Ahhh... Symmetry
By Amy Stokes

Symmetry is a beautiful thing! Why, the word itself just sounds like something good doesn't it? Say it slowly... S-Y-M-M-E-T-R-Y.

But you know what sounds even better? It's a phrase that describes what can come from symmetry: L-O-W-E-R - C-O-S-T. Now that is a beautiful thing!

"But what," you ask, "does symmetry have to do with metal roofing?" When it comes to metal roofing, symmetrical metal roofing panels definitely mean something good to installers, architects and building owners alike - a lower TCO! Simply put, symmetrical panels lower the overall cost of installing, maintaining and repairing a standing seam roof.

Symmetrical metal roofing panels:

Have vertical legs that are equal in both size and profile
Are typically joined by a separate seam cap
Can be installed in either direction (there is no need to match one side of one panel with the corresponding side of another panel

Non-symmetrical panels:

Have interlocking male/female seams
Do not require a separate seam cap
Can only be installed in one direction, from one end of the roof to the other, by matching male to female seams

Easing Labor Pains

Symmetrical panels offer installation flexibility, resulting in significant labor savings over interlocking systems. With non-symmetrical panels, installers must start on one end and continue laying panels in a single direction, one after the other. With symmetrical panels, however, crews can start from a center point on the roof and work in either, or both, directions. This capability alone can significantly reduce labor requirements, or allow contractors to add another simultaneous crew to expedite job completion.

Now imagine that there is a roof protrusion (such as a dormer, skylight, etc.) in the installation path that requires detail work from a craftsman. A symmetrical system allows the contractor simply move the crew and continue working elsewhere, assured that any panels inserted later will align properly.

With non-symmetrical panels, however, installation would be halted until the craftsman completed his work. Only then can the crew (which has waiting below and still "on-the-clock") continue laying the sequential panels.

Some would argue that symmetrical panels actually require additional labor to install the separate seam cap. While the cap does present an additional component, both in material and labor, the time and cost required to install caps is negligible. By the time you add up the crew's "stand-by" wages, the daily equipment mobilization costs, and potential liquidated damages as the deadline approaches, the time- and labor cost-savings of a symmetrical system can be significant.

Living in a Material World

While you shake your hips to Madonna's tune that's now playing in your head (c'mon - you know you are!), think about hips and valleys.

When cutting a symmetrical panel for installation at hips and valleys, there is very little waste. This is due to the fact that, when the panel is cut, each piece can be used for opposite sides of the condition. With a non-symmetrical panel, the remainder of the cut panel is waste - and waste equals cost.

Murphy's Law

Metal roofing specifiers are trending toward requiring that "individual panels shall be removable for replacement without removing adjacent panels."

Imagine a new metal roof on a public building that is still under construction. Now imagine a roque forklift driver getting a little too close to three or four panels in the middle of the building. Or, a stucco contractor getting a little "spray happy," and speckling your new roof with stucco overspray. So, the decision is made to replace the damaged panels.

At this point, the architect who specified symmetrical seam is breathing a sigh of relief, because with symmetrical panels, only the damaged panels need to be replaced: The damaged panels' seam caps are removed, the panels are pulled off and the replacement panels fit snugly into place.

The architect who specified a non-symmetrical panel, however, is watching what should be minor repairs turn into a not-so-minor local news story about wasted taxpayer dollars.

Faster installation at a lower cost; reduced waste; easy, economical repair and maintenance - with all of these benefits and more, symmetrical panel systems are definitely a "beautiful thing." Ahhh ... symmetry!