Metal Roofing Seamers in Construction Today

From the early days of developing and perfecting the metal roof through today, the seaming process endures as the real art of the install. In the early days, metal roofing was installed with hand-forming tools, crimpers, pliers and folders. As the product line improved throughout the years, the art of joining the individual panels evolved as well. The fine art and skill required to create an attractive and functional seam has been refined and divided into two distinct categories: mechanically seamed roofing and snap-lock seamed roofing.

Seaming equipment can be one of your most valuable tools

By Joe Tripod

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Snap-lock seaming has emerged as the foolproof method for joining metal panels without the use of complicated tools or metal working skills. However, most snap-lock panel systems are primarily used at or above a 3:12 pitch. Snap-lock panels are typically thought of as water-shedding systems, requiring underlayment to maintain its weathertight integrity.

Mechanically seamed systems have come a long way since the old days of the “tin knocker” hand-folding seams using specialized tools and a craftsman’s eye for perfection. Today’s seamers, both electrically driven and their associated hand tools (to start and finish metal seams) have advanced along with the metals and finishes we use now. Mechanical seaming incorporates the use of electrically driven seamers containing chrome-plated steel forming rollers to shape the panels’ overlapping folds into a smooth, consistent, weathertight joint. This ties the entire roof system together into one huge metal canopy that can cover a myriad of building shapes and sizes.

Neoprene drive rollers intermingled within the seamer’s forming sections drive the unit forward during seaming without scratching the panel’s painted surface. Mechanically seamed systems are used at much lower slopes and due to their method of seaming are considered waterproof systems, which can be used over open framing.

This equipment, although considered paramount in terms of speed, consistency, time efficiency and effort, can lead to disaster in the hands of unskilled, untrained workers if left unchecked. Some prime areas of concern when operating electric seamers on a project are:

• Be sure the seamer is a match to the roof system you are installing as all 1 1/2-inch mechanically seamed panels are not the same. The seamer needs to be matched to the profile.

• Always install the metal roofing tightly and consistent with the manufacturer’s recommendations. Panels not tightly joined during install will cause the seamer to ride up off the seam and ruin the panel folds.

• Be sure the operator has been trained to use the seamer and is familiar with its safe operation, what an acceptable seam looks like, and when to stop if it’s not.

• Hand seam the length of the electric seamer before you lock it on to match its forming roller layout. This ensures it will start properly and maintain the fold.

• Keep the unit clean and properly lubricated to avoid leaving marks on the roof panels and keep the inner gear system running smoothly.

• Run a few feet of seam and inspect for proper folding. Then carefully watch its operation to maintain consistency and avoid damage to the roof seams.

• Inspect neoprene rollers periodically for wear or damage.

While hand seaming tools are still an important part of any metal roofing job, the bulk of the work should be left to electric seamers for speed and consistency. Hand tools are needed to start and end each seam, and for use in tight spaces that the electric unit won’t fit.

Electric seamers are typically driven by commercial drill motors and, though strong and durable, require a proper power supply to prevent permanent internal damage. These units usually require a solid 110 VAC power supply tied directly to a site power pole. The power cord should be a minimum 10 gauge and extend not more than 100 feet from the pole. Alternately, you can power one of these units by a minimum 5000-kW generator, with the same power cord requirements as above.

Trying to run these types of units on smaller sources or with extension cords will eventually ruin the drill motor windings and brushes due to the power drop. Today’s electric seamers can cost several thousand dollars depending on size and manufacturer and need to be cared for as a precision piece of equipment.

Some manufacturers offer these units with an electric eye attachment that shuts the unit off at the end of the seam, preventing it from driving off the roof if it was to get away from you. Just another improvement to make the seaming process easier and more consistent.

Joe Tripod is chief operating officer at Englert Inc. in Perth Amboy, N.J. To learn more, visit www. or call 1-800-ENGLERT.

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