1. ATTENTION returning members. If you are coming here from the old forum for the first time, you will need to reset you password. However, we had an email problem getting password reset links set out to a lot of the email addresses. That problem is temporarily rectified but IF you still have an issue, email me direct at info@thebuildingcodeforum.com and I will give you a temporary password.
    Dismiss Notice
  2. 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

Cathedral ceiling

Discussion in 'Residential Building Codes' started by MT323, Nov 28, 2017.

  1. MT323

    MT323 New Member

    Joined:
    Nov 28, 2017
    Messages:
    3
    Likes Received:
    0
    Where in the irc can i find information on spanning of the ridge beam in a cathedral ceiling? For example in section R802.3.1 it says only that if ceiling joists are not provided the ridge should be supported by a wall or girder designed in accordance with accepted engineering practice.
     
  2. cda

    cda Sawhorse

    Joined:
    Oct 19, 2009
    Messages:
    12,983
    Likes Received:
    607
    Welcome?

    So is this house in the Republic of Latvia??

    May be a little hard to give a good answer.

    Do you have a web link to the residential code used by the Republic of Latvia???
     
  3. steveray

    steveray Sawhorse

    Joined:
    Nov 25, 2009
    Messages:
    5,329
    Likes Received:
    518
    LVL or engineered lumber company literature....You won't find it in the IRC
     
  4. Pcinspector1

    Pcinspector1 Platinum Member

    Joined:
    Oct 28, 2009
    Messages:
    2,063
    Likes Received:
    127
    The WFCM (Wood Frame Construction Manual) has ridge beam capacity requirements for interior center bearing roof and ceiling, you'll need the snow load to use the table 2.16, engineering is advisable, you'll need fastener information and bearing requirements at the beams ends.
     
  5. mark handler

    mark handler Sawhorse

    Joined:
    Oct 25, 2009
    Messages:
    9,081
    Likes Received:
    354
    Accepted Engineering Practices consist of proven engineering methods, procedures, and practices that provide appropriate, cost-effective, and well-documented solutions to meet requirements and compliance with applicable regulations.
     
    my250r11 and Francis Vineyard like this.
  6. Mark K

    Mark K Platinum Member

    Joined:
    May 12, 2010
    Messages:
    1,241
    Likes Received:
    31
    "accepted engineering practices" is vague.

    I would say that this beam needs to be designed by a registered architect or engineer in accordance with the provisions in the IBC.
     
  7. Pcinspector1

    Pcinspector1 Platinum Member

    Joined:
    Oct 28, 2009
    Messages:
    2,063
    Likes Received:
    127
    Mark, do you have a rubber stamp that sez all of that? :eek: or the one that Mark K posted "accepted engineering practices" is vague.
     
  8. conarb

    conarb Sawhorse

    Joined:
    Oct 22, 2009
    Messages:
    2,882
    Likes Received:
    181
    I've worked in an AHJ that not only requires an engineer's stamp but siesmic loads applied in 4 directions, then wind loads superimposed upon those siesmic loads, we don't have snow or I bet they would require snow loads apllied to those superimposed wind loads. I've had them make me bring my engineer in with the engineering program he used and watched the plan checker SE make my engineer go thhrough the process. At my next meeeting after he made changes they agreeed on she asked me: "Where did you find that guy?"
     
  9. cda

    cda Sawhorse

    Joined:
    Oct 19, 2009
    Messages:
    12,983
    Likes Received:
    607

    Some people you have to spell out all the requirements
     
  10. Mark K

    Mark K Platinum Member

    Joined:
    May 12, 2010
    Messages:
    1,241
    Likes Received:
    31
    Conarb

    Your plan checker who required both wind and seismic at the same time was wrong. Asking the engineer to bring in the program is hard to justify. Where did they find the plan checker?

