top, forming a pyramid shape, or the same width from top to bottom. The 1-to-3-rule— when the base is three times wider than the height of the stack— is good to follow.
Avoid creating gaps or voids between materials when creating a cribbing stack. This may contribute to instability, peak loading of individual cribbing members and material or ground failure.
If multiple layers of materials are required, always ensure adequate friction between each layer. Ensuring the cribbing stack is at a right angle will minimize lateral movement. However, when needed, one way to add friction is to add neoprene between the layers to reduce unplanned movement during operations.
Before use always inspect the materials to ensure they are in good condition. These materials must be viewed and evaluated as critical supporting materials. Uniform hardwood timbers in excellent condition or synthetic pads or blocks are ideal options. Because stacking increases risk, it is best to consider products manufactured for this specific purpose. Cribbing blocks with an interlocking surface or interlocking mechanism are typically the best options, as they add mechanical sliding resistance.
For instance, DICA’ s ProStack Pyramid Lock and Slot Lock products are designed to lock together to resist sliding. Both products can interlock with themselves and with other supporting materials. Some SafetyTech outrigger pads are specially designed for this purpose.
Utility work demands precision, especially when equipment is operated on uneven or sloped ground. By incorporating the right cribbing strategies, choosing engineered support solutions and understanding the limits and capabilities of your equipment, crews can prevent instability before it starts. Safety starts with proper training and attention to ground conditions.
Kris Koberg is the President and CEO of DICA, a manufacturer and distributor of supporting materials, ground protection, site access mats and associated products.
14 • 515-955-1600 • October 2025