Can you put a skylight in an Interior Exit Stair roof?

[ETThompson]

I'd always thought no, because of the limitations on openings (1023.4) and penetrations (1023.5) into these enclosures, plus the requirements that the enclosures be Fire Barriers or Horizontal Assemblies (I'd always assumed the latter applies to the roof too). But one of my colleagues got an emphatic verbal indication (written coming) from the ICC that we could in fact include one. Can we? Our client is pushing hard to get one if possible. I have not been able to find anything definitive one way or another on the web...

I'm interested in this in general, but in this specific case it is a 3-story apartment project, we have (2) 1-hour stair enclosures. Type VB Construction, about 12,000 sf, 12 apartments.

 

[RLGA]

The restriction applies to openings through the walls that separate the stairway enclosure from the interior of the building. The roof, if required to be fire rated per the construction type, is permitted openings per Section 712.1.15.

 

[ETThompson]

Thanks for the response. So, even though that section talks about "joints" (with the commentary specifically mentioning expansion and seismic), this would apply to skylights?

Our construction type (VB) does not require the roof to be rated. Would the language in 1023 about minimum ratings for stair enclosures not overrule the VB construction type rules? Or do the rules about minimum hourly ratings and horizontal assemblies just not apply to the roof of the stair, even though it is clearly part of the "enclosure"?

 

[steveray]

The exit enclosure terminates at the roof deck? Not a lid?....It would matter to me.....

 

[RLGA]

Thanks for the response. So, even though that section talks about "joints" (with the commentary specifically mentioning expansion and seismic), this would apply to skylights?

Our construction type (VB) does not require the roof to be rated. Would the language in 1023 about minimum ratings for stair enclosures not overrule the VB construction type rules? Or do the rules about minimum hourly ratings and horizontal assemblies just not apply to the roof of the stair, even though it is clearly part of the "enclosure"?

What code edition are you using? Section 712.1.15 (2018 edition) has nothing to do with joints—were you looking at Section 712.1.5?

Section 1023.4 states, “Openings in interior exit stairways and ramps other than unprotected exterior openings shall be limited to those required for exit access to the enclosure from normally occupied spaces and for egress from the enclosure.”

A skylight is a permitted “unprotected exterior opening.”

 

[ETThompson]

You're right, I misread your response. We are under the 2017 Ohio Building Code based on the 2015 IBC, but the citation is the same.

Thanks this is helpful.