How To Specify Glulam Exterior Grade?

This text provides information on Douglas-fir glue-laminated timber (glulam) and its use in various projects. It discusses the structural dimensioning of glulam, its application in industrial, commercial, and residential structures, and its use in exterior applications. The text also discusses the use of exterior adhesives like resorcinol adhesive and the importance of protecting glulam under a roof when used outdoors.

The text also discusses the use of lumber species and grades for glulam in various layup combinations, with framing and industrial grade appearance glulam typically used in concealed areas. Architectural grade glulam is used as a façade material or exposed element. National building codes require the use of naturally durable species or pressure preservative treated wood in exterior applications.

Glulam is available in various appearance grades and stock dimensions, with straight lengths using 45mm laminates and curved ones using 33mm laminates. The third method of specifying glulam grades is to list the required allowable stresses for the members, such as bending stress, shear stress, modulus, and knot holes.

Exposed surfaces should have all knot holes and voids measuring over 3/4 in. Glulams rated for exterior use are special order and require special order. Glulam beams are made with exterior-grade or wet-use adhesives suitable for various interior and exterior applications.

In summary, glulam is a versatile and durable material that can be used in various construction projects. Its use in exterior applications, interior applications, and exterior treatments contribute to its strength and durability.

What is the difference between V4 and V8 glulam?

Glulam beams are available in two distinct layup configurations: balanced and unbalanced. Balanced layup is optimal for continuous span and cantilevered applications, while unbalanced layup is better suited for simpler concepts. The implementation of quality-driven manufacturing processes eliminates the occurrence of shrinkage and warping, while the application of rigorous testing ensures the production of a durable, dependable, and safe product.

What is architectural grade glulam?

Timber Technologies’ architectural-grade Glulams feature a smooth, aesthetically pleasing surface with voids exceeding ¾” filled with wood-tone filler or putty. The surface is sanded or planed, the edges are eased, and the product is intended for installation in locations where it will be visible. It should be noted that the dimensions of these beams differ from those of standard grade beams due to the additional machining that they undergo. The standard widths are 3 1/8″, 5 1/8″, 6 3/4″, and 8 3/4″.

What does the E mean in glulam?

The “E” symbol indicates that the majority of laminations necessitate machine testing for stiffness. In contrast, the lowercase letters indicate the grade utilized for flexural (bending) members, compression members, and tension members.

What are the different types of glulam beams?

Custom members are typically specified for non-residential applications where long spans and heavy loads control design. Common custom shapes include straight, curved, pitched, radial, and tudor arches. Glulam beams manufactured by APA members are certified with the APA Mark of Quality, indicating a commitment to rigorous quality verification and testing. The APA trademark is recognized by all major model building codes. The Glulam Product Guide, Form X440, describes APA trademarked glulam, addresses design considerations, and includes a specification guide.

Can glulam be used externally?

Glulam, a construction material, is manufactured under controlled conditions in Sweden by certified manufacturers. It is used for both interior and exterior use, but should be protected under a roof. Glulam comes in various appearance grades and stock dimensions, with straight lengths using 45mm laminates and curved ones using 33mm. The wood is high-quality, strength-graded Swedish spruce. The standard SS-EN 14080 sets requirements for constituent components and minimum requirements for load-bearing structures. Glulam is available in various appearance grades and stock dimensions.

What does V4 mean on glulam?

The Douglas fir member with a bending stress of 2400 psi is specified using a visual grade of DF 24F-V4, where the V represents a visual grade, as opposed to an E-rated grade, which employs the use of an “E” in the second term.

What is 24F V4 glulam?

The Rosboro X-Beam™ 24F-V4 glulam is an engineered wood product that offers a cost-effective solution for various framing applications, including exposed and concealed. It can be seamlessly integrated with both EWP and conventional framing systems.

How to specify a glulam beam?

Glulam bending members are specified based on their maximum allowable bending stress, with 24F and 26F designations indicating different stress levels. These stress levels are achieved by varying the percentages and grade of higher quality lumber in the beam layup. The use of different species may also result in different stress designations.

Visual vs. mechanical grading is used to identify the lumber used in the beam. For example, an unbalanced 24F layup using visually graded Douglas-fir lumber is identified as a 24F-V4. A 24F-E4 beam would indicate a mechanical graded lumber. The number “4” further identifies a specific combination of lumber used, assigning a full set of design stresses.

Glulam beams are typically installed with the wide face of laminations perpendicular to the applied load, known as horizontally laminated members. If the member is rotated 90 degrees, the load is applied parallel to the wide face of the laminations, resulting in a vertically laminated member. Glulam members have different tabulated stress properties depending on their orientation.

What are the 2 grade categories for glulam?

The industry has historically distinguished four “grades” for the finished appearance of glued laminated timber, as follows: The four grades of glued laminated timber are as follows: Premium, Architectural, Industrial, and Framing.

Are Glulams exterior rated?

Treated Glulams can be used for most exterior applications, such as decks, large pergolas, awnings, and covered porches, as long as load and span requirements are in line. However, they cannot be used for marine projects like docks. Cut or drilled edges should be sealed with copper naphthenate (copper coat) to protect against rot and decay. Glulams can also be painted or stained with an oil-based product, although this is not necessary.

How do you treat glulam for exterior use?

Hi-Clear II, a clear industrial wood preservative, is employed for the pressure treatment of glulam beams, particularly those intended for use as raised deck beams in above-ground exterior applications. The treatment results in a light honey-colored finish, thereby ensuring predictable and long-term performance without affecting the beam’s structural integrity. The honey-colored stain enhances the visual appeal of the beam.