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R507 Deck Attachment too CMU

Discussion in 'Residential Structural Codes' started by jar546, Sep 7, 2019.

  1. jar546

    jar546 *****istrator

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    When I lived up north, I had a raised ranch and built a deck 9' off the ground but still against my CMU foundation. Back then I used staggered lag bolts into lead anchors to attach my ledger board. Behind the ledger board I used large galvanized fender washers to create a 3/8" gap for water to drain. This was in 1997 or so.

    With that being said, how would I legally attach a deck to CMU today under the IRC, specifically both R507.9 for ledger attachment and lateral connection?
     
  2. jar546

    jar546 *****istrator

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    Would R606.11 Anchorage come into play?
    Notice the Note at the bottom of the figure.

    Screen Shot 2019-09-07 at 13.53.28.png
     
  3. ADAguy

    ADAguy Sawhorse

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    self explanatory, no?
     
  4. jar546

    jar546 *****istrator

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    No, not necessarily. Is this detail for interior only? Does it apply to exterior applications?
     
  5. Rick18071

    Rick18071 Sawhorse

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    R507.1 Decks. Wood-framed decks shall be in accordance
    with this section or Section R301 for materials and conditions
    not prescribed herein. Where supported by attachment to an
    exterior wall, decks shall be positively anchored to the primary
    structure and designed for both vertical and lateral
    loads.
    Such attachment shall not be accomplished by the use of
    toenails or nails subject to withdrawal. Where positive connection
    to the primary building structure cannot be verified during
    inspection, decks shall be self-supporting.
    For decks with cantilevered
    framing members connections to exterior walls or
    other framing members shall be designed and constructed to
    resist uplift resulting from the full live load specified in Table
    R301.5 acting on the cantilevered portion of the deck.

    Since the code does not specify how to attach a ledger to a block wall the answer is in bold above or engineered.
     
    jar546 likes this.
  6. jar546

    jar546 *****istrator

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    Agree, since nothing in the deck portion of the IRC points you to R606, how can you use it?
     

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