solid masonry unit



  • A masonry unit whose minimum net cross-sectional area parallel to its bearing surface is 75% or more of its gross cross-sectional area.
  • A masonry unit having holes less than 3/4" (2 cm) wide or less than 0.75 sq in (5 sq cm) passing through, or having frogs that do not exceed 20% of its volume. In either type, up to three handling holes, not exceeding 5 sq in (32.5 sq cm) each, are allowed. The total area of all through holes may not exceed 25% of the gross area.