Why zinc/tin alloy coated steel is ideal for gutters and accessories
By Mark Robinson, Follansbee Steel
For new construction, renovation or restoration projects, terne metal roofing and accessories are an ideal choice. Metal is a sustainable, long lasting and cost efficient roofing solution that lends dramatic appeal and enhanced durability to residential, commercial and institutional applications.
The roof is an essential part of the building envelope and the roof drainage system is just as important as the roof itself. Gutters and rain goods collect rainwater and direct it away from the building, prolonging the life of the roof and the entire structure. However, sometimes gutters and other roof accessories are typically thought of as secondary elements and are not given the attention they deserve.
Choosing roof accessories
When it comes to choosing roofing accessories, terne-coated steel outshines wood, aluminum and copper gutters. Wood gutters are rare and can give structures a rustic look, but they are short-lived and require maintenance to prevent the wood from drying out.
Wood is heavier and cannot match steel’s durability, especially in harsh coastal areas.
Compared to steel, aluminum gutters expand and contract more. Terne gutters are stronger than aluminum and are coated with a zinc/tin alloy that provides unmatched durability. Copper is a high-quality material, but naturally oxidizes and turns green unless treated with a sealant. Copper also is susceptible to drip-line corrosion and if the material cannot dry, it will erode and fail quickly.
When choosing steel roofing and related goods, be sure to look for a manufacturer that can provide you with a full range of accessories designed to work in conjunction with your roof for long-term durability, including gutters, downspouts, snow guards, panel profiles, valleys, ridge caps, miters, drops, conductors and elbows.
To ensure aesthetic, mechanical and performance continuity between a Follansbee Steel roof and its drainage system, Follansbee offers a complete line of the highest quality rain goods, roofing accessories and snow guards made from either TCS II or TCS II Satin materials. All Follansbee Steel products are coated with Follansbee’s patented ZT (zinc/tin) alloy for enhanced corrosion resistance.
If the roof manufacturer does not offer gutters or other rain goods, careful consideration should be given to the selected materials. The roof manufacturer may be able to provide material selection guidelines for accessories.
There are factors to consider in terms of roof drainage design and installation include hanger spacing, gutter position and sizing.
When choosing gutter hangers, aesthetics, expected life, ice load, gutter size and material expansion need to be evaluated. Gutter expansion should be accounted for, as gutters will expand and contract slightly in response to temperature changes. In areas with heavy snow and ice, gutter hangers should be spaced closer together.
Gutter position is determined by the pitch of the gutter and the slope of the roof. A typical gutter slope is typically one-to-two inches for 40 feet of run. A gutter with too much slope will overflow and can cause damage to a building’s foundation. A gutter with not enough slope will hold a lot of run-off water and will need additional support to hold the weight of water. Gutters need to be placed below the roof line to allow snow and ice to slide clear.
The size of the gutter, downspouts and drains depend on the roof size, type of building, aesthetics and rainfall intensity. When determining the size of a gutter, spacing and outlet openings, roof slope, maximum gutter length and capacity need to be considered. The capacity of the gutter and downspouts should be consistent, as a gutter should not hold more water than the system selected to drain it.
In areas with heavy snow, snow guards should be installed to prevent gutter tear-off. There are many considerations to keep in mind including fastener or solder strength, roof pitch, snow loads, rafter length and the amount of roofing area. Another critical element is material compatibility. Follansbee Steel, for example, offers Sno-Gem snow guards in TCS II metal, one of the company’s roofing materials.
Partnering with Sno-Gem allows Follansbee to provide customers with top quality snow guards manufactured from Follansbee’s own architectural stainless steel product plated with their patented ZT alloy. Sno-Gem is recognized as a leader in the snow guard industry. Combining that expertise with Follansbee’s steel alloy technology creates an exceptional product and a valuable addition to the product line.
Gutters and rain goods are just as important to the performance of your roof as the primary roofing materials chosen and the level of craftsmanship of the roof installation itself.
The biggest and most common problems regarding gutters and other rooftop accessories comes from the failure to follow their proper installation methods. When gutters are not installed properly, their performance is compromised, voiding any warranties and leaving roofing contractors and building owners dissatisfied with the product. The best approach is for gutters and other rooftop accessories to be installed by professionals who have received proper training.
The manufacturer knows the product best and the installation techniques that will provide peak performance. Many manufacturers offer classes, online step-by-step training videos and other training materials to ensure their products are installed correctly and provide guidelines for proper installation. It is also suggested that questions about installation are directed to the manufacturer’s technical team prior to or during the process.
Knowing how to install gutters and other accessories is not the contractor’s only concern. Where to install the product is also critical. Proper placement allows the product to function as it was intended. For example, if gutter downspouts are spaced at incorrect intervals, they can clog the gutters and cause damage to the building.
Several manufacturers, including Follansbee Steel, refer to standards set by the Sheet Metal and Air Conditioning Contractors’ National Association. It is an excellent resource for roof drainage system design for gutters and downspouts with guidelines on gutter and downspout size requirements, construction techniques and alternative methods of design and installation reflecting climatic conditions and rainfall rates.
The local building code is an important final consideration before installing accessories or any building product. Many contractors service a wide geographic area and it is important to be familiar with local building codes prior to product installation.
Most importantly, be sure to choose a responsible metal roofing manufacturer who can work with you throughout the design-build process, providing the necessary recommendations and assistance to meet all of your building design, engineering and construction needs.
Mark Robinson is president & general manager for Follansbee, the only manufacturer of a pre-painted or natural terne roof and the leading supplier of metal roofs for new and retrofit commercial, residential and historic projects. He can be contacted at 304-527-1260 or firstname.lastname@example.org. Visit www.follansbeersteel.com for more information