The beauty of Aluminum Composite Material (ACM) is noticed at first sight; its strength, however, takes years to fully appreciate. As much as we want to protect and cherish our exterior designs, elemental damage and physical impact are a natural part of a building envelope’s life.
Fortunately, Aluminum Composite Material is a notably strong cladding material, and with it, you can enjoy an exterior that endures whatever the world has to throw at it. This article highlights some of the protective qualities of Aluminum Composite Material and the standardized tests that give proof to the claims.
The Protective Qualities of Aluminum Composite Material and The Standardized Tests
When we think of strong materials, the first thing that comes to mind is impact resistance. We will get to that soon, but first let us take a look at another common enemy of your building: elemental damage. Many of the tests are standardized by ASTM International, an organization devoted to ensuring performance of a wide range of products.
Heat and Sunlight
We might get a tan from the sun, but bright rays can suck the color out of many materials. Even the darkest or brightest of colors can fade over long exposure to UV light, and if ACM’s finish could not stand the heat, their bold look would be short-lived.
A common method for testing how cladding weathers the sun involves exposing Aluminum Composite Material to the famously hot sunshine of southern Florida for a period of ten years. Panels are even tilted at a 45 degree angle, to be sure it is staring right into the sun.
When testing UV resistance, color change is measured with units called Delta E, calculated from a formula that compares a pair of color scales. To put things into perspective, Delta E has to reach 2.3 before the naked eye can detect any variation. This testing is classified as ASTM D2244.
ACM from Alcotex–a popular manufacturer–faced this ten year test of direct UV exposure, and saw at most 5 Delta E units of change. Alpolic–another manufacturer in the space–passed this test with similar results.
But, as they say in Florida, “it’s not the heat that gets you, it’s the humidity!” There is a test for that too. ASTM D2247 is a humidity test that places materials in atmospheres of 100 percent relative humidity. Alcotex reports that their Aluminum Composite Material went 4000 hours in this environment–at 100 degree Fahrenheit heat–and lived to tell the tale. The paneling suffered not a single blister! Alpolic’s comparable product only suffered a blister rating of eight (ten being no creepage at all).
Corrosives eat away at materials over long exposure to a variety of elements. When you are seeking a reliable cladding product for your building, this simply cannot happen. That is why ACM has been layered, coated, and finished with corrosion resistance at the forefront. This heightens one of aluminum’s key attributes: this is a metal that–unlike others, such as steel–will not rust.
So how is corrosion resistance measured? Neutral salt spray testing, or ASTM B117 is a commonly used assessment, in which a material is exposed to a saltwater mist composed of 5 percent sodium chloride. Alcotex’s ACM went 4000 hours in a salt spray cabinet, and came out with but a slight 1/16” of corrosion creepage: a blister rating of eight. This reaffirms the key selling point of ACM, it will hold well up against corrosion!
Adhesives can rip the finish and coating off lesser materials when it is removed. To assess ACM’s resistance to this, ASTM D3359–better known as the tape test–is a reliable evaluation. #600 Scotch tape is known for its reliable hold, but when Alcotex slapped it onto their ACM and pulled it off, the adhesive took no coating with it.
Every building must be proactive in protecting against fire. It does not take much–as little as a spark–for fire to prove disastrous. Aluminum Composite Material has come a long way in this regard, with most manufacturers offering products with a Fire Retardant Core (FR).
Alcotex’s FR ACM earned a class A rating under ASTM E84, in which a sample was hung over burners in a box known as a Steiner Tunnel. Alpolic’s product also passed class A testing. ASTM E84 is a good preliminary indicator of fire resistance, though it fails to ultimately emulate the many factors of a real life fire.
Both manufacturers also submitted their products to NFPA 285, which specifically tests exterior products with plastic cores. This standardized test assesses the panels in a simulated multistory setup, to best indicate real world results. Both Alcotex and Alpolic’s offerings passed this certification. In Canada, CAN/ULC-S102 (similar to ASTM E84) and ULC CAN-S134 (similar to NFPA 285) are the standards for fire testing ACM. Alpolic’s FR ACM met the conditions of both these assessments.
It is important to note that even if a material is fire resistant, that does not mean it is fireproof. FR paneling–according to Alpolic’s testing–ignites at 400 degrees C. These cores are designed to slow down the rate of combustion, not prevent it entirely. Due to this, ACM cladding is not recommended to exceed 40 feet, or four stories from the ground. In Ontario, this is required by code.
Now to the fun part: physical strength. Damage caused by impact is explicit and visible, in comparison to elemental, and thus is the most exciting way to test the durability of Aluminum Composite Material. Bring out the missile!
The missile test, classified as ASTM E1996, is the widely adopted standard for assessing impact damage. It is used to check the resistance of many exterior elements, from windows to cladding, and was developed to simulate the worst a hurricane could throw at your building.
Missile tests involve shooting a projectile at the specimen, with five levels of extremity based on the intended use of the material. Projectiles range from a two gram steel ball (Level A) to a nine pound two by four (Levels D and E). Ok, it might not be the missile you were imagining, but this test packs a punch!
Alfrex, a notable manufacturer in the industry, performed a Level D missile test on Aluminum Composite Material installed as a rainscreen. This means that there was an air cavity between the paneling and the substrate: the ACM had to withstand the test with little support. Level D is known as the “Large Missile Impact Test” as it uses the largest and heaviest projectile recommended by ASTM E1996. Testers shot the ACM with a nine-pound two by four flying at 50 feet a second. We cannot say what became of that block of wood, but the ACM was left standing with no indication of penetration or rupture.
The fact that the projectile could not create an opening in the ACM is critical. If you have ever opened your window on a windy day, you know that the resulting tunnel can shake your entire house. Now imagine there are 80 kilometer per hour winds outside (the highest speed 2012’s hurricane Sandy reached in New York alone), and there is a gaping hole in your exterior left by a fencepost. ACM, based on these tests, can mitigate this risk greatly. This element is so important that ASTM E1996, the missile test, is required by code in many regions.
Even if you live somewhere not plagued by hurricanes, tornados and storms are still capable of launching projectiles at your building.
The good news is that Aluminum Composite Material is tested based on worst case scenarios, and as a result is reliable against many of life’s common threats to your building. Simply put, if the neighborhood kids can throw a baseball with the force of a nine-pound piece of wood going 50 feet a second, they ought to be playing in the major leagues.
Whatever the world tries to throw at your building, Wiedehopf wants you to have an exterior you can put trust in. This is why we are strong proponents of the durability and strength of Aluminum Composite Material, a cladding solution you can count on in a variety of situations: ranging from commonplace happenings to worst-case scenarios.
Every environment, use case, and building has its own unique durability needs, yours included! To get into the specifics of your next project, and explore the lasting protection you can enjoy with ACM cladding, be sure to connect with one of our representatives. +1 (905) 761 9791 is your number to call for a no-obligation discussion about Aluminum Composite Material cladding’s potential for your commercial, industrial, or residential property.