Thread: Fire wall in a 1984 Condo/Townhouse

Inspected this 1984 yr old condo today and found that the 5/8 drywall attached underneath the roof trusses had fallen down. Was the a code requirement? I'm assuming it was, because why else would it be there for. Correct

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Yes, the roof sheathing is/was required to be protected for a minimum of 4 feet from the wall.

There are some exceptions, such as a parapet wall to, and through, the roof sheathing minimum 18" high above the roof (obviously, the parapet wall option was not used, thus the underside of the roof sheathing was protected instead).

It usually falls down during or after a re-roof.

Originally Posted by Sam Morris

Inspected this 1984 yr old condo today and found that the 5/8 drywall attached underneath the roof trusses had fallen down. Was the a code requirement? I'm assuming it was, because why else would it be there for. Correct

"I'm assuming it was, because why else would it be there".........Remember, codes are minimum standards. It's okay to make it stronger, safer. A fair amount of contractors go above and beyond.
Unfortunately a lot of firewalls are installed by "workers" who have no experience drywalling, type of fasteners, location of fasteners, quantity. If it's attached to wood, it's gonna move. 6 P's

Shouldn't the drywall be attached to the underside of the roof deck not the underside of the top truss chord?

As has been stated, the sheetrock is a substitution for a 30" parapet wall either at a property line wall or an "area separation" wall. In 1984 the requirement was (under the 1982 UBC) 5'-0" on each side of the wall. This is an incorrect installation however, as the sheetrock is supposed to be on the bottom chord for a truss as it is a complete structural unit. If the bottom chord burns and collapses the top chord will also collapse, so it is pointless to put it on the bottom of the top chord. Building codes are not always well understood or properly administered.

Originally Posted by Thom Huggett

As has been stated, the sheetrock is a substitution for a 30" parapet wall either at a property line wall or an "area separation" wall. In 1984 the requirement was (under the 1982 UBC) 5'-0" on each side of the wall. This is an incorrect installation however, as the sheetrock is supposed to be on the bottom chord for a truss as it is a complete structural unit. If the bottom chord burns and collapses the top chord will also collapse, so it is pointless to put it on the bottom of the top chord. Building codes are not always well understood or properly administered.

So are you saying that the Sheetrock should sit on top of the insulation ?

Standard at the time SE was four feet in. The gyp underside should have been stopped & blocked and properly nailed. It was there to protect the underside of the non-FRT plywood roof decking for four feet in (3rd truss in) for the alternative one-hour separation. It has collapsed - it is not presently where initially intended to have been installed.

Failed likely due to failure to garner approval and execute under ceiling a separated soffit/box for the present and non-compliant location (w/in 4' of common wall/separation wall in truss attic under common roof deck) vinyl/wire (wrong material) exaust fan duct. Should be min. gauge metal and framed and separated with independant box w/ 2-ply 5/8" gyp taped & mudded.

No systems, or mechanicals allowed in the shared roof superstructure except encased in metal & puttied electrical in common separation wall & within 4' of same in roof superstructure.Rigid metal duct only 4' away from separation wall. Scuttle also must be at least 4' inside of same.

At the time the HUD/VA requirement started to allow for 4' out FRT in lieu, FRT ply didn't "fare" well in open unconditioned (HOT) truss attics with open eaves. Suspect decking may have also been (partially) replaced, roofer's or home-owner's attempt to retrofit perhaps; should be underside, all sides of top chord wrapped and blocked for approved at the time alternative assembly. The ceiling below must be continuous blocked & stopped membrane of 5/8" gyp under the bottom chord. At the time spun fiberglass or mineral wool was the insulation (approved, tested assembly) standard.

Originally Posted by H.G. Watson, Sr.

Standard at the time SE was four feet in. The gyp underside should have been stopped & blocked and properly nailed. It was there to protect the underside of the non-FRT plywood roof decking for four feet in (3rd truss in) for the alternative one-hour separation. It has collapsed - it is not presently where initially intended to have been installed.

Failed likely due to failure to garner approval and execute under ceiling a separated soffit/box for the present and non-compliant location (w/in 4' of common wall/separation wall in truss attic under common roof deck) vinyl/wire (wrong material) exaust fan duct. Should be min. gauge metal and framed and separated with independant box w/ 2-ply 5/8" gyp taped & mudded.

