There are many advantages to running a single-lock standing seam profile through your roll-forming machine. The single-lock profile is clean looking because the ribs are tight. It is efficient, consuming only 3 inches of material for 1-inch-tall ribs (and 4 inches for 11⁄2-inch-tall ribs). But the most desirable feature of the single-lock pan profile is its versatility when customizing details. Nowhere is this more evident than in valley construction.
PreparationInstall roof underlayment, drip edge and primary ridge details before installing the valley pans. When the tops of valleys terminate into a larger roof plane, as in the case of lower gable dormers and ells, install the ridge cap on the dormer after the valley pans are installed. If the bottom of the valley terminates on a roof plane that extends below, the roofing panel below the valley is installed before the valley pan. This roof pan will terminate at the front of the valley; the valley pan will be cleated to it, and the top half of the roofing pan will be applied after the valley is installed.
Fabricating and Installing ValleysStep 1: Measure the valley from the highest point of the valley pan termination at the peak to the longest point where the valley pan will bend around the drip edge or lower pan cleat. Make a roof panel this long, leaving enough metal to make the hems. (See photo 1.)
Step 2: When the pan is made, hem the female downward facing leg flat against the top of the rib using hand tongs.
Step 4: Bend the legs inward so that they form a slightly open hem on either side of the valley pan.
Step 7: Affix the valley pan to the roof deck using standard roofing clips straightened with hand tongs so that they hook into the hem and can be nailed or screwed to the substrate. (See photos 6 and 7.)
The final step is to install a "bowtie" cleat that joins the two hems of the opposing valley just over the top of the ridge cap. This cleat is applied over a 1-inch butyl tape or polymer sealant. (See photo 9.)
Use and Fabrication of Double Male PanelsA double male panel is used when applying roofing panels in both directions across a roof plane. On a large run, you may want to run two installation crews for one fabricator. A good fabricator can usually keep up with two crews, especially if he has a runner to bring panels to the installers and to help with the application of backer rod (if used). A more common use for the double male panel is to orient roofing applications between two valleys so that both valleys are applied from the bottom upwards and terminated at the top.
Measure 3⁄8 of an inch across the top of the newly formed male rib, snap a line, and cut off the excess steel with a power shear so that you have identical male ribs facing each other on either side of the roof pan. (See photo 13.)
Installing Roof Pans in a ValleyStep 1: When installing roofing panels in a valley, work from the bottom upward with the male rib in. The installer calls long point measurements for the female rib and tells the fabricator roughly how much to drop from this measurement for the male leg side.
The fabricator makes the pan to length and fabricates a box pan on the ridge end. He scribes the cuts on the drop, leaving enough metal to make a full hem but removing enough so that the pan will lie flat in the valley. (See photo 14.)
Pound each panel hem down flat to the valley with a rubber mallet. Don't be afraid to hit the metal hard to get a very flat and sealed hem. (See photo 17.)
Making a Double Female Roof PanWhen roof panels are run up both sides of the opposing valleys, there will be two roof pans with male ribs facing opposite directions. These two pans will need to be joined together with a double female ribbed pan. (See photo 18.)
Step 1: Make a pan long enough to run from the peak to the longest of the male ribs with a little extra for the hem.
The use of double male and female panels is an advanced concept and requires some craftsmanship, but once the crew has become familiar with these details they will not want to return to old methods. The time incurred making these specialty pieces is quickly recovered in the following panels and the quality of the installation is hard to duplicate.