How Architects Can Specify the Right Metal Finish – Part 4

Painted Metal is an amazing product – its finish offers unmatched durability, flexibility, and color vibrancy to suit any project’s needs. However, in today’s market, product specifiers are swamped with a vast array of color and finish options. Contrasting terminology amongst manufacturers, differing warranty provisions, and varying levels of manufacturer sophistication, contribute to the complexity in the finish selection process. Inappropriate finish selection, digital representation limitations, and improper field installation practices can also translate to design visions mismatching with end solution reality. To help demystify the different elements of a painted metal finish, to encourage specifiers to select an appropriate color and finish, and to ensure design vision is translated into reality, Steelscape has created this four-part series on specifying a painted metal finish. Overall, we hope this summary provides architects with the tools needed to feel more comfortable and confident when specifying metal roofing and metal siding in their designs.

Getting the Right Product Information and Product Specification Resources – Part 4

In this section we’ll review the final key pieces of information required to ensure the right metal finish is specified. First, it is important to review any external factors that may limit product selection – this can include items such as green building requirements and local area planning restrictions. Second, understand what a complete metal finish specification should include, and finally, why physical samples should always be reviewed.

Color and finish selection can be influenced by local planning or green building programs. Certain green building programs such as LEED v4.1 or Living Building Challenge may require a minimum SRI value (discussed in part 2) for a roof surface and this may preclude certain roof colors.  The Cool Roof Rating Council manages the certification of these ratings and is seeking to expand this rating process to walls. In the future, these programs may also mandate the SRI value, and potential color, for a wall surface. Certain Homeowners Associations or planning areas may also have restrictions on the gloss or glare of products in which LRV (also discussed in part 2) should be used to differentiate between colors. Finally, some building owners, for example the Forestry Service, may have pre-approved color lists or corporate color mandates which may need to be considered.

To match a specific corporate color or a specific hue to fulfill a design vision, coaters and product manufacturers should be contacted to identify the lead time to produce these custom colors. Pre-painted metal offers the flexibility to match virtually any color, however it can involve additional administrative processing time.

Overview of LEED v4.1 Heat Island Effect and SRI requirements

Several manufacturers provide guide specifications to assist with the specification of painted metal products to ensure both designers and building owners are satisfied. Important areas often covered in the guide specifications for metal finishes include:

• Relevant ASTM specification – Specifically this will include ASTM A653 or A792, the standard for applying a metallic coating to steel to prevent corrosion. It will also include the relevant testing standards used for ensuring a high quality pre-painted metal finish that is fit for purpose. These tests including film thickness, gloss, hardness, cure, abrasion performance, paint adhesion, formability, chemical and salt spray resistance, color fade and more. The specific ASTM standards include: ASTM D5796, D523, D3363, D5402, D968, D3359, D2794, D4145, D2247, C267, D2248, D1308, B117, D714, D4587, G154 and D2244.
• Product specifics – Including product name, paint system type, SRI, texture and other relevant product attributes.
• Product preparation for installation – How the structure must be prepared for application and how the product should be stored (this avoids items such as wet stack corrosion and other premature paint issues).
• Considerations for the install process – Pre-painted metal may require care and avoiding certain practices to ensure an issue free finish once installed. This includes items such as not marking the paint with lead pencils, avoid dragging panels on top of one another, and to avoid using friction blades to cut. These specifications typically include compatible fastener and sealant types. Improper fastener or sealant selection can lead to premature corrosion of a metal surface.
• Site Clean Up – This provides an overview of how to ensure the surface is cleaned of any debris, dirt, grease from handprints or metal filings that may damage the surface if not removed.
• Long Term Roof Maintenance – Steps building owners can employ to maximize the lifespan of the installed solution. This including avoiding the accumulation of water or plant matter, or run off from dissimilar metal types, such as copper in air conditioning condensers.

There are many tools available that allow designers to quickly review and compare colors, this includes online digital swatches, color visualizers and BIM models.  However, it is always recommended to get a physical metal sample prior to product selection. This is recommended for several reasons:

• Natural Light – Digital swatches are typically pictured without a light source present. Most colors will interact differently in natural light conditions, particularly metallic colors, resins or dimensional finishes. Using physical samples to assess how a color will appear throughout different stages of day can help identify if a color will fulfill a design vision. Natural daylight, as opposed to fluorescent or incandescent light, will always demonstrate the truest color.
• Digital swatches may be inaccurate – Two key problems occur with picking a digital color – your monitor may not be appropriately calibrated, or the monitor in which the digital swatch was developed may not be calibrated. This variance can lead to actual colors that differ significantly to the way they are presented online. Digital renderings can also often fail to adequately demonstrate the depth of dimensional or translucent finishes such as tinted resins, micas and prints.
• There are only so many ways to describe a color – The number of ways a color can be described are often limited by language, whereas the options to modify a color hue are almost endless. For example, one company’s ‘Dark Bronze’ may vary significantly to another company’s ‘Dark Bronze’. These colors may differ both in terms of how dark or light they appear and the colored tint of the finish.
• Scale – If a finish is more than just a solid color, such as a print or texture, obtaining a physical sample will help identify how small or large the pattern is and how it will integrate with the building’s design from different viewing distances. It is often very difficult to identify how a color will appear from a distance compared on small digital swatches.

Physical sample evaluation

If it’s a designer’s first time using a metal finish, consider consulting with someone experienced with metal. This may be beneficial for several reason.  First, the number of metal finish options available has expanded considerably in recent years, specifically in the areas of natural finishes, textured options and low gloss matte finishes.  Experts may be able to present color family or grouping options including trim and flashing contrasts, unique finish and texture options or to relay trends in metal design and color selection. To support this need, Steelscape offers a broad range of resources to help educate designers on metal finishes including design guides, an architect support line and a fully stocked sample library. Visit Steelscape.com for more information.

On site product training

Thank you for taking the time to read through this four-part series. If you have any additional questions or suggestions for future content, please reach out using the ‘Ask Steelscape’ functionality on Steelscape.com.

To learn more about paint systems, paint warranties and paint failures, take our online course of ‘Introduction to Pre-Painted Metal’ available on AEC daily and valid for 1.0 AIA CES credit. In the next part we will discuss how to get the right product information and specification resources prior to product specification.

For more information on other current color trends, complementary palettes and other color considerations, see the Steelscape Color Design Guide and Single Skin Metal Wall Design Guide. In the next part we will discuss how to specify the right paint system based on the installed environment.

This concludes our Getting the Right Product Information and Product Specification Resources, the fourth article in our four-part series on How Architects Can Specify the Right Metal Finish. To learn more about the core constructs of a pre-painted metal finish, see the paint and metal 101 documents at www.steelscape.com/resources/document-library or visit the Architect Center. Look for our next article where we will discuss why it is important to consider batch and direction sensitivity.

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