Obstructions to ESFR heads due to Lights

[RedlineFP]

Hello Forum,

I am working on a project with ESFR system for a Tire Storage warehouse. (SH -25' & BH - 30'). The design is done and approved by EOR. The final electrical shop drawings just came out and they have proposed to use lights 30" wide X 26" deep. This creates a bit of issue for us as per 8.12.5.2 (1) NFPA 13 - '10 which would require sprinklers below these lights throughout the warehouse (we're talking 140,000 Sq. ft). The owner neither wants to pay extra for sprinklers nor wants to change his lights. We figured that the only code compliant solution to this would be to raise the lights(26" deep) tight to the deck and as the deflectors are 14" below the deck, if we follow the Table 8.12.5.1.1 and keep lights 3'-6 to 4'-0 off of heads. I am not sure though if I can use this Table or not.

I will really appreciate if the forum can provide the commentary on this issue.
Thanks.

 

[TravisMack]

If the lights are held tight to the roof deck, then I guess this would appear to be a legitimate use of the table. This table is for obstructions that are tight to the roof deck (like a structural beam would be). I would say that if they have the lights hanging down a couple inches, then this would not be acceptable.

You are going to be extremely limited in what you can do because of spacing limitations. If you are 3'6" from each side of the light and the light is 2'-6" wide, then you have a zone of 9'-6" where the sprinklers can NOT be located. You have a max of 12' spacing on your sprinklers with a roof height not exceeding 30'. However, you still have 100 sq ft max. You are going to have a very tough time being in compliance with structural obstructions and these lights. Also, the lights were probably figured to be below the structural members. Now, there are going to be shadows everywhere as the lights will be above the structural bar joists. Has the electrical engineer been consulted on this? Will they still meet all of the lighting requirements if you raise the lights as indicated?

I'm sure the owner doesn't want to pay for anything additional. However, some one dropped the ball in this and there is going to be costs incurred to fix it. I learned long ago that we have specs in all of our ESFR bids that lighting shall not exceed 23" in width at the widest point for the areas with ESFR sprinklers.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[Sdpaddler50]

I have dealt with this many times before. Lighting contractors obstruct more heads than any other trade.

The ball was dropped, and my guess is everyone is a little guilty.

If you raise the lights Above the heads you are ok. Easier said than done, but something to think about.

Did you look at FM 2-0 if ahj will accept it. Not saying you will find any relief in that guideline, but you can check.

I the future, put very clear notes on your plans depicting "no fly zones" around heads. You need to understand every aspect of the structure, lighting, conveyors..the list goes on.

During the initial, pre const meetings with the trades you need to stand up and say "don't obstruct my heads!" And go on record in writing to that affect.

Sorry, don't mean to sound harsh, but if you are designing an ESFR job you have to do your due diligence.

 

[LCREP]

As an insurance AHJ this is a huge problem. Before a job starts I send a letter to the owner to advise of the ESFR obstruction problem. Before the job starts I go to the job meeting and inform all the contractors, even give them a copy of NFPA 13 and go over it. I go around the room and ask each trade do they understand it and if I find an obstruction they will pay for it not my client, the building owner.

EVERY time I do this I hope they get it and I will find no obstructions.....THEY still do not get it. When I find something I tell them to move it. They start telling me how much it is going to cost and who is going to pay for it? I remind them of our meeting and the letter and NFPA 13 section I sent them. The conversation soon ends with "we will move it".

The problem is the insurance carrier is not always involved in a project and many carriers do not have an engineering dept. So hold your ground eventually some insurance engineer will walk into the building and point out the same problem you have identified. Since this is a tire warehouse not many carriers will have the capacity to write the large $$$$ so perhaps it will go out to insurance company with an engineering dept.

Oh yea obstructions are not only lighting. I see HVAC, bar joist, bridging, cable/computer wire, roof drains, ceiling fans, conveyors......

 

[RedlineFP]

TravisMack- You're correct,Those are similar points I included in our proposed solution to resolve the issue but they don't want to lift the lights tight up to the deck because as you said, it will have shadows due to bar joists below.
Now I can't use the Table 8.12.5.1.1. We have been requesting for final Electrical plans from so long.

The main problem is that the owner has one more warehouse similar size built couple of years ago and they have used same lighting but nobody raised any questions. So he figures that we are trying get more money out of him showing all these obstruction rules requiring extra sprinklers. I did visit that warehouse he is talking about and the lights were right next to sprinklers but i guess nobody questioned it or they were installed after the EOR signed off on the system.

Sdpaddler50 & LCREP - I appreciate your comments. I did take care of the obstruction from HVAC & Joists. I had electrical plans for review with no details on lighting and based on those NFC plans I did keep my heads 2ft away from lights assuming that lights won't be wider than 24". I accept that it's negligence on my side ASSUME things while I am designing An ESFR system especially for such hazardous commodity. I will make sure to include notes on my dwgs and in our quotes as well.

