# Pot Light Boxes for Insulated Ceilings



## Sar-Con (Jun 23, 2010)

Guys,

I've got a ceiling with incandescent pot-lights in an insulated ceiling. I'm not sure if they're rated for insulated ceilings or not, but I can see light through them in the attic so I'm guessing not.

I'd like to build a box to put over top of them, air seal and insulate around it, all from the attic. Is there any code that speaks to this (that mentions materials to be used or minimum clearances) , or is this even acceptable? 

Thanks!


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## Reasononly (Feb 15, 2011)

*Can light air sealing*

Hey there, I sell insulation for SnE Insulation in Shorewood Wi. Those pot lights are a big thing here. The code used to allow you to use drywall and either foam or caulk but now your only supposed to use mason backer board and all the edges sealed with a fire rated caulk, clearance is 4" on all sides. Your not allowed to put insulation on top of the box. Hope that helps.

Erik


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## Inner10 (Mar 12, 2009)

They sell metal boxes for pot lights at home depot.


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## TxElectrician (May 21, 2008)

Pull the trim down and look inside the can. It will say if it is IC rated. If it is, no need to build anything around it.


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## thomasjmarino (May 1, 2011)

Pot lights, huh?????? :whistling


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## Reasononly (Feb 15, 2011)

*Wi air sealing*

When you use a metal cover or custom build a box for recessed lights your trying stop air flow due to stack effect, convection , and the warm air rises idea. You might not deal with that so much in Texas, but when you don't seal those up properly, you will promote mold, especially if the roof ventilation is inadequate or more times than not....ass-backwards.


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## Sar-Con (Jun 23, 2010)

Reasononly said:


> When you use a metal cover or custom build a box for recessed lights your trying stop air flow due to stack effect, convection , and the warm air rises idea. You might not deal with that so much in Texas, but when you don't seal those up properly, you will promote mold, especially if the roof ventilation is inadequate or more times than not....ass-backwards.


I had the roofing replaced, and the worst shingles were above the location of the pot lights. I increased the soffit and peak ventilation, now I have to either bite the bullet and replace 5 potlights, or build a custom box and seal and insulate around them. Just weighing my options...


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## The Coastal Craftsman (Jun 29, 2009)

Or change the bulbs for LEDs. I just did that in my office and it's unreal how they don't get hot. I used to run 50w halogens in there and they would heat the room up like a sauna.


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## SLSTech (Sep 13, 2008)

For non-IC rated http://www.tenmat-us.com/fire-protect-products.html


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## Morning Wood (Jan 12, 2008)

There is no harm whatsoever in air sealing those lights. As long as your clearances are correct and the light is rated for insulation. I'd use 2" rigid foam glued and sealed with spray foam.


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## Reasononly (Feb 15, 2011)

*might be out of code*

I am not sure if foam is rated for that, depending on the lights your using, you could box them with foam and change your lights to leds. Probably pretty safe there.


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## Morning Wood (Jan 12, 2008)

Reasononly said:


> I am not sure if foam is rated for that, depending on the lights your using, you could box them with foam and change your lights to leds. Probably pretty safe there.


Make sure you use proper clearances.


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## SLSTech (Sep 13, 2008)

Reasononly said:


> I am not sure if foam is rated for that, depending on the lights your using, you could box them with foam and change your lights to leds. Probably pretty safe there.





Morning Wood said:


> Make sure you use proper clearances.


Morning Wood has it correct - you still must maintain the proper clearances (generally 3" all around the box) even with LED's. One of the main reasons is that unless the box is rewired to only accept LED's the HO, or another one could incandescentcent back in. 

One catch with foam boxes is many manufacturers require a lower R-Value for the top cover which basically defeats the purpose of building them. Personally I am for no can lights

http://blog.sls-construction.com/2011/rip-recessed-lights-part-deuce
http://blog.sls-construction.com/2011/rip-recessed-light


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## Sar-Con (Jun 23, 2010)

Well, I found the cut sheet on the lights and they specify no insulation closer than 3", and no combustible material closer than 1/2". So I figure the least intrusive fix is to pre-build the boxes, leave 3" all around and seal it up, then insulation around.

Thanks for the feed back!


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## DuMass (Feb 6, 2008)

If it were me, for all the extra added expense and aggravation of installing those boxes, I would probably just replace the old RC lights with new IC/airtight remodel cans and trims and be done with it. Throw another layer of insulation in the attic space above and you’ll never even have to think about them again, until it’s time to replace a bulb anyway.


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## The_Modifier (Dec 19, 2010)

BCConstruction said:


> it's unreal how they don't get hot.


Really? :no: Why do they design them with large heat sinks then?:whistling

Not trying to pick on you, but they are design and manufacturers list that they toss out heat as well right on the packaging.

http://www.sylvania.com/BusinessProducts/Innovations/LEDLampsandRetrofits/


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## Morning Wood (Jan 12, 2008)

The real problem with the recessed lights is they have air leaks. Even the ones that aren't supposed to, I wouldn't trust them. That is why I'd build a box around them. You don't need maximum R value, but you do want them air tight.


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## smalpierre (Jan 19, 2011)

I'd just replace them with IC cans. A lot less trouble than building boxes.


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