and downspouts and the downspout and drain pipes, where leaves and other debris can clog the system.
Old houses, before the 1960s, typically had wood gutters, and sometimes metal gutters in the half-round shape. Roll-formed metal gutters, first galvanized, and now usually aluminum came into use in the 1960s. That technology allowed metal gutters to be made lighter and more cheaply. The dominant gutter shape now is the K-style, though half-round and box styles can be found. Truck-mounted fabricators allow the production of continuous, seamless custom gutters to be made onsite.
Vinyl (PVC) gutters also are available, usually in the do-it-yourself market because of their ease of installation.
Section 2--Gutter Materials
Besides keeping gutters free of debris, gutter maintenance usually includes replacing broken hangers or tightening connections. Old houses may have deteriorating wood or steel gutters, though it is possible that they have already been replaced in a previous home renovation. If your system is showing extensive deterioration, it is time for a replacement. Here are some common types of gutters.
2.1: New Wood Gutters
Why, you might ask, would a person install wood gutters today? For looks. If you own an old house, you might want to keep the same rustic appearance--they go particularly well with shingle siding, for instance. They can be painted to match the trim.
Wood gutters generally are milled from clear fir, though they also are available in cedar and redwood.
Downspouts for wood gutters can be copper, black iron or PVC; some traditionalists box the downspout in wood for appearance. Wood gutters can last 50 years or more with proper maintenance; however, that maintenance is very time-intensive. Skip the upkeep, and you'll have rot before you can say "aluminum."
Wood gutters may not be available everywhere, and they are more expensive than many other gutter systems.
2.2: New Steel Gutters
Steel gutters come in the three basic styles: K, half-round, and box. They are electroplated or hot-dipped galvanized, or Galvalume (a trademarked process plating with aluminum and zinc), and can come in a variety of finishes. Their downspouts also are steel to avoid galvanic action between dissimilar metals.
Steel gutters can be fabricated from a continuous roll onsite or bought in pieces and assembled (cheaper than continuous). Steel is stronger than aluminum, but some galvanized coating does not hold up well, especially in maritime climates. If not properly cleaned and primed, it does not hold paint well.
2.3: New Aluminum Gutters
The most popular of gutter systems, aluminum gutters come in the three basic shapes. They come in various thicknesses, with .027" the most common for residential housing. Upper-end houses may have .032" aluminum, and thinner (down to .019") is available for "price-sensitive" applications.
Nowadays, continuous, seamless gutters made onsite are the norm, though stick pieces are available for assembly.
Seamless aluminum gutters are relatively cheap and easy to maintain. They come in a variety of colors. One downside is how easily they are dented.
2.4: New Copper Gutters
Copper is a longtime gutter system for large houses (especially high-end). It is available in K-style and half-round, in either "stick" systems or soldered for seamless installations. They can be an effective design element in old-home renovations and in historic renovations. Because of the expense and skill needed in installation, copper systems usually are reserved for custom projects.
2.5: New Half-Round Copper and Aluminum
Half-round gutters were common before the 1950s, and still are available for home renovation projects, plus they are a popular design element in up-scale custom work. The clean lines of half-round complement the heavier appearance of shakes, slate, and tiles. Of the main gutter styles, half-round systems are least affected by ice and snow. They are a little pricier than their K-style copper and aluminum cousins.
2.6: New Vinyl (PVC) Gutters
Used mostly by do-it-yourselfers, vinyl gutters can be easily installed with just a few tools by the amateur. They are strong and resist dents, don't peel, rust or chip, and can be painted. They are effective in salty or acid-rain environments. Despite their advantages, some people see them as low-end products.
Section 3--Keeping Your Gutters Free of Debris
Manufacturers have designed a variety of products designed to keep debris out of your gutters. These fall into two general categories: screens and guards or helmets. Screens block the flow of debris, but allow water through. They rely on wind to blow the debris off the screen, though sometimes that must be accomplished manually.
The guards are rounded caps that rely on the water following the rounded edge and dropping into the gutter while the debris drops of the edge to the ground. These may let small pieces into the gutter. Some of these guards are integral parts of the gutter, which make it difficult to clean out the small bits that do make it into the gutter. Others are attached separately and can be removed to make cleaning easier.
Both types of systems allow some water to spill over the edge in heavy rain.
Jim Mallery, a semi-retired journalist and onetime registered contractor, has extensive experience remodeling, repairing, and rebuilding homes.