Finishes on Aluminum and Aluminum Clad Wood Windows: What are the differences?
There are a number of aluminum clad wood windows on the market and they are not all created equally. When comparing various manufacturers to one another, it is important to understand the differences in materials and construction that windows are made out of. The aluminum cladding can be roll form, an extrusion, or sheet material. Typically and extrusion is the thickest form of aluminum cladding available on a window. Within each of these types of cladding the paint finish that is applied to the aluminum can vary depending on the manufacturer. Thankfully the industry has created standards for windows and doors. The standards can help consumers understand what a product is constructed of.
AMMA, American Architectural Manufacturers Association, is one organization that test windows and doors. Their standards for finished aluminum cover three different categories: AAMA2605, AAMA2604, and AAMA2603. The standards require a aluminum clad window to test to different levels. A comparison of the standards can be found here. 2605 is the most stringent standard and is normally met using a 70% Kynar paint or 70% PVDF paint. 2604 is the middle standard and is met using a 50% Kynar Paint. The 2603 specification is normally met using a baked on enamel and is the lowest grade finish level in the standards. 2603 is usually the least expensive paint application and is used for interior applications. However, some window and door manufacturers use the 2603 standard as their default window paint finish and may or may not offer a 2604 or 2605 compliant finish for an upcharge. Knar is a resin inside the paint that is applied to the aluminum extrusions.
In our area along the Northern California Coastline and San Francisco Bay, we mainly supply window and door products that meet the AAMA2605 standard. Two of our products that offer painted aluminum both are painted to the 2605 standard. Within the 2605 standard there are a couple variations (2605-11 and 2605-5). One variation applies to roll form aluminum and the other applies to extruded aluminum. Marvin Windows and Doors, offers an aluminum extrusion as the cladding on their entire product line. This extrusion is then finished to the AAMA 2605-5 standard, which happens through the use of a of 70% PVDF paint. More information on Marvin’s cladding can be found on their website, under Aluminum Clad Windows for A Low Maintenance Exterior.
We also carry Fleetwood Windows and Doors which makes extruded aluminum (inside and out) products. Fleetwood offers anodized finishes and painted products that meet the 2605 standard with a 70% Kynar painted finish. Painted aluminum extrusions should meet the 2605 standard in order to perform in a coastal or sunny environment where the color is exposed to UV, salt spray, and direct sunlight.
An example of what happens when you don’t use the best finish on a Aluminum Clad or Aluminum Extruded Window and Door can be seen in the photos below. The photos were taken of a roll form clad wood patio door that was installed in 1991 in California along the Pacific ocean. The finish has not held up and is breaking down allowing the underlying aluminum to rust and corrode from exposure. When investing in windows and doors, it makes sense to buy something that has the best finish available.
Roll Form Aluminum Clad Window
When customers ask us why we carry the windows we do, finish is one of the key components. We strongly encourage any one that is purchasing a aluminum clad wood window to consider Marvin’s extruded aluminum finish. The finish comes with a 20 year warranty on the cladding and will hold up in the harshest of environments. When considering an aluminum extruded window or door, the same thing applies. Look for a product such as Fleetwood that has a 70% Kynar paint for the best finish for the harshest exposures.
Additional information on Marvin Windows and Doors and their Clad Finishes can be found on their website.
Additional information on Fleetwood Windows and Doors, Painted Finshes can be found on their website.