How Strong is the Framing in Your Home- Did You Know

What does APA do? One of APA's primary functions is quality assurance. The APA and APA EWS trademarks appear only on products manufactured by association member mills and signify that the manufacturer is committed to APA's rigorous program of quality inspection and testing. What is "engineered wood" "Engineered wood" is a relatively new term that means just what it says: wood products that are engineered. Plywood is considered to be the original engineered wood product and has been used for structural applications since the 1940s. Since then, other products have been developed which fit into the engineered wood family: glulam, OSB, and wood I-joists are some that are represented by APA and EWS. "Engineering" occurs during the manufacturing process, where wood components are combined with adhesives to form structural members that maximize the properties of the wood. The term "engineered wood" also relates to the capability of these products to be used in structural, or "engineered" applications. Many engineered wood products are used in the construction of buildings, while some are used in other engineered applications like materials handling and transportation, and even for the construction of highway bridges. TESTS CONDUCTED DURING THE “YOUR NEW HOUSE” SEGMENT Post Flexural Test The purpose of this test is to determine the bending and stiffness “signatures” of wood structural panel products. During initial panel qualification this information is used to develop a target mill specification. During subsequent quality assurance checks this target is used as a base line to insure the ongoing quality of member products. This information can also be used to determine the product’s design bending strength and stiffness values. What is unique about this apparatus is that it is designed to determine the panel’s maximum strength at its weakest location. More traditional bending tests induce a bending stress that is a maximum at one or two points only in the panel and less-than-maximum at all other locations. Thus, just a small area is being “tested” at the maximum load. If the weakest point in the panel just happens to be at that point, then the test will give you good results. The Post flexural test, on the other hand, places a uniform maximum bending stress – called bending moment – over the middle ½ of the panel’s area. This provides a greater assurance that the maximum moment will be felt by the weakest location in the panel. In addition, this method provides a better “average” stiffness reading for the panels tested. The reason we conduct these tests is to determine the design values for panel products in the most accurate manner possible. The success of our efforts is best evidenced by the fact that our test values and methods are the accepted standard for the industry, and have been so for over 50 years. Finger Joint Tension Test At this location we have a Metriguard tension testing machine. This apparatus is used to destructively test the finger joints used to end-join lumber. These joints effectively making short pieces into long pieces. Lumber so joined is used for a variety of products that range from studs, to the very choicest grades of structural lumber used as tension lamination stock in glulam beams. In addition to being very environmentally friendly by reducing waste – turning unusable “shorts” into high value “longs – such joints make it possible to design and build glulam beams that are from 20 to 120 feet long, and longer. The goal of this testing is to verify the quality of the gluebond at the finger-joint location by measuring its capacity and comparing it with a known value. It is not enough to simply glue the joint together, the strength and quality of the joint must be ascertained and maintained throughout production. This machine grips the member with the joint to be tested between the jaws/grips of the machine and applies a tensile or “pulling” stress across the joint. The Metriguard has a “pulling” capacity of 200,000 lbs. The relationship between this test and the performance of wood structures in high wind and earthquake events is to insure that there is an adequate factor of safety between the ultimate capacity of the elements of the structure and their design levels. As the joint has the potential for being a “weak link” in the member/structure, it must be well understood and carefully monitored. This machine gives us this ability. MORE FROM YOUR NEW HOUSE Featured videos: /playlist/PLjTMbsoHW2eiqktEDbaQunVDuiTidxPxd Great DIY Projects from Your New House: /playlist/PLjTMbsoHW2ejNSy9ywo1mKiGaSXuTsEgE Quick Tips: /playlist/PLjTMbsoHW2eh4zI-dJCevBTEdY5ioSAPQ Gardening and Landscaping: /playlist/PLjTMbsoHW2ejdcWzNkAARBzUQDvT3W1ME Adventures in Homebuilding: /playlist/PLjTMbsoHW2ehA9bTrvQ58AHfE_utaBCLc

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