Pallet rack anchors are mechanical fasteners used to connect a rack system to a building. Their purpose is to secure pallet racks and resist constant antagonizing forces such as: overturning forces caused by earthquakes, winds and narrow/tall racks, accidental impact forces on the bottom end of columns (i.e., from a forklift) and shear forces (horizontal reactions) reducing the barring capacity of the rack. Should the anchor fail to withstand these attacking forces, the consequences could result in large bending forces on the upright, affecting the overall stability of the system and, in the worst of cases, resulting in a collapse. To avoid this, it’s key to select the right anchor type based on the facility's different conditions and the rack type.
Wedge Anchors, a popular type of anchors, are manufactured from carbon steel, hot-dipped galvanized, stainless steel, or zinc-plated steel. These fasteners are mostly used in solid concrete and cannot be removed if you decide to rearrange your pallet racks because they will damage your floor if you do so. Concrete Strike Anchors are impact-expansion form anchors, also used in solid concrete, and they should not be installed in any other type of masonry material, given their mechanical properties. Screw Anchors are a much less common type of fastener found in warehouses. They are used for temporary or permanent anchoring as they can be removed and installed in concrete and masonry. Lastly, we have Sleeve Anchors, ideal for light to medium-duty anchoring in concrete and masonry. No matter the type of anchor you choose, all can be found in various diameters, lengths, and thread lengths.
A rule of thumb is that the broader the diameter and the deeper the embedment, then the greater the strength of the anchor. So, it’s important to check local building codes or have an engineer determine the bolt sizes, given that several factors need to be considered: the hole size of the upright’s baseplate, seismic activity, and the area where the anchor is to be used. Additionally, the thickness of the flooring material, the mechanical properties of the flooring material, and the levelness of the floor should also be considered in case shims are needed.
The ANSI/RMI standards state that all rack columns should be anchored with at least one anchor per upright column. Depending on the anchor type, two anchors can be installed to prevent the column from pivoting upon impact. When the user cannot correctly anchor the rack, it is recommended to verify with the rack manufacturer’s engineers for other ways of anchoring the system while keeping the structure safe for use.
Bolts and anchors must be properly tightened to the minimum recommended torque specified by the manufacturer. It’s typically 40 ft-lb for 3/8’’ anchors. Inadequate tightening can make the anchor ineffective.
Pallet rack anchors are an essential part of the racking system and participate in the support and stability of your racks. From the type of anchor, size, number per baseplate, and torque, none should be neglected when selecting the appropriate anchor for a determined facility. Anchors are a big deal, and their importance should not be underestimated.
All Damotech products are delivered and installed with Hilti screw-type anchors. These anchors offer a high shearing capacity and the possibility of being removed. They are quick and easy to install and are less likely to cause damage to the concrete as they do not have an expanding wedge or sleeve that applies an expansion force.