Some of the most common questions we are asked about Glulam products are about...
- Cantilever & Multi-Span Beams
- Holes / Fabrication
- Hi-Clear II
- Design Software Support
Differences in the shrinkage rate of individual laminations used is glued laminated timber tend to concentrate shrinkage stresses at or near glue lines, resulting in checks along the glue line. Checks are often confused with delamination that occurs when the glue bond is not adequate. The presence of wood fiber separation in these openings is the key distinguishing characteristic of seasoning checks. Openings due to inadequate adhesive bonding may appear as smooth wood surface separations, possibly darkened by the adhesive film with an absence of torn wood fiber.
- Protect from direct exposure to the elements.
- Avoid direct ground contact. Place on blocks to provide ventilation around the members.
- Protective wrappings should be maintained intact
- Slit bottom of wrap to allow drainage of entrapped water.
- Critical to avoid rapid lowering of the relative humidity.
- Allow glulam to slowly reach equilibrium moisture content
- Avoid directing heat from temporary heaters on unseasoned glulam.
- Design permanent heating outlets to deflect heat away from glulam members.
Checking Claim Procedure
- Contact Rosboro BEFORE any settlement is made
- Determine glulam was manufactured by Rosboro
- Provide Rosboro clear close-up and wide view photos
3. Cantilever & Multi-Span Beams
Rosboro’s X-Beam is a 24F-V4 glulam that is manufactured with an unbalanced lay-up. In unbalanced beams, the strength of the lumber used on the beams tension side (face) is greater than the lumber used on the corresponding compression side (top). As a result, unbalanced beams may not carry as much load in a multi-span or cantilever application. The load carrying capacity is reduced as the span length or cantilever length is increased.
For most residential applications where the cantilever length is relatively short, a stock 24f-V4 X-Beam can be used. As a rule of thumb, cantilevers up to 20% of the main span can be accommodated using an unbalanced beam.
4. Holes / Fabrication
For years there has been confusion in the field about whether holes can be safely drilled into or through glulam beams. Any steel or wood beam can be damaged with improper holes or fabrication.
Vertical Holes: The following formula may be used to determine the reduction in the beam's load-carrying capacity: 1.5 x (hole diameter) / (beam width) = the pounds per lineal foot reduction.
Simpson Strongtie and USP support X-Beam products with a full line of compatible hardware. Any hanger that publishes a Douglas Fir connection value can be used with X-Beam. Standard DF rated timber hardware is typically much less money than comparable glulam hardware.
6. Hi-Clear II
Rosboro Treated X-Beam is treated with Hi-Clear II a clear wood preservative intended for treatment of lumber, timbers, laminated beams, LVL and architectural wood products. The treatment provides protection for above ground, exterior application from conditions favoring insect attack and attack by wood-degrading fungi. Hi-Clear II is not approved for ground contact applications.
7. Design Software Support
Rosboro’s X-Beam Products are supported in a wide range of design software that includes isDesign™, ENERCALC™, SAPPHIRE™, StrucCalc™ as well as Weyerhaeuser’s FORTE®, JAVELIN®, and ESTIMA™, Simpson Strong-Tie.