1. Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by clicking here: Upgrades
    Dismiss Notice

Joist solid blocking

Discussion in 'Residential Building Codes' started by alaskajoe, Mar 3, 2020.

  1. alaskajoe

    alaskajoe Registered User

    Joined:
    May 22, 2019
    Messages:
    35
    Likes Received:
    5
    Floor joist (2 x 10) spanning 14 feet. Do you need solid blocking anywhere but the ends?
     
  2. Rick18071

    Rick18071 Sawhorse

    Joined:
    Nov 28, 2009
    Messages:
    2,378
    Likes Received:
    313
  3. fatboy

    fatboy Administrator

    Joined:
    Oct 17, 2009
    Messages:
    5,926
    Likes Received:
    650
    Agreed, not required.
     
  4. Pcinspector1

    Pcinspector1 Platinum Member

    Joined:
    Oct 28, 2009
    Messages:
    3,241
    Likes Received:
    465
    Assuming there is no cantilever I agree with my comrades.
     
  5. e hilton

    e hilton Bronze Member

    Joined:
    Jul 2, 2014
    Messages:
    873
    Likes Received:
    193
    If it was 2x12 it would require one row of blocking for that span ... right?
     
  6. Inspector Gift

    Inspector Gift Sawhorse - Made in USA

    Joined:
    Oct 17, 2009
    Messages:
    289
    Likes Received:
    82
    Blocking is Required for Joists greater than 2x12 at intervals not exceeding 8 feet. (See R502.7.1 Bridging)
     
    Ty J. and Pcinspector1 like this.
  7. ADAguy

    ADAguy Registered User

    Joined:
    Sep 11, 2013
    Messages:
    4,390
    Likes Received:
    419
    spot on, consider that without blocking there will be more bounce. Good practice to block, it may also depend on the subfloor material.
     
  8. Ty J.

    Ty J. Sawhorse

    Joined:
    Aug 2, 2017
    Messages:
    984
    Likes Received:
    370
    I concur with most of the above comments, blocking is only required at the ends.

    However, bridging is required at 8-ft when using joists larger than 2x12. Most often completed (at least here) via a strap such as Simpson's LTP.

    Inspector Gift has the right reference, but note that it specifies larger than 2x12.

    R502.7.1 Bridging

    Joists exceeding a nominal 2 inches by 12 inches (51 mm by 305 mm) shall be supported laterally by solid blocking, diagonal bridging (wood or metal), or a continuous 1 inch by 3 inch (25.4 mm by 76 mm) strip nailed across the bottom of joists perpendicular to joists at intervals not exceeding 8 feet (2438 mm).

    Exception: Trusses, structural composite lumber, structural glued-laminated members and I-joists shall be supported laterally as required by the manufacturer's recommendations.

    [​IMG]
     
    #8 Ty J., Mar 3, 2020
    Last edited: Mar 3, 2020
    Inspector Gift likes this.
  9. alaskajoe

    alaskajoe Registered User

    Joined:
    May 22, 2019
    Messages:
    35
    Likes Received:
    5
    That is how I see it Thanks all. I still encourage people with larger spans to block. As was said Best Practice and not minimum standard. Makes for less bounce to the ounce.
     
  10. e hilton

    e hilton Bronze Member

    Joined:
    Jul 2, 2014
    Messages:
    873
    Likes Received:
    193
    I’m seeing some interesting language in the code that has me a little confused.

    2015 IBC 2308.4.6 (slightly paraphrased) Framing with depth to thickness ratio not less than 5 to 1 shall have one edge held in line for the entire span. (So framing of 2x8 doesn’t require restraint?) Where the ratio exceeds 6 to 1 there shall be bridging, unless both edges are held in line.

    It says “for the entire span” so does that mean that ceiling strapping at say 16” oc does not qualify? And I assume this is for sawn lumber only, TJI’s would have to be installed per mfgr requirements.
     

Share This Page