Take the 2-minute tour ×
Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. It's 100% free, no registration required.

I'm planning to add several rows of fluorescent light fixtures in my garage, which has partly recessed fire sprinkler heads. Does code specify how close fixtures can be to the sprinklers?

Common sense says the lights should not block the sprinklers, but I'm not sure how far that really would mean. The light fixtures I would like to use are about 4" tall.

Finally, if surface mounting lights nearby is an issue with code, what about recessed lights?

share|improve this question
add comment

3 Answers 3

up vote 4 down vote accepted

I was able to track down the relevant code document for residential sprinker installations - it's 2010 NFPA 13D, section 8.2.5.2, and it's actually viewable online for free if you register your email address. There is a different code for commercial buildings. For this issue at least, the residential requirements are much more strict.

The residential code says pendant sprinklers must be at least 3 ft from obstructions such as ceiling fans and lights (as measured from their centers), or you can use this table which relates A) the distance from the sprinkler to the near edge of the obstruction and B) height of the sprinkler's deflector above the bottom of the obstruction.

ceiling----------------------------------------------
              |                  *               *
  sprinkler  -+-      ---        *  obstruction  *
                       B         *               *
                      ---        *****************

              |<----    A   ---->|


---------------    --------------
Distance A (ft)    Maximum B (in)
---------------    --------------
up to 1.5          0
1.5 - 3            1
3 - 4              3
4 - 4.5            5
4.5 - 6            7
share|improve this answer
add comment

The sprinklers spray at an angle of approximately 45 degrees. So of your light fixture is 4 inches deep, then you should keep them at least 4 inches away from the sprinkler heads.

Also, I know that the light fixtures in our office are immediately adjacent to the ceiling tiles that have the sprinkler heads in the center and the ceiling tiles are 24 inches. So 12 inches seea to be acceptable.

share|improve this answer
    
I thought 45 degrees sounded pretty reasonable, but turns out the code is much more strict when the lights are not recessed. –  JayL Aug 18 '11 at 6:40
    
Ok, that makes sense. I saw sprinklers for residential installation at my local hardware store the other day and I was stuck by how flat the fan plate thing that disperses the water was compared to the ones at my office. I know from first-hand experience that the ones at work spray at a 45 degree angle, but the ones I saw would definitely spray almost horizontal. I'm glad you found the code. Good answer! –  longneck Aug 19 '11 at 3:54
add comment

I'm looking at our recessed-head FSS, and I see one head cover less than 6 inches from the nearest fluorescent light. This is a drop ceiling, though (standard office space construction), so the cover and the bottom of the light pan are at the same level, so there's virtually no chance of the sprayer hitting anything energized.

share|improve this answer
    
I noticed the same where I work, but in my case it would be a real hassle to do recessed lights. –  JayL Aug 18 '11 at 6:38
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.