Effect of Large Diameter Horizontal Holes on the Bending and Shear Properties of Structural Glued Laminated Timber (Glulam)
Technical Note
Glued laminated timber (glulam) beams are highly engineered components manufactured from specially selected and positioned lumber laminations of varying strength and stiffness. These fabricated beams are often specified where a certain span, strength and/or stiffness is required. As such, glulam beams are generally designed for and used in applications where they will be highly stressed under design loads. For this reason, caution should be used when making any field modifications such as notching, tapering or drilling not shown on the design or shop drawings.
This publication is designed for: glulam manufacturers, architects, builders, engineers
However, in the structural design phase or in the field, some horizontal holes exceeding the guidance provided in APA S560 may become a necessity. This publication provides an analytical tool for those conditions through engineering equations and supplement hole placement requirements.
Key sections include:
Limitations
Effect of horizontal holes on the bending capacity
Effect of horizontal holes on the bending stiffness
Effect of horizontal holes on the shear capacity
Hole placement requirements
Published by APA — The Engineered Wood Association.