No systems, or mechanicals allowed in the shared roof superstructure except encased in metal & puttied electrical in common separation wall & within 4' of same in roof superstructure.Rigid metal duct only 4' away from separation wall. Scuttle also must be at least 4' inside of same.

At the time the HUD/VA requirement started to allow for 4' out FRT in lieu, FRT ply didn't "fare" well in open unconditioned (HOT) truss attics with open eaves. Suspect decking may have also been (partially) replaced, roofer's or home-owner's attempt to retrofit perhaps; should be underside, all sides of top chord wrapped and blocked for approved at the time alternative assembly. The ceiling below must be continuous blocked & stopped membrane of 5/8" gyp under the bottom chord. At the time spun fiberglass or mineral wool was the insulation (approved, tested assembly) standard.

Thank you H.G., that is my understanding of the placement. If I read Thom's post right, he stated it was not placed properly (the Sheetrock is supposed to be on the bottom chord for a truss). I saw the pictures and my observation was that it was properly located but not properly installed.

Originally Posted by H.G. Watson, Sr.

No systems, or mechanicals allowed in the shared roof superstructure except encased in metal & puttied electrical in common separation wall & within 4' of same in roof superstructure.Rigid metal duct only 4' away from separation wall. Scuttle also must be at least 4' inside of same.

No penetrations 'through the roof' within that 4 foot protected distance (which typically went out beyond 4 feet to land on the next truss out past the 4 foot minimum distance).

Penetrations through the ceiling are different, and are.were allowed. There was no requirement for duct work in the area shown in the photo to be metal as that was not "shared roof superstructure", that is a divided attic, one side is over one townhouse and the other side of the attic is over the adjacent townhouse (the wall should be a continuation of the wall separating the two townhouses, thus there is no "shared superstructure", there are two attics).

The separation wall should continue from the foundation up to the roof, and through the roof with a minimum 18 inch high parapet wall; unless the option to protect the roof sheathing to 4 feet to each of the separation wall is taken, in which case no parapet wall is required above the roof.

Originally Posted by Sam Morris

Inspected this 1984 yr old condo today and found that the 5/8 drywall attached underneath the roof trusses had fallen down. Was the a code requirement? I'm assuming it was, because why else would it be there for. Correct

Whoa ... I just noticed that *WE* *ALL* (which includes me ) were on the wrong page.

Originally Posted by Sam Morris

Inspected this 1984 yr old condo ...

"condo"

Changes EVERYTHING we have stated above.

There is no requirement for a "condo" building to have a firewall to the underside of the roof as a "condo" building is "one structure", which means there is no need to protect that from the 'other parts of the same structure', there is, however, a need to "draftstop" the attic at intervals. Typically, those draftstop intervals were every two units with the draftstops aligned with the walls of the condos below the draftstopped areas.

Makes a BIG difference if the structure is a "condo" building or if it is a "townhouse" building - that needs to be clarified, but until that is clarified, the original post *did say* "condo".

The white vinyl exhaust vent is NOT allowed within 4' of the separation wall within the truss attic. Nothing other than metal plumbing and metal encased electrical puttied and sealed is allowed within that 4' clearance area within the fire separation assembly truss chord attic. Was NOT permitted THEN - it is a prescribed assembly and prescribed fire separation alterntive for 1-hour separation.

The roof deck surface and roof are SHARED/common to the COMMON 1-hr wall.

The title of the post is "Fire wall in a 1984 Condo/Townhouse". The row type common wall construction has already been discussed and photographed.

The codes discussed this type of construction. It was NOT addressed OR covered by the 1 & 2 family codes.

Originally Posted by H.G. Watson, Sr.

The white vinyl exhaust vent ...

What "white vinyl exhaust vent"? Are you looking at the same two photos in the original post that I am? Am I just not seeing them, or are you seeing something there which is not there?

... is NOT allowed within 4' of the separation wall within the truss attic.

You are correct ONLY IF you are referring to penetrations through the roof. You not correct if you are referring to penetrations through the ceiling. Additionally, you are not correct as that is a "condo" building and is thus "one structure" and a firewall is not required there - a draftstopping wall MAY be required there, but then the roof would not require any protection on either side of the wall, and ... the original poster stated it was a "condo" - WHICH I pointed out in my previous post.