 

[Sdpaddler50]

Redline,

It sounds like have done your homework on alot the aspects, so I apologize if I came across like I was lecturing you.

I think we all get really frustrated with this subject, because the obstruction issue is so prevalent.

As noted by others on this board (Stookey, TM, Lcrept, the list goes on), there is this belief among developers, clients, and some insurance companies, that if ESFR are installed, all is good. There are so many ways these jobs can go south. I wrote an article in the SFPE magazine many years ago about this subject. Ping me, and i can send you a link if you want to see it.

Did you ask the electrical contractor to use smaller dim lights, to stay at the max 2 ft wide dim you note? These new "T" lights are bright, so perhaps a smaller profile light?

Did you look at FM, 2-0? They wrote the book on these things, so you may find some help there. You can get free access to their Data Sheets by registering on their website.

 

[TravisMack]

Redline:

I have been in that situation before. We do a job that some one else did things wrong on a prior project. We are trying to do them right and get accused of everything under the sun. At times, I have said, "It is too bad that you didn't hire a competent individual the first time. Now you have to go back and fix the problem in the existing building as well."

Unfortunately, so many think that you put ESFR in and it is all good. Unfortunately, you almost have to build the building around the ESFR sprinklers. To quote Uncle Ben. "With great power comes great responsibility!" ESFR are very powerful tools in fire protection. However, all parties have a great responsibility to insure compliance with all parts of the building.

It sounds like it is going to come down to the electrical guy is going to have to change the lights to a size that is compliant with NFPA 13 criteria. If not, it is time to start circling the wagons. Get your attorneys to draft letters to all involved about the issues. You do not want to be "forced" into completing this project, then having a fire not controlled later on and the building or worse, a life, is lost and you are deemed responsible due to non-compliant fire suppression design. Now, that may be way extreme, but I always make these kind of decisions on that extreme thinking.

Good luck with it. I really hope you are able to educate those involved so that this doesn't happen in the future.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[RedlineFP]

Sdpaddler50 - NO sir, Not at all. I took yours/everyone's comments in a positive manner to learn from my mistakes and as I said I will try to make sure in the future that something like this doesn't happen again. I am 23 years old and in 2nd year as a designer.

EOR won't accept any deviations from NFPA as he wants us to follow the more restrictive standard. The owner wants these lights only and I guess we are going to eat up the cost for almost 160 heads.

TM: "Unfortunately, so many think that you put ESFR in and it is all good" - Exactly the case here with me as well. It came down as my mistake that I Didn't design the system good enough to accommodate other trades.

I was very nervous for last couple of days, Job was almost 70% fabbed and I thought I was gonna loose my job thinking that I screwed up big time but I really appreciate the help from the forum.

Thanks.

 

[TravisMack]

A couple more things that may crop up to bite you in the rear.

1 - If you put pipe and sprinklers under the lights, that is going to create shadows all over. Is that going to mess with the lighting requirements? The EE will have to verify that or not.

2 - What edition of NFPA 13? If you are 2010 or older, you are required to include up to 2 ESFR sprinklers below your obstructions. So, with something like this, you may be calculating an additional 1-2 sprinklers in your remote area and this could kill your pipe sizing. If you are under NFPA 13, 2013 edition, you are not required to add the sprinklers below an obstruction in your calcs. However, the pipe to the sprinkler under the obstruction must be the same size as your branch lines.

Again, I hope this works out for you. 2 years experience is pretty early for doing something as sensitive as an ESFR system without a lot of internal review of the project. Don't beat yourself up over this.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[Sdpaddler50]

I can tell from your replies that you have integrity. You will be fine in the long run and a valuable member to the fire protection community.

I remember the first couple ESFR projects I was involved with, and I was your exact age. I can tell you I also took some lumps, but that is how we learn. Heck, I still do.

Lastly, the company you work for should have provided more support. Ie, a more experienced designer to oversee as previously noted. This is not just your issue.

Anyway, best of luck to you and I hope things work out.

 

[RedlineFP]

Travismack :

1. Correct but what I heard from them guys is that shadows due to pipes and sprinklers will be not quite as much as from bar joists and considering very limited options we have, they will live with that. I use AutoSprink here and I submitted revised plans with heads beneath lights with a very clear details.

2. I am using 2010 edition. i did calculate 13 heads in my original design considering the commodity that is being protected. "However, the pipe to the sprinkler under the obstruction must be the same size as your branch lines."
This applies only in 2013 edition when I am not calculation any extra heads, Right ?

 

[TravisMack]

Yes. It only applies if you do not calculate the heads as required in earlier editions of NFPA 13.

Autosprink is about the best program you can be using. I am sure you will love that program as you get even more familiar with it. I have been using it for about 10 years.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com