Sasquatch
Registered User
Hi all,
Long time lurker, first time poster. I'm an architect near Seattle currently permitting a project I'm designing and developing for myself/family. The building is about 30'x60', on a corner of two city streets. It's 3 stories, type VB, and utilizes the single stair exception. The top floor plate is 33' from grade. The stair is exterior and will have 1-hour fire protection where it adjoins units since I have no room for the 10' fire separation. This stair is 1' from the property line on the side of the public sidewalk and street R.O.W. The ground floor has a small B occupancy commercial space (576 SF) and an S2 carport. The upper two floors are all R2. The second floor is two apartments, (725 SF & 810 SF), and the third floor is one apartment at 1586 SF. The roof is intended to be a private roof deck for the upper apartment only, with access only through the upper apartment itself, not accessible to the other tenants. The ground floor is sprinkled with NFPA 13, while the upper two R2 stories are sprinkled with 13R.
I have a few confusing (to me) questions about how to interpret the 2015 IBC given the above:
1. Since putting anything horizontal on the roof deck would make it a 4th floor, that must be avoided, but are we allowed to have a penthouse just big enough to roof over the stair to the roof from the 3rd floor R2 dwelling? IBC 1510.2.3 says "vertical shaft opening" but ours would be open air with a roof over the stair; probably just a single wall or two supporting a roof over the stairs. The stair to the roof is a continuation of the common stair below but walled off from tenants so you have to go through the upper apartment to get roof access.
2. If I don't want to or can't build the penthouse mentioned above, can I install a large access hatch that sticks up no more than 48" from the roof deck surface?
(I know the code has evolved a lot on roof decks in the 2015 IBC, so it's all very vague to me).
3. My common path of egress travel from the furthest point in the 3rd floor unit to the exit door at the bottom of the exterior stair (where two paths can be taken), is just under 125 LF allowed for a single stair building. If I have to measure the exit path from the roof deck I won't make it within 125 LF. Do you know if I have to count the roof deck exit distance since it's not officially a "story" in the IBC? I have no idea. Same question would go for counting the distance from the edge of an exterior balcony to the exit door at grade. If I do then I will have to scrap the roof deck (except for maintenance access?), or find a way to add a second egress stair (maybe impossible). It seems like this is NOT an occupied roof because it's not a story, but I don't really know if that term applies either.
I probably have some other questions, but those are the most pressing right now, if anyone has insight. Thanks in advance if you can help.
Long time lurker, first time poster. I'm an architect near Seattle currently permitting a project I'm designing and developing for myself/family. The building is about 30'x60', on a corner of two city streets. It's 3 stories, type VB, and utilizes the single stair exception. The top floor plate is 33' from grade. The stair is exterior and will have 1-hour fire protection where it adjoins units since I have no room for the 10' fire separation. This stair is 1' from the property line on the side of the public sidewalk and street R.O.W. The ground floor has a small B occupancy commercial space (576 SF) and an S2 carport. The upper two floors are all R2. The second floor is two apartments, (725 SF & 810 SF), and the third floor is one apartment at 1586 SF. The roof is intended to be a private roof deck for the upper apartment only, with access only through the upper apartment itself, not accessible to the other tenants. The ground floor is sprinkled with NFPA 13, while the upper two R2 stories are sprinkled with 13R.
I have a few confusing (to me) questions about how to interpret the 2015 IBC given the above:
1. Since putting anything horizontal on the roof deck would make it a 4th floor, that must be avoided, but are we allowed to have a penthouse just big enough to roof over the stair to the roof from the 3rd floor R2 dwelling? IBC 1510.2.3 says "vertical shaft opening" but ours would be open air with a roof over the stair; probably just a single wall or two supporting a roof over the stairs. The stair to the roof is a continuation of the common stair below but walled off from tenants so you have to go through the upper apartment to get roof access.
2. If I don't want to or can't build the penthouse mentioned above, can I install a large access hatch that sticks up no more than 48" from the roof deck surface?
(I know the code has evolved a lot on roof decks in the 2015 IBC, so it's all very vague to me).
3. My common path of egress travel from the furthest point in the 3rd floor unit to the exit door at the bottom of the exterior stair (where two paths can be taken), is just under 125 LF allowed for a single stair building. If I have to measure the exit path from the roof deck I won't make it within 125 LF. Do you know if I have to count the roof deck exit distance since it's not officially a "story" in the IBC? I have no idea. Same question would go for counting the distance from the edge of an exterior balcony to the exit door at grade. If I do then I will have to scrap the roof deck (except for maintenance access?), or find a way to add a second egress stair (maybe impossible). It seems like this is NOT an occupied roof because it's not a story, but I don't really know if that term applies either.
I probably have some other questions, but those are the most pressing right now, if anyone has insight. Thanks in advance if you can help.