Preservative Treatment of Glued Laminated Timber

Structural glued laminated timber (glulam) offers exceptional strength and versatility for construction applications, but certain environmental conditions—such as prolonged moisture exposure, temperature ranges conducive to decay (50°F to 90°F) and contact with ground or water—can compromise wood integrity. When proper design and construction techniques cannot adequately protect glulam members, preservative treatment can help ensure long-term structural performance and durability.

This publication is designed for: architects, engineers, builders, contractors

The publication explains AWPA Use Category classifications, details organic and inorganic preservative options with their characteristics and limitations and provides treatment recommendations based on wood species and application requirements.

Key sections include:

• Applicable standards

• Intended end-use service conditions

• Inorganic and organic preservatives

• Treatment recommendations for different species and timing

• Retention and penetration levels by use category

• Field treatment procedures and fastener specifications

• Use and handling precautions with EPA safety guidelines

Published by APA — The Engineered Wood Association.