The most common defects found in wood slabs include slab warping, slab cracking, holes in wood, and soft spots. Slab warping refers to the distortion of the wood slab's shape, often caused by uneven drying or changes in moisture content. Slab cracking occurs when the wood undergoes stress due to moisture changes, resulting in visible cracks. Holes in wood can be caused by insect activity or natural wood defects. Soft spots indicate areas of the slab that have weakened or decayed, compromising the overall integrity.