Flat Concealed Spaces <36" deep

[TravisMack]

I am running into this again. What is the consensus here on the sprinklers that are required to be used when you have a concealed combustible space that is less than 36" deep and has a slope of <2:12?

It is my understanding that you are required to use the specially listed sprinklers (Viking COIN or Tyco CC1/CC2) in these spaces. These heads also require draft curtains to be installed in the concealed spaces.

I have an architect and consultant that are fighting us and saying it is not required. Granted, this consultant had a drawing with several issues on it, but this is the biggest issue on the project.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[chillylulu]

TravisMack - I think the code conflicts, but ultimately I agree with you.

NFPA 13 - 2010 states the following:

1st:

"8.3.1.1* Sprinklers shall be installed in accordance with their
listing.
8.3.1.2 The requirements of 8.3.1.1 shall not apply where
construction features or other special situations require unusual
water distribution, and listed sprinklers shall be permitted
to be installed in positions other than anticipated by their
listing to achieve specific results."

"A.8.3.1.3 The purpose of this requirement is to minimize the
obstruction of the discharge pattern."

"8.4.1 Standard Upright and Pendent Spray Sprinklers.
8.4.1.1 Upright and pendent spray sprinklers shall be permitted
in all occupancy hazard classifications and building construction
types."

"8.15.1.3 Concealed Space Design Requirements. Sprinklers
in concealed spaces having no access for storage or other use
shall be installed in accordance with the requirements for
light hazard occupancy."

Seems the architect / consultant could argue that standard uprights can be used. Even though they are not specifically tested in an area with a 36" height. And since the area is not compartmentalized per the interstitial heads listing, the standard uprights would at first look seem to work. Whereas the space, without modification, does not work with the interstitial heads.


2nd:

"8.15.1.6 Sprinklers used in horizontal combustible concealed
spaces (with a slope not exceeding 2 in 12) with combustible
wood truss or wood joist construction having a combustible
upper surface and where the depth of the space is less
than 36 in. (914 mm) from deck to deck or with double wood
joist construction with a maximum of 36 in. (914 mm) between
the top of the bottom joist and the bottom of the upper
joist shall be listed for such use."


This section was added in the 2007 edition of NFPA 13. It was probably originally submitted by one of the manufacturers to try to sell more interstitial heads.

That being said - there always is a liability concern. I would prefer to install sprinklers in an area for which they have been tested, and for which they are specifically listed. By providing the draft stops and using the interstitial heads the level of protection is known. By using standard uprights the level of protection has not necessarilly been verified with testing. Just because "it was always done that way" doesn't make it right.

See if the architect and consultant are willing to sign something that releases you from liability for their decision.

Another advantage to using the interstital heads is that you can install plastic pipe in the space.

 

[TravisMack]

Unfortunately, CPVC is not an option with the local AHJ. Don't ask, just one of those things you deal with in this industry.

I don't have a copy of the handbook, but I had heard that in the commentary of the 2010 edition of the handbook, it talks about testing of SSU's in the attic spaces and how it did not perform well. That was the reasoning for the development and requirement of these flat spray sprinklers.

The issue is one of terminology. The architect states that since the project is sprinklered per NFPA 13, that draft stops are not required. I told him that he is correct. However, these sprinklers require draft CURTAINS as detailed in the data sheets.

Also, he is telling me that he has done this type of attic on several projects and has never had to deal with this. I stated that I guess they have done several wrong, and it is time to break the pattern of being wrong.

I also did get confirmation from the engineering department of NFSA that they also agree that the specially listed sprinklers are required in these areas.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[chillylulu]

Travis, I feel you are right.

We will always be educating our customers, the ahj's & everyone.

The problem is, they think we are trying to pull a fast one.

Good Luck

Larry

 

[cdafd]

8.15.1.6 Sprinklers used in horizontal combustible concealedspaces (with a slope not exceeding 2 in 12) with combustiblewood truss or wood joist construction having a combustibleupper surface and where the depth of the space is lessthan 36 in. (914 mm) from deck to deck or with double woodjoist construction with a maximum of 36 in. (914 mm) betweenthe top of the bottom joist and the bottom of the upperjoist shall be listed for such use."


is this scetion telling you to use listed heads for this condition??? seems not to be written that way???????

 

[TravisMack]

CDA:

In talking with reps at AFSA and NFSA, I have been told that the intent is to use the specially listed sprinklers in these spaces. I received the same information from the tech reps at Tyco and Viking, but I initially took that with a "grain of salt" as the answer seemed self serving.

I have had this come up quite a few times lately and have also talked with other colleagues in various parts of the US. All seem to agree that when you have the flat concealed spaces <36" deep, then you need to use the specially listed sprinklers.

However, since the requirement came out in the 2002 edition of NFPA 13 (just worded a bit different), I have yet to see an architect or consultant include it in the plans. It always comes up in the shop drawing preparation and causes a "fire fight" between the architect / GC / Consultant and sprinkler contractor as to who is responsible for the draft curtains and if you have TJI, who is responsible for the insulation and making sure it is wired in.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[cdafd]

I am missing the draft Curtain requirement

What code/ standard section edition does it come from??

