Reuben's Home Inspection Blog


Recessed Lights Are Evil

I love recessed lights, but even the best ones create a ridiculous amount of heat in attics, which can lead to ice dams.  Until I started performing infrared inspections in attics, I never quite grasped how much heat recessed lights contributed to attics, but now my eyes are wide open.  The main problem I find with recessed lights is that they’re not insulated well enough; on a recent home inspection in Maple Grove, I found a home with forty-six recessed lights sticking up in to the attic, along with some wicked ice dams on the roof.

A standard recessed light will stick up in to the attic about seven inches.  If an attic has fourteen inches of  loose fill fiberglass insulation, how much insulation does that leave on top of the recessed light?  Hang on, let me get my calculator…

At any rate, there’s far less insulation above recessed lights than anywhere else in the attic, and these are the areas that get the hottest, so they should really have more insulation than anywhere else in the attic.   Unfortunately, that never happens.  The combination of minimal insulation and hot light fixtures shows up clear as day using an infrared camera.

Recessed Light in attic with IR overlay

The images above show how much heat is leaking through the insulation above an IC rated, airtight recessed light with a 75-watt incandescent bulb.  IC rated means that it’s safe to have insulation directly in contact with the light, but it’s not synonymous with airtight.  You can usually tell if a recessed light is airtight just by looking inside it; if there are a bunch of holes inside the housing, it probably isn’t airtight.

Non-airtight recessed light

If you can see light pouring through on the attic side, it’s definitely not airtight.  All of these little holes in the housing are passageways for heated air to escape in to the attic; they’re called attic bypasses.

Non-airtight recessed light

Having said all this, I don’t think recessed lights are truly ‘evil’, but they sure can cause a lot of problems, and there seems to be very little understanding of this in the building trades.   Here’s what you can do to prevent problems:

If you plan to install recessed lights that are going to protrude in to your attic, make sure they’re airtight, IC-rated lights.  After the lights are installed, be sure to double down on the amount of insulation above the lights; you’re gonna need it.

If you already have airtight recessed lights in your home, you probably need way more insulation installed on top of them.  This is usually quite simple to do, but without an infrared camera, it might take a little time to locate all the lights.

If you already have non-airtight recessed lights sticking up in to your attic, don’t worry; there’s a fix for this.   Simply construct an airtight box out of rigid foam insulation, and ‘glue’ it together with spray foam.

Insulated Box

Now place this airtight box over the offending recessed light in your attic, and use a bunch more expanding foam to seal it up and make it completely airtight.   Not only will this prevent air leakage from around the light, but it will dramatically increase the insulation level above the light.  While the box pictured below is the ugliest box I’ve ever seen (I built it), it’s still very effective at preventing heat loss.

Insulated box over recessed light

If constructing and installing insulated boxes throughout your attic seems like too much work, you could always replace any standard incandescent light bulbs with compact fluorescent lights; they produce far less heat, they’re easy to install, and you’ll start saving money on your electricity bills.

Reuben Saltzman, Structure Tech Home Inspections


Comment balloon 65 commentsReuben Saltzman • February 01 2011 06:25AM


Question for you.

Which bulb generates more heat in the attic, incandescent or the new bulbs??? 

Posted by Lenn Harley, Real Estate Broker - Virginia & Maryland (Lenn Harley,, MD & VA Homes and Real Estate) over 7 years ago

Hi Lenn,  

Incandescent bulbs, by far.  I'll try to post some type of visual comparison between the two in the next week.  Thanks for reading!

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

Reuben, Something I wouldn't have thought about without your post.  Thanks for the explanation!

Posted by Liz and Bill Spear, RE/MAX Elite Warren County OH (Cincinnati/Dayton) (RE/MAX Elite 513.520.5305 over 7 years ago

Liz and Bill - this is something I wouldn't have thought nearly as much about without an IR camera.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

Hi, Reuben, recessed lighting is a dinosaur, unless we use led lighting with them we will not conserve what we need to.


Hey Lenn, with the recessed lighting, go with the LED bulbs. Nearly no heat and you have no need to protect for the "overheating of the bulbs" just a thought.

Clint McKie

Posted by Clint Mckie, Desert Sun Home, Comm. Inspection 1-575-706-5586 (Desert Sun Home, commercial Inspections) over 7 years ago

Clint - how about CFLs?  LED bulbs are cool, but they're hideously expensive.  I'd even say cost prohibitive at this point.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

The LED bulbs are a install it and forget it. With nearly unlimited life span even the CFL'S don't have.

The savings over the life of the bulb far outweighs the initial cost for the bulb.

Clint McKie

Posted by Clint Mckie, Desert Sun Home, Comm. Inspection 1-575-706-5586 (Desert Sun Home, commercial Inspections) over 7 years ago

CFLs are EVIL, but that is another post altogether!

Reubs!  LOVE the title!

My guinea pig woud love your "ugly" box!

It's interesting the stuff we learn with the camera!  The first thing I learned was just how much insulation slides down the wall!  What a revelation!

LOVE the image of the heat escaping through insulation.  And 50 degrees shows up real well with 14F right beside!  At 14F, you're having a heat wave...

It's not good to cover some lights, the older ones in particular, as they might overheat, even when the attic temps are in the 20's...

