Glulam Building: Start to Finish – Part Two B
Welcome to our “Glulam Building: Start to Finish” series. Our goal is to provide an overview – from idea to completion – of a glualm building, from the perspective of a glulam manufacturer and designer.
Part 2B: Lateral System
A completed structure requires a complete load path for vertical loads (e.g. a way to transfer the weight of snow from roof to foundations), and a lateral system to keep the building from tipping or racking (particularly when pushed by wind of shaken by an earthquake). There are only a few options available to use glulam as the lateral system itself, much more often it relies on different materials. Therefore, the lateral system selection is important to make and coordinate with all designers early in a project.
Typical glulam lateral systems include:
Part 2B: Lateral System
A completed structure requires a complete load path for vertical loads (e.g. a way to transfer the weight of snow from roof to foundations), and a lateral system to keep the building from tipping or racking (particularly when pushed by wind of shaken by an earthquake). There are only a few options available to use glulam as the lateral system itself, much more often it relies on different materials. Therefore, the lateral system selection is important to make and coordinate with all designers early in a project.
Typical glulam lateral systems include:
- Cantilevered Columns – in this system columns are rigidly connected to the foundation, often by direct embdment, so that lateral stability of the structure is provided by the bending of the columns. While this system is simple, it is also relatively flexible. It is most commonly used for open structures like picnic pavilions (see below), which lack any walls, doors, or windows which might be damaged by excessive movement.
- Three Hinge Arch – Tudor (see below) and Gothic arches are common glulam framing systems. The arches themselves are laterally stable, but only in the direction of the arch span. In this case, glulam framing provides a lateral system only in one direction. Lateral stability is the other direction (parallel to the building ridge) needs to be provided by another system.
Fortunately, most buildings need walls for enclosure, so they can readily act as a shear wall system – either framed walls with structural sheathing, CMU, or concrete. The locations of structural shear walls should be coordinated with the glulam designer in order to confirm that lateral forces are transferred from glulam framing to walls as expected.
If you’d like to see how glulam can be apart of your structure contact us at 607-369-9341 or email us at [email protected]