Make an educated decision when buying metal panels.

Buying metal roofing and siding can be confusing. Panels from different manufacturers may look similar, but can vary widely in quality and performance.

Don’t get fooled into thinking you are buying a quality metal roof just because your quote says 26 gauge with a 40-year warranty. Terms such as gauge and warranty are loosely used and can be deceptive. For example, a 29 gauge metal panel can vary in thickness and hardness between manufacturers. It doesn’t do you any good to choose a cheaper quote and end up with a thinner metal roof.

It is important to know what you are being sold so you can make an educated purchase. Become educated in the following three areas:

Ask your metal supplier what levels of protection are offered in the quote they are giving you. Remember, don’t make a decision based solely on gauge and warranty.


Focus on dent protection, not gauge.

29 gauge metal roofing comes in a wide range of thickness and hardness levels. That’s not a typo. You really can buy a thinner/softer 29 gauge metal roof or a thicker/harder 29 gauge metal roof. There’s not a huge difference in price for the better product, but you’ll definitely see a big difference in performance against hail and other dents.

By understanding dent protection, you can dramatically improve your roof without much impact to your wallet.

Simply asking for a specific gauge is not enough.


FACT: Metal roofing is offered in 2 varieties of hardness: grade 80 and grade 50.

Grade 80 is harder, and it is meant for panels that need the ultimate protection against dents.  Grade 50 is designed for trim, since the softness of the metal allows for sharp bends without the cracking that can be caused by over bending grade 80.

Some manufacturers do not want to carry two levels of inventory, one for panels and one for trim, so they only carry one or the other.  This results in manufacturers either making panels out of soft metal, or making trim out of hard metal.  Either way, you get a product that doesn’t perform well.


FACT: There can be a 40% difference in dent protection between 29 gauges.

In the metal industry, gauge is a range of thicknesses that manufacturers have to stay within.  With profitability causing pressure on costs, a lot of manufacturers are offering the thinnest metal that is allowed within the gauge. So, it’s important that you understand the thickness of your metal so you can make an informed decision.

There is a 40% difference in dent protection between the low and high end of 29 gauge. This difference in dent protection is an important consideration when investing in a metal roof.

Dent Protection ∝ hardness2 x thickness4


Focus on fade protection, not warranty.

A warranty can give you peace of mind when investing in a new metal roof. Don’t be misled by manufacturers offering a lifetime warranty. No one wants a metal roof that is faded, no matter how long the roof lasts. More than the term of the warranty, you should be concerned with fade protection.

Fade protection is a result of the type of paint used and how thick the paint is applied. A manufacturers warranty should list the acceptable amount of fade the warranty allows.

Move the slider to see how a 40-year warranty can fade differently based on paint type and thickness.

Paint Type

FACT: The paint system you choose affects fade performance.

There are three major types of paint used in the metal roofing market: polyester, SMP and Fluropon®. All three can come with the same warranty, but may actually offer more or less fade protection.

Polyester is the most basic paint system, giving you the least amount of protection against fading. The most common paint system, SMP (siliconized modified polyester), offers excellent protection against UV rays to improve fade performance. Fluropon uses a more expensive technology that helps the paint adhere better and lessens fade. Due to cost, Fluropon® is reserved for projects that demand the ultimate in fade protection.

Paint Thickness

FACT: Some metal panels have a thin coat of paint.

Remember painting the baby’s room and discovering you should have rolled the paint on thicker? A thicker coat of paint fades less, but of course costs more since it uses more paint. The marketplace offers 40-year warrantied metal panels at a wide range of costs. To make sure you are getting a quality product, ask your manufacturer for the paint thickness on the panels you are considering buying.

You may find that the metal you were quoted features a thinner, cheaper coat of paint. A full thick coat of paint should be between .9 and 1.0 millimeters thick, including primer.

Fade Protection ∝ paint type & thickness


Don't worry about rust.

Your metal roof will be exposed to rain, humidity and harsh weather conditions. Metal manufacturers use different types of rust-blocking coatings to protect against rust corrosion.  These coatings are applied between the steel substrate and the layer of paint. If the paint gets scratched, the rust-blocking coating is exposed and will prevent rust from reaching the steel substrate. There are two common forms of rust-blocking coatings, galvanized and Galvalume®.

Manufacturers also may include a separate substrate warranty depending on the rust-blocking coating you choose. As you learned above, a 40-year warranty refers to paint only. Ask your supplier if your quote includes a separate warranty for the substrate.

Galvanized Coating

FACT: Shows little to no edge-rust for the first 10 years.

Galvanized has long been the industry standard coating for rust prevention. This coating uses rust-inhibiting zinc, which protects the steel core from corrosion at the panels edges and any surface cracks or scratches. The thicker the layer of zinc, the longer you have before it corrodes away and exposes the steel substrate. Galvanized is offered in three levels of protection: G40, G60 and G90. A G40 coating has .40 ounces of zinc per square foot of panel.

Choose the highest amount of zinc for the most protection when choosing a galvanized panel.

Galvalume Coating

FACT: Can offer up to 4x more protection.

Some manufacturers offer a rust-blocking coating called Galvalume®, which mixes aluminum and zinc. Aluminum is highly resistant to corrosion. The aluminum will stop any rust that may occur in the zinc, and the steel will remain intact. After this small amount of edge-rust, Galvalume offers up to 4 times the protection of comparable options. Galvalume® is also offered in three common levels of protection: AZ35, AZ50 and AZ55. The higher the number, the thicker the layer of aluminum/zinc that will protect your metal.

When choosing Galvalume®, choose the highest amount of aluminum/zinc for the best protection.

Rust Protection ∝ coating type & thickness

Lower your energy bills with a metal roof!