Roof openings near FIREWALL

[Examiner]

Construction Type II-B w/ fully automatic fire suppression system. Non-combustile roof construction

Occupancy Use: Educational.

Fire Walls required: 2-hour rated

SECTION 705

FIRE WALLS

IBC 705.6 Exception #3. Walls shall be permitted to terminate at the underside of noncombustible roof sheathing, deck, or slabs where both buildings are provided with not less than a Class B roof covering. Openings in the roof shall not be located within 4 feet (1220 mm) of the fire wall.

Questions:

Is the Code addressing openings in the roof as a “real opening” that is not covered or used by a skylight, HVAC item, roof drains/vents or Expansion Joint? A real opening would be one that would require guardrails or parapet where you can see from the roof down to the floor below and not closed up with skylights HVAC items, roof drain or Expansion Joint.

There are HVAC RTU’s, Exhaust Fans and roof drains/vents within 4-feet of the firewall. Would any of these items be considered roof openings?

One firewall has a continuous roof / building expansion joint abutting the firewall and running perpendicular to the firewall on one side. Would the Expansion Joint be considered a roof opening? Can the roof expansion joint, if it is a roof opening, have a 2-hour Expansion Joint fire stop system and be in compliance?

Another firewall, not extending above the roof, has a roof expansion joint between the firewall and another non-combustible wall. Both walls do not extend above the roof but stop at the roof deck. The expansion joint runs along each face of the two walls. What would be your take on this expansion joint?

 

[Coug Dad]

Re: Roof openings near FIREWALL

I believe the code does not permit any openings, including HVAC or vents within the first four feet if this exception is used.

 

[JBI]

Re: Roof openings near FIREWALL

What Coug Dad said and, no the expansion joint is not an opening IMHO.

 

Re: Roof openings near FIREWALL

Why not seal the expansion joint with the proper in-tumescent material? The correct material depends on the width of the gap and cycles it can withstand.

 

[Examiner]

Re: Roof openings near FIREWALL

JD, the expansion joint is not just a roof membrane expansion joint but a building expansion joint with the opening for the joint through the roof deck. From the floor below the roof, you would see daylight if the expansion joint did not have a cover. Is this not a roof opening?

I had thought of the approved fire rated joint system but is it allowed?. The Code did say no roof openings within 4-feet of the firewall it did not say that protected openings were allowed, thus the reason for the inquiry.

 

[JBI]

Re: Roof openings near FIREWALL

Ex - Not IMHO (in my humble opinion). If it were, then one could not use that particular roof design on ANY building that had a 'fire wall'. Sounds a bit restrictive to me. When I think of 'openings' I don't think of expansion joints; I think of skylights, access doors/scuttles, ducts, vents, etc. Things that create a 'hole' in the roof. But that is just my opinion and as we all know, opinions will vary. Wouldn't be the first time I was in the minority (or the 'Lone Ranger' )

As far as the 'approved fire rated joint system', does the approval INCLUDE this particular application? The answer is in the listing information...

Once firestopped, would you still consider it an 'opening'?