GL17
Mid-tier glue-laminated timber grade with approximately 17 GPa modulus of elasticity, suitable for longer spans and higher-load structural beams.
A higher glulam grade under AS/NZS 1328.1, typically achieving a mean modulus of elasticity of about 17 GPa and a characteristic bending strength near 42 MPa. GL17 is widely used for longer-span ridge beams, garage lintels, and architecturally exposed beams. The higher stiffness allows shallower beam depths than GL13 for the same span and load. Laminations are bonded with Type I adhesive complying with AS/NZS 4364, suitable for permanent structural applications. Design values are referenced in AS 1720.1. For procurement, GL17 is widely stocked in standard sizes and lengths and is generally available in straight beams for residential portal-frame applications. Specify the appearance grade and any preservative treatment required for external use.
Values and references on this page are indicative and drawn from common industry sources. Always verify the current AS/NZS standard, manufacturer data sheet or NIAA policy publication before relying on figures for design, specification or compliance work.
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