Shims are placed at structural cabinet points to support the slab without creating concentrated stress. Large unsupported gaps can allow movement and cracking. Cabinet adjustment is preferable when the tops are twisted or substantially out of level. Shim material should remain stable and should not compress, rot, or shift.

Key considerations

  • surface flatness
  • structural stability
  • crack resistance
  • localized support
  • stable shim material
  • cabinet correction
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