Taking America by stormwater:
European zinc roof drainage system offers aesthetics and effectiveness
Steve Shull, CSI, CDT, LEED AP,
Posted
07/01/2009
The basic
function of a roof drainage system is to collect stormwater runoff
and channel it away from the building. The market now offers many
gutter, downspout and accessory options that can provide this
primary drainage function. In today's world market, there are many
product options that offer a number of styles, profiles, materials,
aesthetics and attachment methods over a wide range of price and
performance levels. Over the years, the European producers have
redesigned copper and zinc roof drainage as a complete "system"
unlike other domestic (k-style, box or half-round) designs. Zinc
gutter systems, which are an everyday commodity in many European
markets, are now readily available from many North American
distributors-and the price may surprise a few when compared to
copper, stainless steel and some coated-metal alternatives.
The Benefits
Natural gray aesthetics, low ecological footprint and good
durability are all attributes of zinc. However, it's the system
design and ease of installation that helps close the deal for many
first-time installers. Offering a good combination of
functionality, beauty and classic German engineering, the RZ gutter
system is produced using a heavier gauge material-0.03-inch
(0.7-mm) -compared to the 16-ounce copper material-0.02-inch
(0.549-mm)-most domestic fabricators use. The combination of high
performance and full system design is what makes the European
gutter system special.
Half-Round Shape
Thanks to the geometry of the half-round gutter, the dependence on
slope to move water is greatly reduced compared to flat-bottom
gutter designs. Even a minimal pitch toward the outlet is effective
for moving water while also providing a more desirable aesthetic,
as level gutters tend to look better from the street than gutters
with slope. Watertight gutter connections typically are made by
soft soldering though a zinc gutter adhesive soon will be
available. Thanks to tight fabrication tolerances, the gutter
sections nest tightly so a proper solder joint can be achieved. The
half-round shape is also the most efficient use of material for a
given volume.
Support From
Below
Another fundamental difference between European gutter design and
the American way is the method of gutter support or attachment.
European gutters are supported from below with brackets rather than
hung from above. Cradling a gutter from below is structurally
preferred rather than hanging a gutter from the outside metal edge.
Gutter brackets also help provide a clear and uninterrupted
waterway for cleaning and maintenance. European brackets are not
mechanically attached to the gutter, allowing the system to expand
and contract as temperatures change, reducing many thermal
stresses.
Accessories: Funnels and More
The weak link in most gutter installations is the connection
between the gutter and the downspout. Traditional drop-in outlets
create two problems: First, the hole must be smaller than the
downspout. Second, the outlet installation creates a dam at the low
point where water is directed to flow down, resulting in ponding
water. The European solution to this problem is a larger hole in
the gutter that sheds water to the smaller downspout opening. The
simple solution that satisfies this transition problem is a funnel
or gutter plug-in. Essentially, it is a friction-fit collection box
that is easier to install. The result is 30 percent increased
drainage flow for about the same installed cost.
Other engineered accessories include prefabricated seamless gutter
corners, snap-on end caps, downspout adapters and two downspout
hanger options. Finally, if you are interested in harvesting
rainwater, the European system has a spliced-in rainwater diverter
that collects water in your rain barrel.
Adding Sales With Better Value
The system is the key to European gutters. Improved water flow,
ease of installation, stronger bracket alternatives and designer
aesthetics make European zinc gutter systems a high-performance
gutter value. As more contractors and architects become aware of
this European option, they will understand how easy installation
and happy customers translates into more sales.
Steve Shull, CSI, CDT, LEED AP, is the regional sales manager at
RHEINZINK America Inc., Woburn, Mass. For more information, go to
www.rheinzink.com.
www.rheinzink.com