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Fire caulk on rated walls

Fire caulk on rated walls

New postby CoryBrit on Mon Aug 10, 2015 12:34 pm

I have a question with the International Code Council 2012 building code.

Section 2508.3 states: Edges and ends of gypsum board shall be in moderate contact except in concealed spaces where fire-resistance-rated construction, shear resistance or diaphragm action is not required.
Our inspector is reading this as any gap in the sheetrock larger than 1/8” must be injected with HILTI fire caulk on any rated and load bearing walls.

Section 2508.4 states: Gypsum board fire-resistance-rated assemblies shall have joints and fasteners treated. (it does not say what the joints are to be treated with)

Exception: Joint and fastener treatment need not be provided where any of the following conditions occur:
1. Where the gypsum board is to receive a decorative finish such as wood paneling, battens, acoustical finishes or any similar application that would be equivalent to joint treatment.
2. On single-layer systems where joints occur over wood framing members.
3. Square edge or tongue-and-groove edge gypsum board (V-edge), gypsum backing board or gypsum sheathing.
4. On multilayer systems where the joints of adjacent layers are offset from one to another.
5. Assemblies tested without joint treatment.

My questions are:
Is fire caulking required along all perimeter edges of the lids, first and second layer, on any gaps more than 1/8”?
Is fire caulking required on all rated perimeter walls with gaps larger than 1/8”?
Is fire caulking required on boxes over-zipped on the lid or walls?
If yes on any of the above, will fire tape be sufficient on any of the above mentioned areas?
CoryBrit
 
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Re: Fire caulk on rated walls

New postby Jerry Peck - Codeman on Tue Aug 11, 2015 4:58 pm

Cory,

I am travelling and am trying to get some updated information to answer your question as to the current requirements.

From your description, no, fire caulk is not required as you described - it may be one option, but not a requirement.

Drywall compound may, to my knowledge, be used to achieve the same filling of the joints requirement - that is one of the things I am verifying.

Hopefully, I will have a more complete answer tomorrow.

Jerry
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Re: Fire caulk on rated walls

New postby Jerry Peck - Codeman on Thu Aug 13, 2015 9:49 pm

CoryBrit wrote:My questions are:
Is fire caulking required along all perimeter edges of the lids, first and second layer, on any gaps more than 1/8”?

- See reply below, there should not be any gaps or spaces, so, no, fire caulking would not be required, but if there were some small gaps or spaces, a positive setting joint compound should be able to address the issue ... an have the installers address it the next time by taking more care when they are hanging the gypsum board (I have seen the hangers waste more time, and more board, by not taking the time that they should have at the start).

Is fire caulking required on all rated perimeter walls with gaps larger than 1/8”?

- As stated in my previous reply - No, fire caulking is not "required" for edges (factory edges, typically tapered or square edge) nor for factory or field cut ends which land on framing to meet the fire-resistance rating of a rated design.
- From the 2012 IBC (as you referenced - bold and underlining are mine)
- - 2508.3 Single-ply application.
- - - Edges and ends of gypsum board shall occur on the framing members, except those edges and ends that are perpendicular to the framing members. Edges and ends of gypsum board shall be in moderate contact except in concealed spaces where fire-resistance rated construction, shear resistance or diaphragm action is not required."
- - "shall be in moderate contact" does not provide for a 1/8 inch gap or space between the edges (the long factory edges covered by the finish paper) or ends (field cut or factory cut ends), and the code wording does include both "Edges and ends ".
- - However, nothing requires fire caulking either. If the gap or space is overly wide for a long distance (which will be defined by your local inspector), then the entire space could be packed and filled with a positive setting-time joint compound (so the joint compound stays in place. If there were long areas of overly wide gaps and spaces, I recommend repairing those areas in accordance with GA-225-08 ( https://www.gypsum.org/wp/wp-content/up ... 225-08.pdf ), a few repairs like this and your drywall contractor will pay more attention to how they are installing the gypsum boards so as not to have to make repairs such as shown and described in that document.
- - The key in this discussion with your inspector is to have your inspector provide documentation to support his/her position and for you to have documentation to support your position, and there is no documentation which fully and technically supports either position. There is the code which uses the phrase "Edges and ends of gypsum board shall be in moderate contact" ... while that does not support your position ... it does not support his position either, but does provided credence that 'something' needs to be done to address the gaps and spaces.
- - How tight should the ends be to each other? From National Gypsum Gold Bond Fire-Shield, page 66 in this document: https://www.nationalgypsum.com/resource ... tGuide.pdf , second paragraph under the red heading "Recommendations" - "Gypsum board shall be applied first to ceiling at right angles to framing members, then to walls. Boards of maximum practical length shall be used so that an absolute inimum number of end joints occur. Board edges shall be brought into contact with each other but shall not be forced into place."

