# additional sprinkler heads and revised calcs?



## cheyer (Nov 3, 2009)

Hello,

I would like to get a feel for how other jurisdictions handle the issue of additional sprinkler heads in the field that are not represented on the approved plans.

Some contractors and designers will reason that it doesn't matter if there are 150 additional heads as long it is not additional square footage added or if it is beyond the most remote calculated area......if it is a two head calc (13d), then that's all that matters...

I see the logic here, but how are other AHJ's handling?

Thanks.


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## FM William Burns (Nov 3, 2009)

Re: additional sprinkler heads and revised calcs?

Hello Cheyer and welcome!

In the event the heads were of the same type and style with no additional design issues for hazard protection, supply or coverage, I have historically found no issues.  With that being said, I do verify that there are no potential coverage issues that could present problems with head (or lack thereof) activation in the areas where the additional heads are added.

BTW...... If 150 heads were added into a project, I would triple check the design and firm submitting the plans


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## TJacobs (Nov 3, 2009)

Re: additional sprinkler heads and revised calcs?

I would want as-builts for sure... :roll:


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## JBI (Nov 3, 2009)

Re: additional sprinkler heads and revised calcs?

Cheyer - Welcome to our little corner of Codes Heaven.

As Jake suggests, an as-built wouldn't be a bad idea. Extra heads probably aren't a bad thing, within reasonable limits.

Just make sure they justify putting an extra head between two doors in a single opening like that museum in Boston did, right FM W B?  :lol:


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## hazmatpoobah (Nov 3, 2009)

Re: additional sprinkler heads and revised calcs?

The contractor is failing to tell you a very important variable: *what type of sprinkler is being installed?*

I am very, very leery of any FD policy that states if you have less than X sprinklers then no plan review is required. Frankly, its a dangerous precedence. With all of the special sprinklers (a defined term in NFPA 13) out in the world, I can easily sprinkler a 5,000 square foot building using less than 13 sprinklers if its light hazard and the building is of noncombustible construction with smooth ceilings. I would be required to prepare calculations if I was a designer - I believe its important that the fire code official review these drawings and calcs to make sure the sprinklers are installed in accordance with its listing.

If your dealing with standard 1/2 inch (K = 5.6) sprinklers that are not quick response, then such a policy is warranted, as long as the contractor or designer is not doing something stupid like installing 16 sprinklers on a 1-inch diameter, 180 foot long armover (yes, it was attempted once here in Idiotburg, USA by Billy Joe Bob & Wanda LuLu Fire Protection).

Finally, remember this. If you look in the IBC and IFC for all of the concessions in a building protected by NFPA 13, designers get a lot of credit (in some cases too many in my opinion) for a sprinkler system. Don't chance it, especially when special sprinklers are being used. Require the plans, calculations, and smile when they whine.


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## cheyer (Nov 3, 2009)

Re: additional sprinkler heads and revised calcs?

Group,

Thanks for the replies....it's great to have another place to bounce ideas and share experiences.

Chris H.


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## TJacobs (Nov 3, 2009)

Re: additional sprinkler heads and revised calcs?



			
				hazmatpoobah said:
			
		

> The contractor is failing to tell you a very important variable: *what type of sprinkler is being installed?*I am very, very leery of any FD policy that states if you have less than X sprinklers then no plan review is required. Frankly, its a dangerous precedence. With all of the special sprinklers (a defined term in NFPA 13) out in the world, I can easily sprinkler a 5,000 square foot building using less than 13 sprinklers if its light hazard and the building is of noncombustible construction with smooth ceilings. I would be required to prepare calculations if I was a designer - I believe its important that the fire code official review these drawings and calcs to make sure the sprinklers are installed in accordance with its listing.
> 
> If your dealing with standard 1/2 inch (K = 5.6) sprinklers that are not quick response, then such a policy is warranted, as long as the contractor or designer is not doing something stupid like installing 16 sprinklers on a 1-inch diameter, 180 foot long armover (yes, it was attempted once here in Idiotburg, USA by Billy Joe Bob & Wanda LuLu Fire Protection).
> 
> Finally, remember this. If you look in the IBC and IFC for all of the concessions in a building protected by NFPA 13, designers get a lot of credit (in some cases too many in my opinion) for a sprinkler system. Don't chance it, especially when special sprinklers are being used. Require the plans, calculations, and smile when they whine.


This is what I meant to write...especially the underlined part...


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## cda (Nov 3, 2009)

Re: additional sprinkler heads and revised calcs?

TJacobs

"""This is what I meant to write...especially the underlined part... """"

yea right, just missed a few keys???


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## FM William Burns (Nov 3, 2009)

Re: additional sprinkler heads and revised calcs?

As only Haz can do.........I will stand by what I said since Haz has explained it in a little more HP detail


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## Frank (Nov 4, 2009)

Re: additional sprinkler heads and revised calcs?

It is a judgement call based on where and how many heads.

Heads added in added closets or small rooms not an issue.

Multiple heads added on same branch line in remote area to create 2 rows on either side of a soffitt--big issue.


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