Unenclosed bridge between two structures as part of exit access?

[nealderidder]

I'm looking at two R-2 structures (approx 20' apart) with an uncovered unenclosed bridge between them serving as exit access to a second exit. There is only one stair in each "structure" and I'm connecting them to use the stair in the "other" structure as my second exit. Get it?

Assuming I'm OK on travel distance, floor area and everything else. Is there a problem with the open-air bridge being a part of the exit access? It just seems wrong to me to exit a structure, cross a bridge and re-enter a structure to reach an exit but I can't find anything restricting me from doing so...

Thanks,

Neal

 

[mark handler]

Neal

Is this being built under the IRC or the IBC?

If under the IBC refer to chapter 31

3104.5 Fire barriers between pedestrian walkways and buildings.

 

[nealderidder]

Sorry, 2006 IBC.

I don't see anything in 3104.5 that disallows the bridges as an exit access component. My buildings are more than 10' apart, my exterior walls aren't required to be rated and the "bridges" will be at least 50% open... so the bridges can be part of the exit access and don't even require rated construction of any kind. Still just seems wrong...

 

[mark handler]

Neal

I didn't know from your OP that you wanted to disallow the bridge. I was asking which code? And if it is IBC read chapter 31

 

[nealderidder]

Mark - I'm not trying to disallow anything, its my design! I just have this little voice in the back of my head telling me I'm doing something wrong. Maybe its the idea that once you've established a level of fire protection you can't reduce it until you get to an exit. In this case I'll be going from rated corridor to exterior unrated bridge back to rated corridor. I may be worrying about nothing.

 

[mtlogcabin]

I would look at 1026.6 Exterior ramps and stairway protection and see if you may have overlooked something.

As long as you have unrestricted access into the other building I don't see a problem

 

[Builder Bob]

The concept may be allowed, however, be sure to check the required seperation of the exits ---- The post leaves alot of room for imaginations to paint bleak pictures... such as the landing for the only stair tower in building A has the connecting bridge to the only stair tower in building B......

The pedestrian walkway has been used for years as providing a path for an exit. Usually the wall area adjacent to the pedestrain walkway is rated for two hours thus qualifies as an hortizontal exit as well.

 

[cda]

Not sure if continuity of exit would kick in?

Since you are in a rated exit than go to a non rated exit

More than likely not since you are outside the building

There was a similar discussion of a building with one exit, will have to look for it

 

[nealderidder]

Thanks for the input everyone! It does seem like a workable design. It may come down to what the rating of the wall is where the bridge connection occurs. The bridges will be constructed of non-combustible material and not have any fuel readily available so it should get people to where they need to go.

A colleague and I were discussing the many nuances of the building code this morning, even after many many times of doing this I still run into these little puzzles. It's great to have a board like this with the collective knowledge to compensate for my particular ignorances.

 

[Architect1281]

If as inferred that the Open Bridge is accessing one of two required means of egress you would review the "looks like two buildings" as a single structure and the Bridge / exit access would be very much like a corridor, the other code route would be to consider it as a "Horizontal Exit" depending on your seperations that would be required for that method

 

[JPotter04210]

I am envious as I've always wanted to design a pedestrian walk between two buildings.

Such is the exciting life of an engineer!