The Roofing Resource Blog

Standing Seam Metal Roofing Quick Facts

Thu, Jun 25, 2015 @ 09:50 AM | Perry

Learn more about standing seam metal roofing by browsing the quick facts.

1. Standing seam metal roofs are characterized by the seam between the metal panels being elevated or standing. This category of metal roofing is also known for having very few if any exposed screws or fasteners.


2. Metal roofing varies by the thickness of the steel measured in gauge. Common gauges of metal roofing are 29, 26, 24 and even a 22 gauge. The lower the number of the gauge the thicker the metal roofing is.

3. The biggest downside to metal roofing is oxidation or rust so before the steel is turned into metal roofing panels, it is coated with a mixture of zinc and aluminum. This protective coating over both sides of the steel coil is called galvalume.

metal_roof_rust4. Metal roofing coated with galvalume will prevent rust 3 to 4 times as longer than regular galvanized metal roofing.

5. Metal roofs have been around for thousands of years. There are standing seam roofs in Europe made of zinc and copper that are hundreds of years old and still working just fine.

6. Structural metal roofing refers to metal panels that can be installed over open framing. Non-structural metal roofing panels can only be installed over a solid substrate such as plywood or metal decking.

metal_roof_architectural_detail7. Architectural detail refers to hemming or bending metal panels so that they hook to or interlock to other pieces of roofing without using exposed screws.

8. Metal roofing panels are in constant movement from temperature changes. Metal roofing contractors must take into consideration the expansion-contraction cycle of metal when designing details and during the installation process.

9. Metal roofing expands or elongates about an 1" per every 100'. Aluminum standing seam expands or elongates at a rate of about 2" per every 100'.

10. Metal roofing is painted with many different paint bases, some lasting much longer than others. There is acrylic based, urethane based, silicone based and resin based.

metal_roof_paint11. Kynar Hylar and mylar paint is all resin based and is a longer lasting metal roofing paint. It resists weathering and fading, sheds dirt and is mildew resistant.

12. Standing seam metal roofs take skill, attention to detail, and training to install correctly. Many of the most common mistakes in metal roofing requires that large sections of roofing be removed to correct.

metal_roof_panel_install13. Metal roofing should never be cut using a saw blade or grinder. These tools open up the steel and the heat generated push the galvalume coating away from the cut edge leading to rust. Using snips or shears to cut metal panel pinches the galvalume coating away from the cut edge and protecting it from rust.

14. Warranties in the metal roofing industry are called weather tightness warranties and are usually issued for 20 yr period and covers leaks in the roof. This warranty is different than a paint warranty which only covers fading or flaking paint.

15. Standing seam metal roofs come in a variety of profiles. The profile is the shape or design of the panel.

metal_roof_house_716. The type of profile or design will determine which application the metal panel is best suited for. Some profiles can be installed as low as 1/4" fall in 12" while other metal roofing profiles can only be installed in applications that are 3:12 or above.

17. There are two main types of standing seam: mechanically seamed or snap lock. Mechanically seamed metal roofing panels must be bent over together to form the seam. Snap lock metal roofing panels are designed to push together and lock into place.

standing_seam_clip_18. Standing seam metal roofs are held down and in place with clips. These clips are hooked over the leg of the panel then the clip is screwed down. The next roofing panel cover over the clip and the screws. This is how standing seam metal roofs have very few exposed screws.

19. Modulation is the term used in the metal roofing industry that refers to keeping the metal panel on the correct layout. Standing in the pan of the metal panel while installing the clips to the purling's can throw a roof out of modulation.


20. Standing seam roofs can be made out of steel, copper, and aluminum. The most common is steel.

21. The metal roofing panels start off as large coils of steel. The coils are painted then roll formed into a profile.