Up on the Roof
Light-weight, coated aluminum, standing-seam roofing panels formed on site from coil stock are installed without need for a mechanical seamer
Standing-seam metal roofing has a reputation for longevity and durability in climates with a heavy snow load. But with modern coatings, metal roofing also has advantages for the hot, wet coastal climate of Rehoboth Beach. In this case, the roof panels supplied by Drexel Metals have an integral interlocking seam profile , and the proprietary “galvalume” substrate is coated with Fluropon, from Sherwin Williams Coil Coatings (formerly Valspar).
The lightweight aluminum coil stock resists rust and makes installation easier—most of this roofing was installed by one person—and the snap-together seaming system virtually eliminates the need for a panel seamer on the roof. The coating protects the metal from ultraviolet light, heat and humidity, and corrosive salt spray, while reducing chalking and fading (all of which extends the life of the roofing). And the Charcoal Gray color, one among many available, is a perfect match for the exterior color scheme.
Drexel Metals’ DMC 550S profile interlocks without the need for a panel seamer. The aluminum coil stock is coated with Fluropon from Sherwin Williams Coil Coatings (formerly Valspar).
The panels were formed on site from coil stock using a Drexel Metals fabricating machine . The bottom edge of each panel was modified by hand  to create a bend that would be crimped over the metal drip edge.
Roofing panels were stockpiled [2A] after being formed on site using a Drexel Metals fabricating machine [2B].
The bottom end of each panel is modified by hand. First step is to snip away the vertical legs on each side, leaving about a ¾-inch tab [3A]. The tab is then folded manually nearly 180 degrees using a simple bending tool [3B]. The open hem [3C] is clamped over the metal drip edge to create a clean termination at the eaves.
On the roof, work begins at the rake, with a starter panel and cap on each side of the ridge [4A]. Then successive panels are added one roof plane at a time by interlocking the seams, which requires only light hand pressure. Panels are held in place with a screw at the top and by metal hold-downs [4B] spaced at regular intervals along the free panel edge and screwed to the deck [4C].
The relatively short, light-weight aluminum roofing panels allowed most of the roofing to be installed by one person. Beginning with starter strips at the rake [4A], panels are added by locking together one seam and tacking the panel in place with a screw at the top, then using hold-down clips [4B] to anchor the free edge to the deck [4C].
When it was time to switch to the other side of the ridge, one person easily carried 2-plus-squares up the ladder [5A] and stockpiled them close to the work area [5B]. At valleys, field panels lock into valley flashing (W-shaped to allow for expansion and contraction) [6A]. Cap panels at the ridge provide the finishing touch [6B].
Field panels lock into valley flashing, which is W-shaped to allow for expansion and contracting without deforming. The last step is to fasten cap panels at the ridge [6B].