Handling Glulam Beams

Tips and guidelines on working with glulam beams on the jobsite.

Storage in the Yard and Jobsite

Pre-Installation

Repair (if needed)

Post-Installation

Rosboro Glulam

Glulam Terms and Species

Terms

Unbalanced Glulam Beams

Unbalanced Beam

In terms of strength, the outer tension zone is the most critical section of a glulam beam. In unbalanced beams, the tension side has higher quality lamination than the compression side, allowing a more efficient and economical use of timber resources. To assure proper installation of unbalanced beams, the compression side is clearly stamped with the word "Top". Unbalanced beams are intended primarily for simple span applications, but can be used in multi-span and cantaliever applications.

Balanced Glulam Beams

These members feature symmetrical lumber quality to about mid height. Balanced beams are used in continuous-span and cantilevered applications where both top and bottom may be subject to flexural tension. They can also be used for single-span applications, though unbalanced beams are more efficient in this capacity.

Camber DiagramCamber

Among engineered wood products, glulam is unique in that it can be easily cambered to suit specific load-bearing spans and decrease the effects of deflection. The glulam industry recommends that roof beams be cambered for 1-1/2 times the calculated dead-load deflection. This amount will generally assure that the beam maintains resilience under load for many years, which may not be true for non-cambered wood products.

To achieve a level profile it is recommended that floor beams be cambered for 1.0 times the calculated dead-load deflection. Most residential applications require very little or no camber, which in turn makes Rosboro glulam the ideal choice. For example, Rosboro's standard camber is 5000-foot radius, which is nearly flat.

Rosboro glulam products are often distributed alongside other manufacturers products. We have found that we can best serve the industry by supplying a 5,000 foot-radius glulam. Some other manufacturers may produce their beams with anywhere from zero to 3,500 foot-radius camber. As the table below clearly indicates, when the manufacturing tolerance is taken into consideration, the actual difference between the values is very close at distances less than 26 feet, which represents the majority of residential framing beams.Camber Table

Species:

Douglas fir (DF)

Douglas fir, the predominant framing material in the west, is highly regarded for its dimensional stability and superior strength-to-weight ratio. Its relative density provides excellent nail-holding characteristics.

EWS Combination Balanced or Unbalanced Species Tension
Fb (psi)
Compression
Fb (psi)
Horizontal Shear
Fv (psi)
MOE 106
24F-V4 Unbalanced DF 2400 1950 300 1.9 True
24F-V8 Balanced DF 2400 2400 300 1.9 True


Alaska Yellow Cedar (AYC)

A tough, solid and durable tree, Alaska yellow cedar is noted for its natural oils that make it highly resistant to decay and insect attack. The wood is fine in texture with a straight grain and uniform yellow coloring.

EWS Combination Balanced or Unbalanced Species Tension
Fb (psi)
Compression
Fb (psi)
Horizontal Shear
Fv (psi)
MOE 106
20F-V12 Unbalanced AYC 2000 1400 265 1.5
20F-V13 Balanced AYC 2000 2000 265 1.5


Port Orford Cedar (POC)

Rated strongest among cedars, Port Orford cedar offers exceptional decay resistance due to natural oils that protect against moisture and microorganisms. This respected species has been used for everything from Japanese Buddhist temples to high-performance sailboats.

EWS Combination Balanced or Unbalanced Species Tension
Fb (psi)
Compression
Fb (psi)
Horizontal Shear
Fv (psi)
MOE 106
22F-V/POC1 Balanced POC 2200 2200 265 1.8
22F-V/POC2 Unbalanced POC 2200 1600 265 1.8