# 13D 4 head calc. or FDC reqt.



## cheyer (Jun 9, 2010)

Any AHJ's out there that have a local ordinance requiring a four head calc. on a 13D system when the residence is greater than 10,000 sq. ft.? If so, how do you justify it?

How about an FDC requirement for the same size house, and its justification?

I'm trying to clean up some "regulations" that have been floating around my Dept. for some time, and If I can't legally amend an adopted standard, I will just kick them loose.

Thanks in advance.


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## Builder Bob (Jun 14, 2010)

Not sure if any legal backing exist....... Nothing in the IRC limists squarefootage, 13 D doesn't have any square footage limitations, etc.

However, it will be important to remind people that a 13 D or a 13 R system is for life safety to the extent that it keeps the room of fire origin from reaching flashover for 10 minutes...... It is not for property protection like the 13 system is.

A fire in a 15,000 S.F. house may still burn to the ground with a 13 D or a 13 R system.... it just allows rescuers an opportunity to save a victim in the room of origin since they generally will not arrive on scene until 10 minutes after a fire starts...............


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## Glennman CBO (Jun 15, 2010)

I find people trying to mix the (3) 13's, trying to require things that are in 13, in a 13D application (or 13R). One has to discipline himself. They are (3) distinct standards.

That's the issue in our jurisdiction anyway.


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## hlfireinspector (Jun 15, 2010)

Seems I saw something in this BB about a residence over so many square feet could not be built under IRC and had to be IBC? That would push the sprinkler to 13R 4 head calcs?


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