Quick! Which gauge of metal roofing material is thicker? 29 gauge or 22 gauge?

If you chose 22 gauge, you picked the right number because in the world of metal measurement, the lower the number of the gauge, the thicker the material.

So, if your contractor tells you he’s going to order a 26 gauge standing seam metal roof for your house, he’s picked the most common roof thickness for a metal roofing system in America today. If he tells you he’s picked a 29 gauge material, ask why. Most metal roofing companies require a 24 gauge or better to ensure the roof will be suitably impact resistant.

That’s because impact resistance is one of the features that make it superior to other forms of roofing materials when weather and other aspects of Mother Nature come into play. How does its strength shape up against other roofing materials?

Well, measuring the flexural strength of asphalt shingles or even terra cotta tiles is a difficult task at best and a potentially pointless exercise since roof shingles do not provide weight support for a roof—just weather protection.  In fact, their manufacturers do not provide flexural strength information knowing this.

On the other hand, metal roofing materials have excellent tensile strength. For example, stainless steel roofs have been tested at 80,000 pounds of pressure per square inch. Galvanized steel comes in at 50,000 psi, copper at 36,000 psi and even lightweight aluminum rates 22,000 psi. Insurance companies know this and will often offer discounted premiums to homeowners with a metal roof. Nonetheless, heavier gauge does not necessarily mean better performance. Product design and manufacturing, quality of coatings and installation expertise can mean the difference as well. Continue reading →