Minnesota Department of Labor and Industry Orange bar
Minnesota Department of Labor and Industry

Opinion: Pressure treated wood




Pressure treated wood


Code: 1994 UBC Section 2317

Submitted By:

MN B. O. Uniformity Committee

Approved By:

Thomas R. Joachim, State Building Official

Issue Date:

July 22,1996


What is the minimum required percent of CCA retention in treated wood and in what locations can it be used?


The minimum required percentage of retention for CCA treated lumber (the most common treatment in this area) is .25 for above ground, .40 for ground contact, and .60 for All Weather Wood Foundation Systems. See UBC code sections 2317.2, 2317.3, 2317.4, 2317.5, 2317.6, 2317.8, 2317.9, and 2317.12 for areas of use.

Committee comments:

The standards for treated lumber have been removed from the 1994 U.B.C. AWPA and AWPB Standards are referenced in UBC 2303.1. These standards are revised for 1995 and went into publication in October 1995.

In reference to UBC 2317.2, ground contact is stated and, therefore .40 retention is required. In UBC sections 2317.3, 2317.4, 2317.5, 2317.6, 2317.8, and 2317.9, above ground use is permitted with .25 retention.

CCA treated lumber is the most common treatment process in this area. For other treatment processes see AWPA Standards C1-95, C2-95, C3-95, C15-95, C22-93 and C23-94.

Adopted by committee November 8, 1995 and approved (as amended) at the 40th Annual Institute of Building Officials on January 12, 1996

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