select materials suited to the application
A variety of materials are used in the fabrication of exterior-grade doors and framing, such as wood, steel, aluminum, and composite materials; each having unique properties and performance characteristics. Exposed to the elements, materials that are prone to rotting or rusting must be refinished regularly to maintain their appearance and prolong service life. This is not without cost to building owners, or without consequence to maintenance staff and building occupants. Sanding in preparation for repainting generates fine particulates that become airborne irritants. Exterior-grade paints can emit noxious fumes or harmful volatile organic compounds (VOCs). Soiled painting supplies and leftover paint present disposal issues. All of this can be avoided with alternatives to these traditional materials.
Aluminum offers excellent corrosion resistance, and can be anodized or painted to provide very durable, low-maintenance finishes. Composite materials are another alternative, with the added benefit that they can be colored throughout to eliminate any need for painting. Flush doors are available that are fabricated using a combination of aluminum and composite materials. These hybrid-type doors do not require refinishing and offer stain resistance that makes them easy to clean using green cleaners. They can also offer thermal insulating performance advantages.
good design is more than skin deep
One side of every exterior door is indoors, so if materials having the potential to emit VOCs such as adhesives and sealants were used in the door’s fabrication, exterior doors can contribute to poor IAQ. The use of structural adhesives is particularly common in the fabrication of flush doors, so emissions performance should be considered when comparing these products for green construction.
The conventional wisdom in door design holds that heavy-duty doors must be made more rigid, which typically makes them heavier. Unfortunately, doors never function independent of hardware and framing, and heavy, rigid doors subject hardware and framing components to increased wear and tear, reducing service life. When hardware, doors, or framing start to wear and go out of adjustment, doors may fail to latch properly, creating air leaks that waste energy. To be consistent with the material resource and energy conservation goals of sustainability, entrance components should be viewed as an interdependent system, and the lightest doors that will perform as required should be specified to maximize the service life of all other entrance components.
performance is what matters most
Standardized laboratory testing of specific product attributes can provide valuable insights into a product’s performance potential. Laboratory test results should be referenced to compare emissions performance, thermal insulating performance, and any other relevant product attributes necessary to evaluate manufacturer claims.
There is no substitute for actual experience with the product. It’s important that architects and specifiers get input from end users, particularly the maintenance staff responsible for maintaining entrances, to learn which products perform the best and last the longest. Ultimately, it’s the best-performing, longest-lasting entrance products that require the least maintenance that will prove to be the best choice for green construction.
