# What call would you make?



## charlie (Mar 29, 2011)

A fire destroys a SFR. All that is left is a utility basement. Are you required to rebuild to current codes (fire sprinklers)?


----------



## JBI (Mar 29, 2011)

Location? Code? Year? Generally speaking, yes if you are enforcing the 2009 IRC.


----------



## charlie (Mar 29, 2011)

California, 2010 CBC and 2010 CRC which is based on the 2009 IRC


----------



## mjesse (Mar 30, 2011)

Here, we would require that all new work be built to currently adopted Codes.

I would also ask for an PE's stamped letter stating that the existing foundation is suitable for the proposed new construction to be built on.

Worst case, you may have to remove the foundation and start from scratch.

mj


----------



## jj1289 (Mar 30, 2011)

I agree with mjesse


----------



## Alias (Mar 30, 2011)

charlie said:
			
		

> A fire destroys a SFR. All that is left is a utility basement. Are you required to rebuild to current codes (fire sprinklers)?


Charlie -

Yes, I would require the new SFR to be built to current code, 2010 CRC including sprinklers. SB 726 hasn't been passed so we're stuck with the sprinkler requirement.

I also agree with mjesse on the foundation inspection.


----------



## FredK (Mar 30, 2011)

jj1289 said:
			
		

> I agree with mjesse


Same here.


----------



## fatboy (Mar 30, 2011)

Ditto to mjesse..........


----------



## pwood (Mar 30, 2011)

i would require compliance with the current codes.


----------



## Forest (Mar 30, 2011)

Requires current codes


----------



## NH09 (Mar 30, 2011)

mjesse said:
			
		

> Here, we would require that all new work be built to currently adopted Codes.I would also ask for an PE's stamped letter stating that the existing foundation is suitable for the proposed new construction to be built on.
> 
> Worst case, you may have to remove the foundation and start from scratch.


Same situation here in NH, although it is now against the law to require residential sprinklers - if you can believe it.


----------



## MarkRandall (Mar 30, 2011)

Excuse my ignorance, but what effect could a fire have on the concrete foundations and by what methods would an engineer analyze it.


----------



## permitguy (Mar 30, 2011)

Excessive heat causes loss of compressive strength in concrete.  A specialized concrete hammer can be used to test the compressive strength in a non-destructive manner.

NH09 - New code amendment:  All homes must be constructed of non-combustible materials.  Exception - homes sprinklered in accordance with IRC 2904, NFPA 13, NFPA 13R, or NFPA 13D.  Problem solved.


----------



## brudgers (Mar 30, 2011)

Heat tends to rise, in a dwelling fire the odds are that the foundation did not see enough heat to affect it.


----------



## permitguy (Mar 30, 2011)

Knowing nothing about the fire, that's a pretty bold assumption.  Good advice for building officials that like to play odds, though.


----------



## SteveT (Mar 31, 2011)

Could they make a case in that building on the existing foundation is an addition to an existing structure and therefore does not require a sprinkler system?


----------



## mjesse (Mar 31, 2011)

MarkRandall said:
			
		

> Excuse my ignorance, but what effect could a fire have on the concrete foundations and by what methods would an engineer analyze it.


It's not so much the effect of the fire on the foundation I'm concerned about. The bigger issue is that the newly designed framing, steel, floor loads, etc. could be different than originally built, and the existing foundation may not be suitable.

Hypothetically: House was built in 1949, 8" trench foundation, 2x8 floor joists, single story, 2x4 rafters, etc.

New house is 1-1/2 story, open floor plan, LVL's = point loads, 2x12 rafters with tile roof, etc.

What it was, and what it will be are most likely going to be different. I want to know the foundation is suitable. That's all.

mj


----------



## mjesse (Mar 31, 2011)

SteveT said:
			
		

> Could they make a case in that building on the existing foundation is an addition to an existing structure and therefore does not require a sprinkler system?


We use the term "Substantially Remodeled" based on 50% or greater of the current value as determined by the Tax Assessors office. Since the _only_ thing left here is the foundation, I don't think it's unreasonable for everything above "new work" to comply with current code.

"Addition" to a structure that only exists below grade seems like a tough sell.

mj


----------



## permitguy (Mar 31, 2011)

Welcome, SteveT!

It's an interesting point.  How much of the house must be gone before you call it a rebuild?  Conarb has talked about contractors leaving a single wall intact so they can call it a remodel instead of a new home.  That isn't something I would permit if I were the building official.  If there's nothing left but a foundation, I think you've got to follow all current codes to the extent technically feasible.

If this were an older home being rebuilt to the same floor plan, there are things which may not be possible to accomplish to current standards on an existing foundation.  I would do my best to remain flexible on those things.  Stair geometry comes to mind, as does hallway width and general room dimensions.  Sprinklers would not be a technical infeasability, though.



> It's not so much the effect of the fire on the foundation I'm concerned about.


If an engineer assumes no loss in compressive strength and only considers foundation size, point loads, and soil bearing capacity after a fire, he shouldn't be in this business.  IMHO, you really should ensure he checks for detrimental effects to the foundation from the fire.


----------



## brudgers (Mar 31, 2011)

permitguy said:
			
		

> Knowing nothing about the fire, that's a pretty bold assumption.  Good advice for building officials that like to play odds, though.


One thing I know about the fire - heat is risen.

I didn't say that engineering shouldn't be required (because new loads may not be the same as old loads), only implied that the holding a concern which is contrary to the laws of physics often correlates with specific ignorance of said laws or general stupidity.


----------



## mtlogcabin (Mar 31, 2011)

> One thing I know about the fire - heat is risen


I thought Christ was the only one risen  

It would depend on the fire. Did the fire start in the basement, did the floor remain intact or did or did all the burning debris fall into the basement. Heat radiates so depending on a number of variables a fire could could have a ngative effect on a basement wall


----------



## permitguy (Mar 31, 2011)

> I didn't say that engineering shouldn't be required (because new loads may not be the same as old loads), only implied that the holding a concern which is contrary to the laws of physics often correlates with specific ignorance of said laws or general stupidity.


Coming from someone who obviously knows nothing of fire behavior beyond where to hold the marshmallow stick, I won't concern myself with your impression of my intelligence.



> It would depend on the fire. Did the fire start in the basement, did the floor remain intact or did or did all the burning debris fall into the basement. Heat radiates so depending on a number of variables a fire could could have a ngative effect on a basement wall.


Precisely.


----------



## Paul Sweet (Mar 31, 2011)

Another concern would be whether the collapsing structure put any lateral loads on the basement walls, especially if they're concrete block.


----------



## RJJ (Mar 31, 2011)

I agree with FredK &FAt to current code.

One question is this the Charlie from the ICC BB?


----------



## fatboy (Mar 31, 2011)

I wondered the same thing, I was thinking not, he doesn't seem quite cantankerous enough!


----------



## DRP (Mar 31, 2011)

repeated, deleted


----------



## Architect1281 (Apr 3, 2011)

Yes current code - no sprinklers - RI made optional


----------



## cboboggs (Apr 4, 2011)

Structure must be rebuilt to current codes and we would require an engineer's report on the foundation.


----------



## David Henderson (Apr 4, 2011)

Agree with cboboggs


----------