- - Now, if you were referring to regular gypsum board and not Type X, then the allowable gap of space would be 1/16 inch, as shown on page 68 under the red heading "Recommendations", then down to A. Board Application, but ... that is not for Type X.

Is fire caulking required on boxes over-zipped on the lid or walls?

- If the wall is a smoke barrier too, then, yes, all openings must be smoke sealed as well as having opening protectives based on the type of boxes used, their listing information, and their limitations - I have a good article on this subject available here: http://jerrypeck.com/IFCN/IFCN.htm top line, either link to 'Electrical Boxes in rated walls' ... many details frequently ignored are addressed.

IF the wall is a fire-resistance rated wall only (and not also a smoke barrier), then this would be applicable:
- From the 2012 IBC: (bold and underlining are mine)
- - 714.3.2 Membrane penetrations.
- - - Membrane penetrations shall comply with Section 714.3.1. Where walls or partitions are required to have a fire-resistance rating, recessed fixtures shall be installed such that the required fire-resistance will not be reduced.
- - - - Exceptions:
- - - - - 1. Membrane penetrations of maximum 2-hour fire-resistance-rated walls and partitions by steel electrical boxes that do not exceed 16 square inches (0.0 103 m2) in area, provided the aggregate area of the openings through the membrane does not exceed 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.1 mm). Such boxes on opposite sides of the wall or partition shall be separated by one of the following:
- - - - - - 1.1. By a horizontal distance of not less than 24 inches (610 mm) where the wall or partition is constructed with individual noncommunicating stud cavities;
- - - - - - 1.2. By a horizontal distance of not less than the depth of the wall cavity where the wall cavity is filled with cellulose loose-fill, rockwool or slag mineral wool insulation;
- - - - - - 1.3. By solid fireblocking in accordance with Section 718.2.1;
- - - - - - 1.4. By protecting both outlet boxes with listed putty pads; or
- - - - - - 1.5. By other listed materials and methods.
- - - - - 2. Membrane penetrations by listed electrical boxes of any material, provided such boxes have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.1 mm) unless listed otherwise. Such boxes on opposite sides of the wall or partition shall be separated by one of the following:
- - - - - - 2.1. By the horizontal distance specified in the listing of the electrical boxes;
- - - - - - 2.2. By solid fireblocking in accordance with Section 718.2.1;
- - - - - - 2.3. By protecting both boxes with listed putty pads; or
- - - - - - 2.4. By other listed materials and methods.
- - - - - 3. Membrane penetrations by electrical boxes of any size or type, which have been listed as part of a wall opening protective material system for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing.
- - - - - 4. Membrane penetrations by boxes other than electrical boxes, provided such penetrating items and the annular space between the wall membrane and the box, are protected by an approved membrane penetration firestop system installed as tested in accordance with ASTM E 814 or UL 1479, with a minimum positive pressure differential of 0.01 inch (2.49 Pa) of water, and shall have an F and T rating of not less than the required fire-resistance rating of the wall penetrated and be installed in accordance with their listing.
- - - - - 5. The annular space created by the penetration of an automatic sprinkler, provided it is covered by a metal escutcheon plate.
- You would need to check the listing of the boxes to make sure that they were not "unless listed otherwise" as stated in "The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.1 mm) unless listed otherwise."
- If the wall is a smoke barrier ... then it has to be sealed anyway.

If yes on any of the above, will fire tape be sufficient on any of the above mentioned areas?

- See the above as there are too many variable to lump into one answer.

Additionally, this is a non-compliant item I find all to frequently - the architect/designer or record may miss it, the drywall contractor seldom even consider it, and the drywall hangers end up putting the Type X and the Type C wherever they happen to install what they picked up - typically, Type C will be required for floor/ceilings and roof/ceiling assemblies:
- TYPE X AND TYPE C: KNOW THE DIFFERENCE
- - http://www.usg.com/content/dam/USG_Mark ... WB2605.pdf

I think I have addressed your questions, if not, please let me know.
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