Results 1 to 9 of 9
  1. #1
    Stephen G Sheldon's Avatar
    Stephen G Sheldon Guest

    Default Is duct insulation considered a combustible

    In a crawl space the furnace vent passes along side and touches an insulated duct vent. Should I call this out or Is this acceptable?

    Similar Threads:
    ***IMPORTANT*** You Need To Register To View Images ***IMPORTANT*** You Need To Register To View Images
    Inspection Referral SOC

  2. #2
    A.D. Miller's Avatar
    A.D. Miller Guest

    Default Re: Is duct insulation considered a combustible

    Quote Originally Posted by Stephen G Sheldon View Post
    In a crawl space the furnace vent passes along side and touches an insulated duct vent. Should I call this out or Is this acceptable?
    SS: Acceptable, though the slightest possibility exists for developing a "hot spot" in the vent at the pooint of contact with the insulation.


  3. #3
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    26,246

    Default Re: Is duct insulation considered a combustible

    Quote Originally Posted by Stephen G Sheldon View Post
    In a crawl space the furnace vent passes along side and touches an insulated duct vent. Should I call this out or Is this acceptable?
    Quote Originally Posted by A.D. Miller View Post
    SS: Acceptable, though the slightest possibility exists for developing a "hot spot" in the vent at the pooint of contact with the insulation.
    Stephen,

    NOT ACCEPTABLE.

    Forget the part about being combustible or not, no insulation is allowed within the stated clearance either.

    Last edited by Jerry Peck; 07-27-2009 at 11:59 AM. Reason: typo Aaron pointed out.
    Jerry Peck, Construction / Litigation Consultant
    Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
    www.AskCodeMan.com

  4. #4
    A.D. Miller's Avatar
    A.D. Miller Guest

    Default Re: Is duct insulation considered a combustible

    Quote Originally Posted by Jerry Peck View Post
    Stephen,

    NOT ACCEPTABLE.

    Forget the part about being combustible or not, not insulation is allowed within the stated clearance either.
    JP: Which part of the insulation in question is combustible at those termperatures?


  5. #5
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    26,246

    Default Re: Is duct insulation considered a combustible

    Quote Originally Posted by A.D. Miller View Post
    JP: Which part of the insulation in question is combustible at those termperatures?
    Aaron,

    Did you not read what I posted and you quoted?

    Quote Originally Posted by Jerry Peck View Post
    Forget the part about being combustible or not, not insulation is allowed within the stated clearance either.


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

  6. #6
    Join Date
    Mar 2007
    Location
    Near Philly, Pa.
    Posts
    1,643

    Exclamation Six issues here

    The duct wrap does not meet ASTM E-136 so therefore it should be treated as "combustible" inspite of our own personal perception of the material.

    The insulation is not only invading in the stated clearance space but is in direct contact. This blocks the flow of cooling air and creates a hot spot.

    The point where the insulation is in contact is obscured from normal inspection. A bad spot could develop there undetected. This is why the codes and stds. do not allow covers or wrapping of vent connectors. B-vent and L-vent, being listed systems with a proven track record are allowed as connectors even though their outer skin prevents direct visualization of the flue lining. You still must maintain the clearance to their outer skin per their listing.

    Practically speaking, all that heat against that insulation may release either formaldehyde or phenol resins, both of which are nasty, stink and carcinogens.

    The 'foil' scrim you see is actually FSK--foil scrim kraft, otherwise known as brown paper wrapped in tin foil. It carries a flame spread of 25 but IS combustible.

    Should not be using single walled vent connector in a crawl space.

    Any more pics?
    Bob

    Last edited by Bob Harper; 07-27-2009 at 12:14 PM.
    Keep the fire in the fireplace.

  7. #7
    A.D. Miller's Avatar
    A.D. Miller Guest

    Default Re: Is duct insulation considered a combustible

    Did you not read what I posted and you quoted?
    JP: I did, but what does this mean?:not insulation is allowed within the stated clearance either


  8. #8
    A.D. Miller's Avatar
    A.D. Miller Guest

    Default Re: Six issues here

    [quote=Bob Harper;93633]The duct wrap does not meet ASTM E-136 so therefore it should be treated as "combustible" inspite of our own personal perception of the material.

    BH: As a fire espert you are certainly aware that anything is combustible with enough heat applied to it.

    The insulation is not only invading in the stated clearance space but is in direct contact. This blocks the flow of cooling air and creates a hot spot.
    BH: That is what I said.

    The point where the insulation is in contact is obscured from normal inspection. A bad spot could delelop there undetected. This is why the codes and stds. do not allow covers or wrapping of vent connectors. B-vent and L-vent, being listed systems with a proven track record are allowed as connectors even though their outer skin prevents direct visualization of the flue lining. You still must maintain the clearance to their outer skin per their listing.
    BH: Good point. Hadn't consdered that.

    Practically speaking, all that heat against that insulation may release either formaldehyde or phenol resins, both of which are nasty, stink and carcinogens.
    BH: Maybe.


  9. #9
    Join Date
    Mar 2007
    Location
    Ormond Beach, Florida
    Posts
    26,246

    Default Re: Is duct insulation considered a combustible

    Quote Originally Posted by A.D. Miller View Post
    JP: I did, but what does this mean?:not insulation is allowed within the stated clearance either
    Typo:

    "not insulation is allowed within the stated clearance either"

    Should be:

    "no insulation is allowed within the stated clearance either"

    Which means that if that is single wall - no insulation is allowed within the 6" minimum clearance.

    For Type B gas vents that clearance is 1" with no insulation allowed within that clearance.

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

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
  •