we are designing a new school building that is going to be built adjacent to the existing school which will be demolished when the new building is completed. my question is what separation distance do we need to maintain so that exterior walls will not need to be rated? the new building will not be occupied until after the existing building is demolished.
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separation distance when building next to existing building that is going to be demolished.
- Thread starter ccollings
- Start date
steveray
SAWHORSE
Ask the AHJ if they will allow it temporarily?
Ideally... I'd say that each building should comply with Table 602 just in case the building does not come down immediately.
As the AHJ, you could get some type of agreement for timeline. That said, keep in mind that construction is one of the most dangerous times in a buildings life with regards to a fire breaking out. If the other building (the existing one) is occupied, and a fire breaks out in the new building that likely does not have an active FS system, what is the level of risk? Is the BO comfortable with that risk?
As the AHJ, you could get some type of agreement for timeline. That said, keep in mind that construction is one of the most dangerous times in a buildings life with regards to a fire breaking out. If the other building (the existing one) is occupied, and a fire breaks out in the new building that likely does not have an active FS system, what is the level of risk? Is the BO comfortable with that risk?
Genduct
REGISTERED
With Type 1 or 2 Construction material and No Content ( except Bldg material) seems like Risk Assessment would say this is a Low Risk situation
IMHO Mike
apparently you have never seen unfinished buildings burn. And it could be arson the week before opening,when all the furniture is installed.
Not likely Type I; probably Type II. But it is a school... pretty high risk if you ask me.
Genduct
REGISTERED
Risk Assessment is not based on Criminal Acts Like ARSON
We had an example of what you are suggesting in Conshohocken several years back when they completely Framed, but didn't close in a sister 4 story multi-family bldg. the bonfire was so hot it set the exterior of the type 5 construction with the radiant energy, The fire was so hot it melted the blacktop and Cooked several of the Fire Fighting Appartus, SO, yes, I have seen examples of accidental loss.
Still, I think that this replacement Bldg is not wood frame, it is steel structure with decking and concrete and drywall and is pretty safe when built and even during construction.
The Risk Assessment is LOW, Not NO chance of a loss IMHO
You can get an insurance rider. I am sure the Underwriter will set the Premium at an affordable level to prove in dollars and cents what that rick is
Mr. Inspector
SAWHORSE
Ask for a fire watch. Someone there 24 hrs starting at new school C. O. until demo is done to old school.
steveray
SAWHORSE
Very low risk to life....
But property may be another matter, maybe ask their insurance provider how they feel? I have never seen a non-combustible building burn during construction....
Paul Sweet
SAWHORSE
What is the construction of the existing school? Most older schools of masonry construction would have a 1 or 2 hour fire rating.
Could they close in the windows with rated drywall, or not use the classrooms immediately adjacent to the new construction?
Could they close in the windows with rated drywall, or not use the classrooms immediately adjacent to the new construction?
mark5211
REGISTERED
Per T602, no FRR required for 30' and greater to assumed or actual property line. So if buildings are 60' apart, then exterior walls are not required to be FRR for FSD/T602. Be sure to refer to T601 for exterior walls that are required to be FRR per construction type.
I think we're going to try to stick with a 30' separation distance. right now, this is all academic. we don't have the project. we're putting together a design proposal. it's a very tight site. The existing school is an L shape. The new building will be an inverted L.
Paul Sweet
SAWHORSE
An E occupancy of IIB or VB construction only requires a fire separation distance of 10 ft. for unrated walls, according to T602. Other construction types require rated walls because they are a requirement of the construction type, not distance. (Clear as mud) T705.8 gives you the maximum opening percentage.
yeah. like tetris. Only way to get everything to fit. the question being, how close to existing can we get. the closer we can get the more landscape buffer from the neighbors we can have. programmatically with all the window openings it will be hard to rate the exterior wall and of course the existing building doesn't have any rating.
If we get the job, we'll have to sit down early on with the ahj and review.
this will be 2B construction. I'm assuming that the existing building is also 2B (face brick on cmu). realistically, with the existing school being in use during construction, i wouldn't want to go closer than 20'.
Genduct
REGISTERED
So< I believe that is 10 ft to real or theoretical Property Line, that would be 20 total feet for your example