Garage separation

[Sifu]

I have several folks wanting to spearate a garage area from the rooms above with a rated dropped ceiling assembly. I don't have worries about the equivalent rating to 5/8" type X. I do have some concerns about the gas tight properties which would seal off potential harmful fumes. Does anyone know if any of the drop in systems carry a UL listing for this type of application? Trying to be proactive, in other words cover this base before it gets to me.

 

[Bama dav]

Sifu, there are lots of tested assembly's For drop ceilings. Just make sure that they match the construction.table 302.6 says 5/8 or equivalent so it would be your call.If you have an architect on the job have him/her provide you with a tested assembly.

 

[north star]

$ = $

From the `06 Edition of the IRC, Section R309.1.2 - Other penetrations.

"Penetrations through the separation required in Section R309.2 shall be

protected by filling the opening around the penetrating item with

approved material to resist the free passage of flame and products of

combustion."



$ = $

 

[Builder Bob]

Drop Ceilings are not an air barrier- The IECC does not give credit to this system as it does not create an air barrier -

http://resourcecenter.pnl.gov/cocoon/morf/ResourceCenter/article/1469

Neither of these installations is allowed by the commercial provisions of the 2009 IECC or ASHRAE 90.1 because they do not include an approved air barrier to prevent air movement from the conditioned space through the insulation to the unconditioned space. This technique allows the insulation to be easily disturbed.

Therefore, IMHO, it should not be allowed as CO gas has similar properties as normal atmospheric air and would be allowed to mitigate thru the ACT system into habitable areas....

 

[Sifu]

Told the builder to find a listed assembly. I was just asking to see if anyone knew of one. I have not seen one but that doesn't mean much. If he can't find one He has asked about a 1 hour rated ceiling constructed of gypsum drop-in panels with each one caulked in place and all other penetrations caulked. Sounds reasonable to me but still looking for input.

 

[Francis Vineyard]

Bob drop ceilings of themselves are not an air barrier, however as the article invites along with the code requirement the floor insulation shall "be installed to maintain permanent contact with the underside of the subfloor decking" and an air barrier (house wrap or equivalent) encapsulate the insulation.

Furthermore required fire blocking "to cut off all concealed draft openings to form an effective fire barrier at all interconnections between concealed vertical and horizontal spaces such as drop ceilings."

Sifu I have not found a drop ceiling assembly that is equivalent to 5/8ths Gypsum Type X, except where it uses proprietary Type X with wood floor ceiling joist.

Search "WH TSC/FCA 45 - 04 UL-L529"

As a reminder the required fire separation is 5/8" gypsum Type X or equivalent; not a 1 hour fire resistance assembly.

Francis

 

[KZQuixote]

"...however as the article invites along with the code requirement the floor insulation shall "be installed to maintain permanent contact with the underside of the subfloor decking" and an air barrier (house wrap or equivalent) encapsulate the insulation."Francis

Hi Francis,

While "wind washing" is mentioned in the article, the pressure boundary that prevents the flow of air through the insulation, is located on the warm side of the insulation. I know that encapsulating the insulation is a best practice but I don't see that it's a code requirement.

Bill

 

[Francis Vineyard]

Hi Francis,While "wind washing" is mentioned in the article, the pressure boundary that prevents the flow of air through the insulation, is located on the warm side of the insulation. I know that encapsulating the insulation is a best practice but I don't see that it's a code requirement.

Bill

Thanks for clarifying; I always get myself into trouble trying to explain my own words unless I lift from the code: "All joints and seams shall be caulked, gasketed, weatherstripped or otherwise sealed with an air barrier material, suitable film or solid material."

Francis

 

[KZQuixote]

Hi Francis,

Best Practice in the insulation business is for every given batt of insulation to be covered with something on six surfaces. For instance if I build a pony wall to divide an attic space from a conditioned space I must provide a pressure boundary that prevents the flow of air through the insulation. This pressure boundary must go on the inside (warm side) of the insulation, it could be the drywall. However, best practice in the insulation industry would also require me to cover the attic side with and air barrier material to prevent wind washing of the back side. I do not believe that the energy code requires that the back side be so protected.

Am I missing something? Does the code require the back (attic) side be covered?

TIA

Bill

 

[Francis Vineyard]

Bill,

No you are not missing something with the unconditioned side of the attic insulation. I missed the point of your question with the topics change from the garage to the attic area.

In my opinion the habitable attic configuration you described the code does not require the insulation exposed to the attic ventilation to be sealed. From the questions contractors have asked me and from online research some jurisdictions however do require that knee wall and the attic floor to be enclosed in an air barrier; the beats all requirement 12. Other sources of infiltration.

Going back to the ceiling/floor assembly between the dwelling/garage points of inspection does make the insulation "encapsulated" in an air barrier.

TABLE N1102.4.2 AIR BARRIER AND INSULATION INSPECTION

Ceiling/attic

Air barrier in any dropped ceiling/soffit is substantially aligned with insulation and any gaps are sealed

Floors (including above garage and cantilevered floors)

Insulation is installed to maintain permanent contact with underside of subfloor decking. Air barrier is installed at any exposed edge of floor.

Francis

 

[Francis Vineyard]

Bill,

Could you interpret from the definition below and the visual inspection list that both the exterior and interior side of the thermal envelope shall be air sealed including all horizontal to vertical cavities congruent with fireblocking (draftstopping), the exception would be by way of the blower test?

BUILDING THERMAL ENVELOPE. The basement walls, exterior walls, floor, roof and any other building element that enclose conditioned spaces.

A quick list (hyperlinks) of some states that require the knee wall to be sealed:

Coconino County AZ

Georgia

Idaho



Pennsylvania (Webinar)



Francis