Nothing other than metal plumbing and metal encased electrical puttied and sealed is allowed within that 4' clearance area within the fire separation assembly truss chord attic.

Again, you would be correct IF you were referring to penetrations through the roof decking ... but the IF does not apply as that is a "condo" (as stated by the original poster in the original post, and he has not yet come back and stated that it was not a condo).

The title ...

THE TITLE ...

... of the post is "Fire wall in a 1984 Condo/Townhouse".

... BUT THE POST ITSELF ... stated it was a "condo".

AS I STATED IN A PREVIOUS POST - IN CASE YOU DID NOT BOTHER TO READ IT ...

Originally Posted by Jerry Peck

Makes a BIG difference if the structure is a "condo" building or if it is a "townhouse" building - that needs to be clarified, but until that is clarified, the original post *did say* "condo".

As such ... until the original poster clarifies it to NOT BE a "condo", your arguments are not applicable.

And IF the original poster does clarify that to NOT BE a "condo", you arguments are simply incorrect.

Watson, take a deep breath, hold it ... hold it ... hold it ... now breathe out slowly ... now relax until the original poster clarifies what type of structure it was - the type of structure MAKES ALL THE DIFFERENCE in what is applicable ... THEN ... we can address your incorrect information, but as it is right now your incorrect information is simply not applicable.

Originally Posted by Jerry Peck

What "white vinyl exhaust vent"? Are you looking at the same two photos in the original post that I am? Am I just not seeing them, or are you seeing something there which is not there?
...........
Watson, take a deep breath, hold it ... hold it ... hold it ... now breathe out slowly ... now relax until the original poster clarifies what type of structure it was - the type of structure MAKES ALL THE DIFFERENCE in what is applicable ... THEN ... we can address your incorrect information, but as it is right now your incorrect information is simply not applicable.

Jerry, but lighten up... It's Christmas Eve. What is the expression about "fish in a barrel?" In the holiday spirit give the poor guy a break. Shuffle up to the Wassail bowel and have a drink! But if you like, you may continue your nailing in late March.

Originally Posted by Terry Silva

So are you saying that the Sheetrock should sit on top of the insulation ?

No, the sheetrock would be on the bottom of the bottom chord to protect the trusses from a fire in the unit.

And by the way, the distance was 5 feet under the 1982 Uniform Building Code. I don't know what the Standard Building Code or National Building Code required. In 1984 I was just learning the ropes as a Plan Check Engineer in Fresno, and I remember thinking that 5' was an odd dimension since trusses are always at 24" oc.

Here is an article which documents the UBC requirements for an area separation wall at that time: http://www.cement.org/codes/pdf/FPPR%20No16U.pdf

Originally Posted by Jerry Peck

Whoa ... I just noticed that *WE* *ALL* (which includes me ) were on the wrong page.



"condo"

Changes EVERYTHING we have stated above.

There is no requirement for a "condo" building to have a firewall to the underside of the roof as a "condo" building is "one structure", which means there is no need to protect that from the 'other parts of the same structure', there is, however, a need to "draftstop" the attic at intervals. Typically, those draftstop intervals were every two units with the draftstops aligned with the walls of the condos below the draftstopped areas.

Makes a BIG difference if the structure is a "condo" building or if it is a "townhouse" building - that needs to be clarified, but until that is clarified, the original post *did say* "condo".

As I stated in my other post, I am only familiar with the UBC in effect at the time, so that may be the reason for the different distances given above.

In the 1980's we were seeing a lot of condos and PUDs (planned unit development) in California. We defined condos as individual ownership from paint to paint, whereas a pud there was individual ownership of building, subject to the HOA.

Walls like this in a condo (or apartment for that matter) were usually due to the presence of a 2-hour fire rated "area separation wall" (roughly a "fire wall" in the IBC) which required a 30" parapet wall. In the pud's there was an actual property line between the units which, with some exceptions, also required a parapet. The "wrap-back" as we called it was a substitution for the parapet, and in the UBC was required to be 5'-0" on each side of the wall. The following article was the standard that plan checkers and architects refered to in their building code analysis.

http://www.cement.org/codes/pdf/FPPR%20No16U.pdf

All that to say that the building could be a condo, apartment or townhome under the UBC.