What is checking?
Checking is a common moisture related phenomenon in wood. Checking occurs naturally in wood and is parallel to the natural grain direction of the piece. Glulam beams typically exhibit fewer and less severe checks than comparable size sawn timbers due to their relatively low moisture content at time of manufacture. It is often difficult, however, to control the exposure of glulam to the elements during shipping, storage, and erection. Checks are often observed near a glueline in a glulam member where differential drying stresses are greatest. This most often occurs near the outermost glueline where the amount of surface exposed by the outermost lamination is greatest. Checks are a natural characteristic of wood and are not normally considered to have a detrimental effect on the strength of the member.
Click here for more information about camber, species and layups.
Rosboro Custom Glulam
Convenience and Flexibility
In 2009 Rosboro opened the custom glulam plant in Vaughn, Oregon. The plant can manufacture beams up to 100' long and 53" deep and 14-1/4" wide as well as a wide range of curves. Custom section sizes are no problem including metric dimensions. Rosboro can also provide Douglas fir treated glulam to meet a specific need and also offers Alaska Yellow Cedar or Port Orford Cedar glulam when a naturally durable species is preferred over treated product. Glulam can be fabricated at the plant making job-site installation quick and cost effective and custom glulam can be shipped within 2 to 3 weeks of order.
Rosboro offers many appearances including Architectural, Industrial, Framing, Premium (Industry Standard), and Rosboro’s best appearance Premium Hand Select. Custom glulam can also be specified with a rough sawn texture.
Glulam is unique in that it can be easily cambered to suit specific load-bearing spans and offset the effects of deflection. Rosboro Custom Glulam can be ordered with straight or specified camber anywhere from a fraction of an inch up to a tight curve.
Rosboro’s standard depths include multiples of 1-1/2" such as 4-1/2", 6", and 7-1/2" as well as I-joist depth and 9-1/4" and 11-1/4" depths that match 2 x 10 and 2 x 12 joist depths. Ask your sales representitive about depths beyond 53".
Rosboro utilizes local treaters to recommend the preservative option that best fits the intended use and provide a quality treated product. Rosboro recommends oil-borne or mineral spirit based preservatives for glulam since water-borne preservatives such as ACQ and ACZA cause excessive checking and splitting. Custom Douglas fir glulam can be ordered with specified treatment to protect against decay, mold, and insect attack. Preservative treatments are selected to meet requirements of commercial, industrial, or residential applications.
Rosboro BigBeam is a high-strength glulam manufactured with a combination of dimension lumber in the core and LVL on the top and bottom. BigBeam is engineered to match standard I-joist depths and wall framing widths. It can be manufactured straight making it the ideal high-strength beam for engineered ﬂoor systems, ensuring a ﬂat, consistent ﬁnished ﬂoor or with a slight radius to offset deflection. For applications with heavy loads and long spans, Rosboro BigBeam is the ideal choice.
Rosboro Custom Glulam is certified by the APA/EWS and Independent Inspection Title 24. It also carries certification by JAS (Japan) and CSA (Canada). Code recognitions include Approval by ICC-ES Report ES2-1940, compliance with ASTM D-2559 for wet-use adhesives, inspected and certified by APA/EWS in conformance with American National Standards (ANSI) A190.1-02 and it is Los Angeles City approved. Visit our technical library for more information.