IRC Tables R302.1(1) Exterior Walls and (2) Ext Walls w/ Fire Sprinklers

[JBI]

Just curious... Does any one know why the 2012 and 2015 IRC include both tables when all new ResCode dwellings now require Fire Sprinklers?

I believe I have figured it out, but was wondering if any one actually knows why (2012 Commentary is silent on it...)

 

[mtlogcabin]

For all the jurisdictions that amend out the sprinkler portions.

 

[mark handler]

There are also cases of remodels of existing residences that do not trigger sprinklers

 

[JBI]

mtlog - That was my knee-jerk reaction, but those jurisdictions could easily retain the old table.

So I thought about it some more and looked a little deeper which is when I came to the realization that mark h brought up (above).

The IRC does not contain provisions in Appendix J for 'Additions', but regulates them in the main body of the IRC.

In the Sprinklers Section there is an exception for existing dwellings and additions to existing dwellings.

I was just poking around here to see if anyone had a different reasoning... or an 'inside scoop'.

 

[steveray]

Prepping to remove RFS? Or at least provide alternatives....

 

[cda]

They did not give an alternative for townhouse walls, non sprinkled

So can't see preping

 

[Francis Vineyard]

In summary the exterior wall provision and townhouse separation are separate requirements that are not tied together.

The 2012 exterior wall "provision recognizes that some state or local jurisdictions may not have enacted the sprinkler requirement and offers and alternative for builders choosing to install automatic sprinkler systems."

The 2015 realized that "jurisdictions amending the IRC to remove the fire sprinkler requirements may not be amending the common wall provisions to reflect the 2-hour fire-resistant rating."

The 2015 also removed the provision for structurally independent fire-resistant wall in favor of the common wall.

Also new in the 2015 IRC unprotected roof overhangs are permitted to project to within 2 ft. of the property line in accordance with foot note a and b.