# Draftstopping Concealed Roof Spaces



## Francis Vineyard (Jan 11, 2017)

In your opinion is it the intent for draftstopping in concealed roof spaces as for attic spaces in reference to exception 3 together and can be used with excepton 1 in R-2?

*2012 IBC*

*ATTIC. *The space between the ceiling beams of the top _story _and the roof rafters.

*718.4 Draftstopping in attics. *In combustible construction, draftstopping shall be installed to subdivide _attic _spaces and concealed roof spaces in the locations prescribed in Sections 718.4.2 and 718.4.3. Ventilation of concealed roof spaces shall be maintained in accordance with Section 1203.2.

*718.4.2 Groups R-1 and R-2. *Draftstopping shall be provided in _attics_, mansards, overhangs or other concealed roof spaces of Group R-2 buildings with three or more _dwelling units _and in all Group R-1 buildings. Draftstopping shall be installed above, and in line with, _sleeping unit _and _dwelling unit _separation walls that do not extend to the underside of the roof sheathing above.

*Exceptions:*

1. Where _corridor _walls provide a _sleeping unit _or _dwelling unit _separation, draftstopping shall only be required above one of the _corridor _walls.

2. Draftstopping is not required in buildings equipped throughout with an _automatic sprinkler system _in accordance with Section 903.3.1.1.

3. In occupancies in Group R-2 that do not exceed four _stories above grade plane_, the _attic _space shall be subdivided by _draftstops _into areas not exceeding 3,000 sf. or above every two _dwelling units_, whichever is smaller.

4. (intentionally not provided)

*718.4.3 Other groups. *Draftstopping shall be installed in _attics _and concealed roof spaces, such that any horizontal area does not exceed 3,000 square feet (279 m2).

(Exception intenionally not provided)


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## north star (Jan 11, 2017)

@ = @


Francis,

Not sure of your question.......See if this is what
you are asking.

In Section 718.4.2, you want to know if Exception
# 1  &  Exception # 3 can be combined to require
draftstopping to: a maximum of 3,000 sq. ft. * and*
above one corridor wall,  ..in the attic spaces and
in concealed roof spaces,  versus one of the Exceptions
or the other ?

Thanks !


*@ = @*


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## Francis Vineyard (Jan 11, 2017)

Can you take exception 3 for flat roofs?


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## JBI (Jan 11, 2017)

Is there an 'attic' below the flat roof?


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## Francis Vineyard (Jan 11, 2017)

Roof/ceilng trusses!


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## tmurray (Jan 11, 2017)

I would consider any space between the top-most ceiling and the roof to be an attic regardless of the slope of roof or the actual space between them, provided there is an interstitial space between the two components..


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## cda (Jan 11, 2017)

Might depend on how built??

Possibly if very flat, no place to put draft stops??


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## steveray (Jan 11, 2017)

"or other concealed roof spaces of Group R-2 buildings"


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## Francis Vineyard (Jan 11, 2017)

steveray said:


> "or other concealed roof spaces of Group R-2 buildings"



Exception 3 only mentions attic unlike the other sections.

Would you define concealed roof spaces as "ceilngs without attic space" and cannot use Exception 3; applicable to attic space only?


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## steveray (Jan 11, 2017)

I would say that you get the 2 unit exception if that is what you are asking...


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## Paul Sweet (Jan 11, 2017)

Draftstopping should be provided between units no matter what the code says.  There's a lot of kindling wood in trussed attics (or flat roofs), and we have had several fires in sprinklered apartments with unsprinklered attics get into the attic and destroy the entire building.  Amazingly these fires haven't killed anybody - yet.


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## JBI (Jan 11, 2017)

Attic is a defined term... The space between the ceiling beams of the top story and the roof rafters. 
I'm not sure the spaces between web members of roof trusses qualify. Draftstop above corridors, between units, and call it a day.


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## JBI (Jan 11, 2017)

Paul Sweet said:


> we have had several fires in sprinklered apartments with unsprinklered attics get into the attic and destroy the entire building



The exception is for fully sprinklered per 903.3.1.1, so a full NFPA 13 system would be required to meet the exception. A 13R won't do.


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## Francis Vineyard (Jan 12, 2017)

Steveray appreciate your straight forward answers in this forum.  Draftstopping shown in red in the drawing: 5A, 13R.


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## steveray (Jan 12, 2017)

Thanks Francis! You too!....I typically don't have time for some of the great lengthy answers I see here, but I will throw my 2 cents in when I can. Losing the good cut and pasteability of publicecodes has hurt a bit too...


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## north star (Jan 12, 2017)

*% = % = %*


***steveray***,

Have you tried using a Snipping Tool from your computer' Desktop ?
I have had "some" success in cutting & pasting from The Cow' website,
and their Codes.


*% = % = %*


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## steveray (Jan 12, 2017)

NS...I think it worked for me once, but I am so busy right now I don't have time to beat it (a new process) through my head


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## Paul Sweet (Jan 13, 2017)

OT, but 1/8" per foot isn't adequate roof slope.


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