Workshop Held on Tolerances for Surface Smoothness, Flatness, and Slope April 23, 2007

	The workshop, held on March 16th, focused on tolerances for surface flatness, smoothness and slope.

The Board’s accessibility guidelines for facilities, including those issued under the Americans with Disabilities Act, recognize conventional industry tolerances for field conditions. The Board receives many inquiries from design, construction, and code professionals on what tolerances are acceptable for a given specification. The Board is sponsoring a project to develop guidance on construction tolerances, particularly those pertaining to the slope, flatness, and smoothness of ground and floor surfaces.

As part of this project, which is being conducted by Architectural Research Consulting, Inc., a workshop was held on March 16th to identify strategies and considerations for developing this guidance. Participants included representatives from various trade associations, professional societies, government agencies, and research organizations. Discussion focused on available measurement protocols for surface flatness, smoothness and slope in relation to construction materials and methods.

Papers presented at the workshop addressed design issues, construction considerations, and findings from a study of the physical effects of wheelchair travel over uneven surfaces. Participants identified ways to advance work on establishing appropriate tolerances and measurement protocols and promoting best practices through various trade and professional associations, including the Construction Specifications Institute, the American Institute of Architects, and the American Concrete Institute, among others. This project, while currently focused on exterior routes, including ramps, will also explore tolerances for other types of construction.

For further information on this project, contact Lois Thibault, the Board's research coordinator at thibault@access-board.gov, (202) 272-0023 (v), or (202) 272-0082 (TTY).

Workshop Participants

• Associated Builders and Contractors, Inc., Bill Fairchild
• American Concrete Institute, Ward R. Malisch, P.E, PhD.
• The American Institute of Architects, William Rakatansky
• American Public Works Association, Mark Macy, P.E.
• American Society of Concrete Contractors, Bruce Suprenant
• American Society of Civil Engineers, Dr. Ernest W. Parti, P.E.
• American Society of Landscape Architects, Jon Pearson, ASLA
• Building Owners and Managers Association International, Dave Johnston
• The Construction Specifications Institute, Jennifer Han
• MASTERSPEC, Paul Brosnahan, AIA, CSI, CCS
• National Institute of Building Sciences, Nanne Davis Eliot
• National Institute of Standards and Technology, Alan M. Lytle
• US Army Corps of Engineers, Scott Wick, RA, LEED AP

For the Access Board:

• Lois Thibault, Access Board Research Coordinator
• Doug J. Anderson, Access Board Public Member
• David Kent Ballast AIA, CSI, Architectural Research Consulting
• Dr. Rory Cooper, Ph.D., Department of Rehabilitation Science and Technology
• Coleby D. Cyrtmus, Hitt Contracting, Inc.
  

Presented Papers:

• Initiative on Dimensional Tolerances in Construction Surface Compliance Design Issues by David Kent Ballast AIA, CSI
• Constructability Considerations in Walking/ Rolling Surfaces by Coleby D. Cyrtmus/Sr Project Superintendent- HITT Contracting Inc.
• Longitudinal Assessment of Vibrations During Manual and Electric Powered Wheelchair Driving Over Selected Sidewalk Surfaces by Erik Wolf, M.S., Rory A. Cooper, Ph.D., Jonathan Pearlman, M.S., Shirley Fitzgerald, Ph.D., and Annmarie Kelleher, M.S.