ANSI/AWI SMA 0643 – Wood Stair, Handrail, and Guard Systems

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In our recent podcast, Jeff Brown, Director of Education at the Architectural Woodwork Institute (AWI), and Hunter Morrison, Technical Director at AWI, discussed ANSI/AWI SMA 0643 – Wood Stair, Handrail, and Guard Systems. They were joined by Doug Adams, who is the owner of Florida Stairworks and Carpentry, and the leader of the Quality Standards Committee at the Stairbuilders and Manufacturers Association (SMA).

In this accompanying blog post, we explore the contents of the new standard, how it came about, and how it improves on its predecessor in the Architectural Woodwork Standards 2nd Edition (AWS2).

About ANSI/AWI SMA 0643 – Wood Stair, Handrail, and Guard Systems

Developed in partnership with SMA, ANSI/AWI SMA 0643 – Wood Stair, Handrail, and Guard Systems has replaced AWS2 Section 7 – Stairwork & Rails. It came into effect on August 15 2021.

“Over the last several years, AWI has been continuing to update and revise our suite of standards,” Hunter explains. “Partnering with SMA, who are the industry experts, made the most sense in order to provide a complete, accurate, robust standard for this section of the industry.”

The standard provides aesthetic and performance standards for the manufacture and installation of interior wood stair, handrail, and guard systems for residential and commercial applications. That includes guard in-fill systems, stairs, rails, and components of metal, glass, and cable.

What is and isn’t included in ANSI/AWI SMA 0643?

This standard covers products specified under CSI MasterFormat Division 06 43 00 Wood Stairs and Railings. It contains information on materials, aesthetic requirements, fabrication, and installation of stairs.

However, ANSI/AWI SMA 0643 doesn’t cover substructures of materials other than wood. These are instead covered by CSI MasterFormat Division 05 00 00 – Metals, Division 06 50 00 – Structural Plastics, and Division 09 50 00 – Resilient Flooring.

Most AWI standards refer to ANSI/AWI 0620 – Finish Carpentry/Installation for their installation requirements. But ANSI/AWI SMA 0643 features its own installation section. That’s because stair parts follow a separate building code, structural items, and connections under the National Fire Protection Association’s Life Safety Code.

ANSI/AWI SMA 0643 Section 3.6 Installation divides installation into:

  • 3.6.1 Field Assembled Stair Components
  • 3.6.2 Stairs, Shop Assembled
  • 3.6.3 Guard and Handrail Installation
  • 3.6.4 Fittings
  • 3.6.5 Guard, In-Fill
  • 3.6.6 Well-Hole Trim

As with other AWI Standards, this standard has a default aesthetic requirement of Custom grade. This applies in the absence of specification. However, if the architect specifies another grade in the specification documents or project contract, this must be followed instead.

How has ANSI/AWI SMA 0643 improved on AWS2 Section 7?

AWS2 Section 7 included a total of nine pages. Of these, only three contained information relevant to the creation of stairs and rails.

As Doug Adams describes it:

“The old standard was ultra-vague and basically allowed the competition to do anything they wanted. When it came to high-end projects, we got a lot of disputes and a lot of questions were asked. So for years the SMA wanted to make a standard that was more robust.

ANSI/AWI SMA 0643 – Wood Stair, Handrail, and Guard Systems goes from the old nine pages to 44 pages. It’s a lot more robust, and is a great tool that architects and all members of the AWI and the SMA can use.”

The new standard uses AWI definitions for key terms, and includes items such as railing-to-wall connections and structural items. It also specifies the number of staves in a tread for Premium, Custom, and Economy grades, including where they can and can’t be located.

In addition, ANSI/AWI SMA 0643 went through the ANSI process, and as such is a public consensus document. Volunteer groups had the opportunity to review the standard and offer improvements. This ensured openness, balance, and due process, which helped create a stronger standard that meets the needs of the industry.

“Getting people’s buy-in and acceptance is one of the most important things to do,” Jeff adds. “That way, the industry can provide the best-quality products that we possibly can.”

As an ANSI document, AWI and SMA must also update this standard every five years. This ensures that it conforms to changes in the industry, including advancements in machinery and tooling.

Who needs to be aware of ANSI/AWI SMA 0643?

Any party that specifies, fabricates, or installs wood stair, handrail, and guard systems needs to have a good understanding of ANSI/AWI SMA 0643.

The design professional has all normal responsibilities in specifying woodwork, including materials, grain directions, and finishes. But their most important job when specifying wood stair, handrail, and guard systems is to comply with applicable code requirements. When no code exists, they should comply with the live load requirements of the International Building Code as published by the International Code Council.

The woodworker must also be aware of the requirements of ANSI/AWI SMA 0643, as well as the project’s aesthetic grade and any other specification made by the design professional. These items could affect the bidding cost or construction method, and so must also be communicated to the estimator, engineering team, project manager, purchaser, and installer.

In particular, woodworkers should take note of:

  • Changes to the requirements for staves, treads, and risers. For example, in this new standard, the number of staves was reduced for the Premium grade
  • Grain matching for joints and rail sections
  • Guard and handrail attachments at the walls
  • Glue lines and rail fittings. For example, the top ply and easement have to be far down from the top of the rail. That way, when the rail is shaped and the profile is added, there’s no glue line breaking through the surface

Read our guide to the AWI Standard of architectural woodwork to find out more about ANSI/AWI SMA 0643 – Wood Stair, Handrail, and Guard Systems, as well as other woodworking standards.