    The problem here is one where there is no clear solution in the IRC and thus you need to look to the IBC. Also in California the licensing laws would require an engineer or architect to design the beam.
     
    my250r11 likes this.
  11. MT323

    MT323 New Member

    Joined:
    Nov 28, 2017
    Messages:
    3
    Likes Received:
    0
    Once I know the capacity how do I determine the beam's size and spanning by engineering methods? There's also a table on ridge beam spans in the prescriptive part, which for some reason is not present in the irc. Should I better use that?
     
  12. Ty J.

    Ty J. Active Member

    Joined:
    Aug 2, 2017
    Messages:
    40
    Likes Received:
    19
    Non-Prescriptive Construction => Follow IBC => Designed by an Engineer
     
    my250r11 likes this.
  13. conarb

    conarb Sawhorse

    Joined:
    Oct 22, 2009
    Messages:
    2,882
    Likes Received:
    181
    Mark:

    The home was designed using a German engineering program, I asked her if she had it and she said yes, she is a SE. She finally admitted that she didn't have that program but that she had used it in a prior jurisdiction, so she asked that my engineer provide nodal points so she could transfer it to her program, finally she admitted that she couldn't transfer the nodal points and didn't have that program and asked me to bring my engineer in with the program loaded on a laptop so they could go over design forces together. I agreed and stood over them while he animated the program, he was bringing forces from two directions so she sent him back to redo it with forces from 4 directions, once he started animating the seismic forces she then demanded that he superimpose wind loads from all 4 directions, I stood over them and watched the whole procedure. I must say that these computerised animated design programs are impressive to watch, as forces are applied you can watch the frame flex throughout the structure, in this case my customer was educated as a mechanical engineer and had no problem with the added requirements or the additional costs assoicated with complying with them, but not everybody can afford this kind of design, one column to beam change agreed upon ended up costing an additional $44,000, when I told the customer he merely asked if it would make his house stronger? When I said yes he readily agreed to pay the additional amount.
     
  14. Francis Vineyard

    Francis Vineyard Sawhorse

    Joined:
    Jan 1, 2010
    Messages:
    2,729
    Likes Received:
    248
    The following definition from the 2015 Residential Code Essentials is the same found in the (2015) IBC commentary:
    accepted engineering practice – Engineered analysis based on well-established principles of mechanics and conforming to accepted principles, tests, or standards of nationally recognized technical authorities.

    IRC commentary explains one of the reason for accepted engineering practice "it is difficult to accurately and fully present all of the support methods in one set of prescriptive provisions."

    R301.1.3 also provides for an engineered design in accordance with the IBC is permitted (not prohibited) and the AHJ or state law may determine the when a seal is required. Some states may allow manufacturers documentation of their specifications, or the plans signed by the individual (not company) responsible for the design, including the individual's occupation and address.

    http://www.southernpine.com/app/uploads/SS_15-20L.pdf
     
    JBI and Pcinspector1 like this.
  15. cda

    cda Sawhorse

    Joined:
    Oct 19, 2009
    Messages:
    12,983
    Likes Received:
    607


    So is this house in the Republic of Latvia??
     
  16. MT323

    MT323 New Member

    Joined:
    Nov 28, 2017
    Messages:
    3
    Likes Received:
    0
    Yes it is.
    No inspectors will check it, i just need to make sure it is safe.
     
  17. conarb

    conarb Sawhorse

    Joined:
    Oct 22, 2009
    Messages:
    2,882
    Likes Received:
    181
    Be sure to comply with ADA, you may have imbeciles moving in there.
     
    JCraver likes this.
  18. cda

    cda Sawhorse

    Joined:
    Oct 19, 2009
    Messages:
    12,983
    Likes Received:
    607

    Ok send the plane ticket and hotel room

    Will be there
     
  19. JBI

    JBI Sawhorse

    Joined:
    Oct 17, 2009
    Messages:
    2,622
    Likes Received:
    221
    Theoretically, you could use the beam tables in Chapter 5 of the IRC and base it on the applicable loads the roof is likely to have applied to it...
    Kudos for wanting to do the right thing MT323.
     

Share This Page