 

[TravisMack]

You have to go to the datasheet for the sprinkler. It very specifically calls out a draft curtain. Note, this is not a draftSTOP.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[cdafd]

ok now I see the requirement on the spec sheet

as an ahj, this seems like an inspection/design nightmare

 

[TravisMack]

Yes it is a nightmare. Plus, there has been very little education in the industry regarding this from what I have seen. It always leads to crazy problems.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[TravisMack]

What I hate is when I educate my customers about this type of stuff, so they bid it the proper way, but lose the job because another guy bids it with standard spray heads. The CC heads are a fair bit more expensive.

Or, one of my customers got in a nasty situation where he bid it with the proper heads, but the architect did not indicate any draft curtains or any of the requirements for the heads. The AHJ flagged it for lack of draft curtains per the sprinkler listing (this was an AHJ we educated about these on a previous job). Then, the GC tried to tell the sprinkler contractor that he was responsible for the costs of the draft curtains because the sprinkler heads required them per the listing. These heads serve a good purpose, but we need some way to educate the construction industry about the requirements when having concealed combustible spaces that are "flat" and <36" deep.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[cdafd]

finaly I see the light:

""""shall be listed for such use"""

 

[TravisMack]

That is the part that most don't see. Then, even if they see that, they often don't see all of the requirements in the datasheet for the heads, and there are a lot of them. They even differ slightly if using CPVC or steel pipe.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[cdafd]

sounds like the opening protection problem in department stores, only worse

 

[skdesigner]

Not worse. Note the data sheet only requires the draft curtain be "constructed using a material that will not allow heat to escape through or above the draft curtain". It's almost always cheaper and quicker for the sprinkler company to do it themselves.

Designer shows the locations and dimensions of the draft curtains on his plans, road supe buys a few sheets of OSB and a skil saw, and the fitters screw them to the joists as they go. You would probably spend more money going to co-ordination meetings to fight the GC/Architect, so why not put yourself in his good books right off the bat.

Or, mark your joists, buy the drywallers a couple bottles of hooch and have them throw some sheetrock up there as they are boarding the ceilings.

 

[TravisMack]

SK:

That is all fine until you get into a union market where the trades don't cross. In some of the markets, the sprinkler contractor has done that.

But, the question is why should the sprinkler contractor be required to do that? I have already had projects where the GC tries to get the sprinkler contractor to verify that the building is capable of supporting the sprinkler pipe (structural PE job), along with many other things like that. Soon, I can see a day when I get an aerial photo of a site and say "sprinkler contractor to provide building and sprinkler system for xyz use"

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[skdesigner]

I suppose I agree with you Travis. We shouldn't be "required" to do it. I just find doing certain things ourselves to be quicker. I'm sure you know how long requests for extras that the general contractor has to absorb can be drawn out, or get lost on his estimator's desk. In the meantime, the tin basher has hung all his duct exactly where we didn't want it to be, and now we're up a creek.

It's not like we pay fitters to do something like that. That's what apprentices are for.

"Soon, I can see a day when I get an aerial photo of a site and say "sprinkler contractor to provide building and sprinkler system for xyz use"

Shoot - when it happens, MEPCad will sell you a version of Autosprink with a "Draw Building" wizard in it. Should be fool proof.

 

[TravisMack]

That is too funny. I take it you are a MEPCad user as well. I love that program.

In the times when my customers have had the battle about the curtains, we give the GC a plan that shows the layout of the draft curtains and say we are providing protection based on these draft curtains. That way the fitters can keep installing. So, if the GC decides to stall on it, they just get to pay more when they finally put it in. It is just a pain that I have yet to see a single architect or engineer address this in a contract set of drawings.

I had to throw a well respected local FPE firm under the bus this week on a project where these heads were req'd. It was for a large chain hotel. During shop drawings, we indicated that it can't be done with SSU sprinklers as currently drawn. Went back and forth for a bit. We tried to just fix it and make it go away without much fuss, but the engineering firm would not drop it. They stated that they had done this on all of their projects in the past. He tried to bring this up in a meeting to make us look bad. I just left it as "Well, I hope your E&O is paid up and you have a plan B to escape to Belize should a problem ever arise because these requirements have been around since the 2002 edition of NFPA 13." He was not too happy!

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[pipesnpumps]

From above:"Also, he is telling me that he has done this type of attic on several projects and has never had to deal with this." ... "They stated that they had done this on all of their projects in the past."

As a plans reviewer, statements like the above used to make me laugh, but now I dread it.. Because that means they are still in phase 2 of the shock, denial, anger, bargaining, and acceptance sequence.

I tell them what they did on past projects doesn't change what is written on the paper in the code/standard. I also like to tell people that probably 98% of all commercial buildings have violations of at least one code or standard, and some have many violations, so it is not surprising they got away with it before but not this time.

Last year I had an engineer called me arguing my comment, and after asking, I found out he was using wording from a mid-90's version of the standard.. In two years I have heard it all; I can't imagine the stories I will accumulate if I keep doing this for 20 years..

Thanks for the heads up on these sprinklers. Great info! I rarely see type V construction, but I will watch for it.





Real world knowledge doesn't fall out of the sky on a parachute, but rather is gained in small increments during moments of panic or curiosity.