Go-to guide on zinc
Standard cutting, routing and folding tools will work with RHEINZINK as long as proper working temperatures and bending radii are followed . Please reference “Cold Weather Bending”, below.
Cold Weather Bending
Zinc becomes brittle at material temperatures below 50° F (10° C). The lower the temperature gets the more the risk of fracture while folding. At material temperatures below this threshold, preheat the area to be folded with a hot air gun or heat lamps. Do not attempt to bend or fold RHEINZINK in ambient temperatures below 14°F (-10°C ).
Minimum Bending Radius
To avoid fracturing RHEINZINK during fabrication, minimum-bending radii must be used in all temperatures as illustrated in Fig. A.
RHEINZINK "Do's and Don't's"
DO use proper details for all conditions.
Because of the importance of providing VENTILATION and allowing for THERMAL EXPANSION with RHEINZINK, it is important that installation details are properly designed for the maximum longevity of the system being installed. Occasionally, special details require special tools; contact RHEINZINK for information on where to obtain proper tools.
DO allow for expansion.
As with all materials, thermal expansion must be considered. A minimum of ¼” per 10’ or more should be calculated depending on the system, area and climate of the application. Since this is the case, proper detailing must be implemented with flashings as well as the use of fixed and sliding clips positioned properly to allow for expansion and contraction of the roof or wall systems. When installing flashings, individual pieces may be pinned (fastened) but not the joints (laps). If the joints (laps) are pinned (fastened) together allowances must be made for thermal expansion (movement) at the ends.
DO pin the pans.
Fixed clips are used to hold the panel in position as well as control the direction of thermal movement. The number of fixed clips depends on engineering, area of application, drag loads and installed accessories such as snow retention systems or solar panels. Once the panels have been positioned, either snip part way into one of the fixed clips or cut the male flange of the seam at an angle to the clip and bend the tab over the fixed clip. This will keep the pan from sliding out of its original position.
DO prepare the seam.
In order to close a roof pan seam into a double lock seam you must first finish the double lock by hand at the end of the panel for a minimum distance of half of the electric seamer length. Then position the electric seamer on the double lock such that the two rear seaming dies are on the double lock and the two
front dies are under the single lock (angle seam), then you can start closing the double lock . It is recommended to close the single lock (angle seam), every three to four feet by hand to keep the pan from lifting up when closing the seam with an electric seamer.
DO seam as you install.
RHEINZINK recommends seaming while installing. RHEINZINK has a clear PRO coating that is applied at the factory to help protect the pre-weathered finish from finger prints and scuff marks during fabrication and installation. This also acts as a lubricant when double locking the seams together. However once the material is exposed to rain and UV this clear PRO coating will begin to wash off and the natural patina will start to form making the material dry and more difficult to double lock together. If this happens before the seams are closed, use a low PH dish soap (sparingly) to lubricate the seams.
DON'T use a scratch awl.
When marking lines on RHEINZINK it is not recommended to use a scratch awl or butt scribe as this can score the zinc and when folding or bending the material it can fracture or crack on that scribe line. Use a pencil to mark all lines. The use of a felt tip marker could stain the zinc and become part of the patina.
DON'T tear the material.
If you are experiencing problems with the material tearing at notches, you must use a metal punch to create a small hole at the vertex of the notch. Punch a hole at the vertex of the notch then cut to the hole, this will stop the material from tearing. If you are peening the material over at eave details or similar conditions and are experiencing tearing you need to be sure that there are no burrs on the cut edge. Burrs must be filed smooth to stop the tearing. Burrs are like v-notching they are not a finished edge and can allow the material to tear when bending or peening.