Zinc and copper have been used widely in construction over the last 200 years, offering better longevity than traditional metals, which rely on paint and other coatings to protect them. There are beautiful examples all over the world of these traditional high-end metals. Today however, there are better alternatives for those who wish to create long-lasting buildings and address modern concerns about the environment – specifically global warming, energy conservation and environmental contamination. InvariMatte® stainless steel and InvariSand™ titanium address these concerns beautifully. While these newer, high-tech materials are well-suited to a modern-contemporary design aesthetic, they also look at home on historic restorations. For quick facts, go to: Can Your Roof Go the Distance?
Superior Solar Reflection: Stainless steel provides a natural radiant barrier, which is particularly important for roofing, but also provides energy benefits when used as wall cladding. Stainless steel naturally reflects more than 90% of the sun’s radiation without generating heat. This provides a significant offset to global warming and heat island effect in urban areas. Additionally, since most of the sun’s energy is reflected, heating and air-conditioning burdens are lessened on the building's interior, thereby reducing operating costs. Much has been written in recent years about the benefits of white painted roofs providing efficient solar reflection, but the downside to this type of system is that painted roofs lose 5% or more of their solar reflectance each year due to oxidation. Zinc and copper both oxidize as well, which result in a significant loss of solar reflection over a short period of time. InvariMatte® stainless steel does not lose solar reflection performance over time. For more information regarding this topic click here.
Titanium is also a very good solar reflector, but is about 20% less efficient than stainless steel. However, it is still substantially more efficient than zinc or copper, which are essentially black bodies once their patinas develop.
Self-Cleaning Finishes: InvariMatte® and InvariSand™ have micro-embossed textures which provide hydrophobic surfaces that resist the accumulation of dirt. This allows easier cleaning and the accumulation of less dirt on the building surfaces in the first place. More than just a cosmetic advantage, this tendency to resist dirt provides the means by which solar reflectance efficiency is maintained indefinitely. Contrarian Metal Resources tested three InvariMatte® roofs in different parts of the United States that were in service more than 10 years without cleaning. No degradation in solar reflectance could be found. For details regarding this investigation, click here.
Longer Lifespan/Corrosion Resistance: Since zinc and copper are both reactive metals they will, depending on environmental conditions, produce oxide which depletes material thickness over time. While these metals will provide decades of service, eventually enough metal is lost to weaken joints which causes failure. Further, zinc carries the added risk of backside corrosion from trapped moisture, requiring coatings to protect the metal surface, or greater than normal ventilation. Provided the right grade is applied to match the environment, InvariMatte® stainless steel does not result in metal loss ensuring a longer lasting installation. The same is true for InvariSand™ titanium.
Fire Resistance: While any metal roof system provides good fire resistance, stainless steel and titanium’s melting points are much higher than zinc and copper, providing an added measure of protection against a range of threats, including wildfires.
Hail Resistance: InvariMatte® stainless steel has four times the dent resistance of carbon steel, which is already superior to zinc and copper in this regard. This means stainless steel lessens the risk of hail damage exponentially. Titanium has similar properties.
No Toxic Runoff: Stainless steel and titanium both have harmless oxide films that do not deteriorate, resulting in no harmful biocide runoff. This cannot be said for zinc, copper, and lead, which can contaminate the environment. Often, lead is present as a coating on copper which bears the added health risk to workers that are exposed to the material.
Fabrication Benefits: InvariMatte® stainless steel is both weld-able and solder-able allowing for best practices in joining and weatherproofing.
Paintable: InvariMatte® stainless steel is paintable, facilitating color that may be required for the design. However, it should be noted that paint will reduce solar reflectance.
Zero Discoloration or Fade: The low glare textured finishes of InvariMatte® and InvariSand™ are highly repeatable and do not degrade. This means that additions to the building or added phases to a property do not have the risk of mismatch from old versus new materials.