×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Wood-framed parapet wall with 1:1 Brace on Roof

Wood-framed parapet wall with 1:1 Brace on Roof

Wood-framed parapet wall with 1:1 Brace on Roof

(OP)
I am planning to design a 4-story wood-framed structure with a nominal 3'-6" parapet wall. If the wood bracing with sheathing displaces a triangular area of the roof about 3 feet wide by 3 feet tall, how should I approach the snow drift loads? The ASCE 7-05 ground snow is 30 psf.

Common sense says there will be no drift at the top of the brace since there is only about a 6" vertical projection above it. Take a look at the attached sketch.

RE: Wood-framed parapet wall with 1:1 Brace on Roof

(OP)
My building is in the mountains of Virginia. I know many states make amendments to the IBC and there may be some that address my parapet condition or something similar.

Has anyone taken a look at this problem before?

RE: Wood-framed parapet wall with 1:1 Brace on Roof

I can't find any guidance on this myself with a cursory glance - will have to look harder.

That being said though, I think it is reasonable to assume that it is safe to subtract the snow load in the space taken up by the 1:1 sloped brace. I would still apply the remainder of the snow load as if the 1:1 braced wall was not there.

Mike McCann
MMC Engineering

RE: Wood-framed parapet wall with 1:1 Brace on Roof

Your sketch looks like a conservative approach to me.

Start the drift layout at the back of the parapet but where the height difference between top of parapet and top of structure (roof or cricket or whatever) is less than your base height, no drift would be added.

RE: Wood-framed parapet wall with 1:1 Brace on Roof

Just go with any conservative approach. If you are having design problems with it. You should go and upsize the members/designs anyway. IMHO The extra loads should not be a problem.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources