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    MD: Bladensburg (HQ)

    (301) 927-8300

    4700 Annapolis Road, Bladensburg, MD 20710, USA

    Mon-Fri 6:30AM to 4:00PM Saturday 6:30AM to 12:00PM Sunday CLOSED

    Get In Touch with someone at MD: Bladensburg (HQ)
    (301) 927-8300






      Response time within 4 hours

      CMU Fire Rating Chart

      Ted Kelly | September 3, 2015

      Ernest Maier CMU Complying with IBC 2003

      Equivalent Thickness Table 6.0 – Tek Note 7.1

      2005 Supplement

      Fire Resistance Nominal Size ASTM Solid Materials Equivalent Thickness (in)
      ½ Hour 2x8x16

      3x8x16*

      C-145

      C-90

      100%

      79%

      1.9

      1.9

      ¾ Hour 4x8x16

      3x8x16

      C-90

      C-145

      65%

      100%

      2.4

      2.6

      1 Hour 4x8x16

      4x8x12

      4x8x16*

      C-90

      C-90

      C-145

      79%

      73%

      78%

      2.7

      2.7

      2.8

      1 ½ Hours 6x8x16

      8x8x16 Normal Weight

      C-90

      C-90

      54%

      50%

      3.0

      3.8

      2 Hours 2-1/4×3-3/4×8**

      4x8x16

      4x8x12

      8x8x24***

      6x8x16***

      8x8x16 Lightweight***

      C-55

      C-145

      C-145

      C-90

      C-90

      C-90

      100%

      100%

      100%

      52%

      64%

      50%

      3.6

      3.6

      3.6

      3.7

      3.6

      3.8

      3 Hours 8x8x16

      10x8x16

      C-90

      C-90

      63%

      50%

      4.8

      4.8

      4 Hours 8x8x16

      8x8x12

      12x8x12***

      12x8x16

      6x8x16

      8x8x12

      8x8x16

      C-145

      C-145

      C-90

      C-90

      C-145

      C-145

      C-145

      75%

      75%

      55%

      50%

      100%

      100%

      100%

      5.7

      5.7

      5.4

      5.6

      5.6

      7.6

      7.6

       

      * BMS 92 – National Bureau Standard

      ** Concrete Brick

      Primary Aggregates – Expanded Shale and/or Pumice

      Above Blocks Plastered on One Side with 1/2 inch 1:3 Gypsum and Sand Plaster adds 1/2 Hour to Fire Rating

       

      VP of MasonryTed Kelly

      Phone
      Location
      MD: Bladensburg (HQ)
      Languages
      English

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