2. LVL STRUCTURES IN FLOORS, WALLS, ROOFS AND IN SPECIAL APPLICATIONS Figure 2.68. Sole plates from LVL. Thin plates reduce settling perpendicular to grain and reduce cold bridges. Left: LVL-C sole plates may be extended beyond the edge of foundation to reduce cold bridges in the structure. It is recommended to connect the anchoring hold-downs to the studs. 2.4.6 Sole plates, bottom cords, top cords and top binders LVL-P or LVL-C boards function flatwise as sole plates, bottom cords under wall studs, and top cords or top binders above studs in timber frame walls. The members can be designed to thinner thicknesses than solid wood, e.g. 45 mm, as they are dimensionally stable and not sensitive to twisting or cracking. Smaller thickness reduces settlement of the frame in the perpendicular to grain direction. LVL sole plate and bottom cord sizes also make good combinations with I-studs in timber frame walls. For the best wall bracing performance it is recommended to connect the hold-down anchors to the wall studs. LVL-C sole plates can be extended beyond the edge of the concrete foundation slab to create a drip edge. This helps to insulate the foundation, e.g. rendering panels, and to avoid cold bridges. As compression perpendicular to the grain is lower flatwise compared to an edgewise orientation, an LVL product with higher strength made from pine veneer can be supplied for this application to help reduce the cross-section sizes of highly loaded studs, e.g. next to windows. The need for treatment against insects or decay is to be verified according to national requirements. However, if a bitumen felt strip is installed between the sole plate and the concrete foundation service class 1 conditions are met for the sole plate and chemical treatment is usually not mandatory. 2.4.7 Window frame boards Long and straight LVL-C boards offer a practical solution for the installation of window elements or other cladding elements in concrete buildings. The boards are extended beyond the concrete frame to create a flat and aligned surface for the facade and to compensate the tolerances of the main frame. This saves time and labour costs and improves the building quality. Wedge anchors can be used for the connections. Board sizes depend on the structure of the facade, in the example of Figure 2.69. the size is 39x260 mm. 2.4.8 Bracing panels Robust LVL-C panels are suitable for panel bracing of timber frame walls and beam & post structures when high capacity is required or there is only limited space for the bracing structure, e.g. due to large window openings. Panel bracing simplifies the structure, as trusses or diagonal bars are usually not necessary. LVL-C panels up to 75 mm thickness allow large frame spacing without risk of buckling the bracing panel. In timber frame walls the LVL-C panels are screwed or nailed to the studs and to sole and top binders which together form the diaphragm. The thickest panels or multiple-glued elements can act as bracing columns when they are anchored to the foundations. LVL-C is available in panel widths up to 2500 mm. Wide panels reduce the number of joints to be nailed or screwed, thus reducing installation work. LVL-C panels also provide an ideal solution for higher than normal wall heights. Tables 2.1 and 2.2 show the capacities of 1.2 m and 2.4 m wide single panel sections installed in wooden frames calculated according to method A of Eurocode 5, subsection 9.2.4. Multiple sections are summed together to get the total capacity of a wall. Sections with openings are not taken into consideration, except for the transfer of horizontal forces to adjacent sections. Anchoring 92 LVL Handbook Europe
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