Results 1 to 7 of 7
  1. #1
    Join Date
    Feb 2009
    Location
    Southern Vancouver Island
    Posts
    4,546

    Default Attic fire separation questions

    A client asked me "what is the fire rating?" of the taped and mudded drywall barrier in his townhouse attic.

    I said it meets the requirements. Is there a better way to answer this question about "fire rating"?

    The drywall covers the roof truss common to the two attics, so that is correct. For roofing, they have open plank strapping, roofing paper and cedar shingles. There is no drywall there, so fire will spread across the roof fairly quickly, I'd say.

    Another question - where seams in the drywall fire separation wall in an attic are not backed by wood framing, are the seams required to be taped and mudded, that is on the exposed backsides of the drywall?

    Inspection Referral SOC
    John Kogel, RHI, BC HI Lic #47455
    www.allsafehome.ca

  2. #2
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    26,244

    Default Re: Attic fire separation questions

    Sounds like you are describing a draftstop wall instead of a firewall.

    Down here ... A 1 or 2 hour firewall would be required.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  3. #3
    Join Date
    Jun 2008
    Location
    Stacy, MN
    Posts
    145

    Default Re: Attic fire separation questions

    Jerry is right, it sounds like a draftstop. A firewall would either extend through the roof with a 30" tall parapet or would turn ad continue under the roof sheathing. Draftstops do not need to be taped if the joints are over framing or are tight. A firewall would need to b tape if that w s a part of its listing approval.


  4. #4
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    26,244

    Default Re: Attic fire separation questions

    Quote Originally Posted by John Kogel View Post
    The drywall covers the roof truss common to the two attics, so that is correct.
    The above and this:
    Another question - where seams in the drywall fire separation wall in an attic are not backed by wood framing, are the seams required to be taped and mudded, that is on the exposed backsides of the drywall?
    Cause me to think there is drywall on one side only. That would be a draftstop wall, not a firewall (a firewall has gypsum board on both sides).

    Also, a firewall would require, as Fred said, ether the firewall going through the roof with a parapet wall above, or the underside of the roof being protected with gypsum board out at least 4 feet each side of the firewall.

    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  5. #5
    Join Date
    Feb 2009
    Location
    Southern Vancouver Island
    Posts
    4,546

    Default Re: Attic fire separation questions

    Thanks Jerry and Fred.

    I was under the impression that the wall is there to slow the spread of a fire, and a draftstop would do that.
    Sometimes in a condo building we will see the concrete block wall extending up through the roof. OK, that will stop a fire.

    John Kogel, RHI, BC HI Lic #47455
    www.allsafehome.ca

  6. #6
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    26,244

    Default Re: Attic fire separation questions

    Quote Originally Posted by John Kogel View Post
    I was under the impression that the wall is there to slow the spread of a fire, and a draftstop would do that.
    Sometimes in a condo building we will see the concrete block wall extending up through the roof. OK, that will stop a fire.
    With a condo, the structure is a single structure, not multiple attached structures like townhouses are.

    With a condo or apartment buildings (down here) a draftstop wall is required in the attic above every two units or 3,000 sf, whichever is less, for 4-stories or less, every dwelling unit otherwise, and must be in line with the separation walls below.

    With townhouses, which are separate but attached structures, they are separated by a firewall of either 1 or 2 hour rating (some variables apply, that is why the two options). With townhouses, the intent is that one of the attached structures can fall down/burn down but the other formerly attached structures will remain standing (for at least the 1 or 2 hours of the separation wall anyway),

    Almost sounds like your structures 'up there' are constructed the opposite? Strange.

    Last edited by Jerry Peck; 06-03-2014 at 05:13 AM. Reason: Removed duplicate "or every dwelling units"
    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  7. #7
    Join Date
    Feb 2009
    Location
    Southern Vancouver Island
    Posts
    4,546

    Default Re: Attic fire separation questions

    Not really opposite but the rules are certainly less stringent for townhouse fire separation. Or were so, because a lot of these buildings were built before the rules were sorted out, i suppose.

    John Kogel, RHI, BC HI Lic #47455
    www.allsafehome.ca

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •