See, Timber preservatives for more information. If used for in- ground applications, LVL should be treated with preservatives to protect against decay and infestation. LVL may be subject to decay if there is a high moisture content or if it is used in an unventilated area. Curved or tapered members can be cut although these are more expensive. LVL beams are usually straight as the most cost-effective production method is to cut a number of straight members from one sheet. They can then be cut to the required sizes. Veneers are then coated with an adhesive (such as phenol formaldehyde), and heated in a continuous press. Once dried, the edge of the veneer is scarfed for a uniform thickness at the joints. Veneers are then dried to a target moisture content of between 8-10%.īefore being laminated, the veneers are dried and then oriented in the same direction. The veneer is scanned by camera for defects, analysed for moisture content and then clipped to a width of approximately 1.4 m by a rotary clipper. A lathe then peels the logs into veneers – thin slices of wood, usually thinner than 3 mm. Once logs have been debarked, they are conditioned in hot water for 24 hours. LVL is covered by British Standard BS EN 14279:2004+A1:2009 – Definitions, classification and specifications. Its high tensile strength relative to sawn timber means it is also commonly used for trusses. The veneers that make up LVL are oriented in the same direction, making it particularly suitable for beams, and its length, depth and strength make it effective at carrying loads over long spans. As an engineered product, LVL is also less prone to shrinkage or warping and is able to span longer distances and support heavier loads than regular timber. By reducing solid timber’s natural flaws, such as strength-reducing knots, LVL has good strength, uniformity and durability. It is manufactured by bonding rotary peeled or wood veneers that have been sliced thinly under heat and pressure.įirst developed in the 1970s, LVL is used as a cost-effective and sustainable building material that provides high structural reliability and strength. Laminated veneer lumber (LVL) is a type of high- strength engineered timber that can be used as an alternative to solid timber, concrete and steel for structural applications. 3 Related articles on Designing Buildings.
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