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Glulam
Engineered wood is becoming increasingly popular. Glulam is the brand name under which Rosboro
(smaller supplier than market leader Trus Joist) brings their engineered wood beams to market. Similar to
TJ (Trus Joist's) LVLs, PSL and LSLs, a glulam is a type of structural timber product composed of several
layers of dimensioned lumber glued together. By laminating several smaller pieces of wood, a single large,
strong, structural member can be manufactured from smaller lumber. These structural members are used as
vertical columns or horizontal beams, as well as curved, arching shapes. Connections are usually made with
bolts and steel plates.
The superior strength of glulam allows longer clear spans than solid-sawn lumber. This opens up the design
possibilities in both commercial and residential construction. In commercial design, custom glulam beams
can span more than 100 feet. In reticulated glulam framed dome structures, glulam arches span more than
500 feet.
Glulam trusses also take many shapes, including simple pitched trusses, complicated scissors
configurations and long span bowstring trusses with curved upper chords. When designed as space frames,
glulam truss systems can create great clear spans for
auditoriums, gymnasiums, churches, and other
applications requiring large, open-floor areas.
Engineered wood is becoming increasingly popular. Glulam is the brand name under which Rosboro
(smaller supplier than market leader Trus Joist) brings their engineered wood beams to market. Similar to
TJ (Trus Joist's) LVLs, PSL and LSLs, a glulam is a type of structural timber product composed of several
layers of dimensioned lumber glued together. By laminating several smaller pieces of wood, a single large,
strong, structural member can be manufactured from smaller lumber. These structural members are used as
vertical columns or horizontal beams, as well as curved, arching shapes. Connections are usually made with
bolts and steel plates.
The superior strength of glulam allows longer clear spans than solid-sawn lumber. This opens up the design
possibilities in both commercial and residential construction. In commercial design, custom glulam beams
can span more than 100 feet. In reticulated glulam framed dome structures, glulam arches span more than
500 feet.
Glulam trusses also take many shapes, including simple pitched trusses, complicated scissors
configurations and long span bowstring trusses with curved upper chords. When designed as space frames,
glulam truss systems can create great clear spans for
auditoriums, gymnasiums, churches, and other
applications requiring large, open-floor areas.
For a 16 foot floor load, the following are equivalent:
For a 16 foot span on a roof that needs to support snow
loads, the following are equivalent:
- 4 x 14 Douglas-fir Select Structural sawn lumber
- 2-1/2 x 13-1/2-inch Douglas-fir glulam
For a 16 foot span on a roof that needs to support snow
loads, the following are equivalent:
- W8 x 10 steel beam (measures just under 8" X 4")
- 3 x 12-3/8-inch 24F Southern Pine glulam
- 5 x 11-inch 24F Southern Pine glulam
Rosboro stocks lengths up to 66 feet and depths of 6" thru 30" in 2" increments in two appearance grades:
- Architectural Appearance: Voids larger than 3/4" are filled, low laminations are repaired and all
exposed faces are surfaced. Architectural glulam is used in applications where members are exposed
to view. Widths are 31/8", 51/8", 63/4" and 83/4".
- Framing Appearance is a “hit or miss” finish and allows more irregularities than Architectural
Appearance. Framing Appearance glulam is available in widths designed to fit flush with standard wall
framing and is intended for use in concealed applications. Widths are 31/2", 57/16" and 7".