I done did suggest your post.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

Good Morning Reuben, the idea of a box constructed out of rigid foam insulation is excellent.  It would still allow easy access to the fixture from above.

Posted by Dan Edward Phillips, Humboldt and Del Norte Counties, CA (Dan Edward Phillips, Humboldt and Del Norte Counties, CA) over 7 years ago

Clint - LEDs are supposed to last forever, but I've found that's not the case.  I purchased a couple 5-watt flood lights from Costco to replace the 100-watt incandescent bulbs at one of my exterior floor lights, and 1/4 of the bulbs went bad after about a year.  

Apparently, I'm not the only one who has experienced this problem - . 

Don't get me wrong, I know you're right and I agree with you, I'm just playing the devil's advocate.  Once the price of LED bulbs comes down, I'll definitely jump on board.  I just can't afford to change everything out right now.  Have you done it?

Jay - What don't you like about CFLs, the mercury?  Yeah, just using this camera has been a fantastic learning experience.  

I''ve definitely learned much more about houses in the last two months than I can ever remember.  I haven't found insulation sliding down walls yet, but then again, I haven't been doing much with whole-house scans; it's mostly just been troubleshooting specific problems.

You're right, non-IC rated lights need a 3" air space.  Thanks for the suggestion!

Dan - It might be a bit of a pain to get through the foam, but certainly not impossible.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

Well, yes, the mercury.  But also, the light waves exacerbate neural medical issues, like Parkinson's, Alzheimer's, MS and migraines, maybe making them worse.

Also, I have an economic disagreement.  100% of our light bulb capacity is sent to China, with no comparative advantage to return anything to us.  Stupid.  99.9% of those things are made in China - again, stupid.

And you think the earth notices it when we use incandescents?  Think carefully...

Again, stupid.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

As usual, Reuben, a very informative post.  Are there guidelines for how old is too old to put the insulation boxes around or how much space one should allow?  I wouldn't want to create any fire hazards.

Posted by Peggy Chirico, REALTOR® 860-748-8900, Hartford & Tolland County Real Estate (Prudential CT Realty) over 7 years ago


This is excellent information. And, I very much appreciate the solution here too.


Posted by Brian Madigan, LL.B., Broker (RE/MAX West Realty Inc., Brokerage (Toronto)) over 7 years ago

Wow. Never even thought of this!  Thats why it was a great blog to feature.

Posted by Chuck Carstensen, Minnesota Real Estate Expert (RE/MAX Results) over 7 years ago

Very True- I turn mine off because they get so hot. 

Posted by Gerard Ladalardo (Black Ops Outfitters) over 7 years ago


Way to go, that was a great read. I love posts like that where I actually learn something.


Posted by Brent & Deb Wells, Prosper TX (LivingWell Properties) over 7 years ago

Wow, pretty interesting information.  I will be going up to my attic tomorrow to replace lights.  Thanks

Posted by Conrad Allen, Webster, Ma, Realtor (Re/Max Professional Associates) over 7 years ago


WOW!  Thanks for the information.  I will be sure to pass your blog on to my clients and inspectors when I see recessed lights in a home.

Posted by Evelyn Kennedy, Alameda, Real Estate, Alameda, CA (Alain Pinel Realtors) over 7 years ago


Great information for the homeowner.  The issue of insulation around recessed lights is important for several reasons.  When HABITEC conducts a Home Inspection in the Nashville TN area, we often see recessed lights in contact with insulation.  Those recessed lights that are not IC rated (insulation in contact) for contact with flammables such as insulation are frequently buried in insulation.  Although insulation is not highly flammable, it is still considered a flammable product and should not be in contact with recessed lights that are not IC rated. 

Thank you,

Richard Acree

HABITEC Home and Building Inspections, LLC (Nashville, TN)

Posted by Robert Dirienzo, Home Inspections - Nashville TN (HABITEC Home and Building Inspections, LLC) over 7 years ago


That was an informative post.  Really liked your post.  Thanks!

Cheers from Lake Tahoe,

~Grace Yee

Posted by Brandon & Grace Yee, Lake Tahoe Real Estate (Chase International) over 7 years ago

I just learned a whole lot about recessed lights. Cool box solution!

Posted by Cheryl Ritchie, Southern Maryland 301-980-7566 (RE/MAX Leading Edge over 7 years ago

Great info and I will bring this up to my electrician seller who has more canned lights than any home I have ever seen!

Posted by Gary & Melynda Wolter (CRS) 480-269-1164, Relentless, Reliable, Premier Personal Service (Evenson/Fisher Group-Revelation Realty) over 7 years ago

Reuben, wow...i'm putting in recessed lights in the spring & i've bookmarked this for my electrician...excellent...had no idea about IC light...what is this though about cfls & medical conditions??  One of you should do a post on that...i'm clueless on that?

Posted by Ginny Gorman, Homes for Sale in North Kingstown RI and beyond (RI Real Estate Services ~ 401-529-7849~ RI Waterfront Real Estate) over 7 years ago

That's something I had never considered.  Thanks for sharing the information.

Posted by Kristyn Grewell, Edmond, OK Homes, Oklahoma Relocation Services (CENTURY 21 Goodyear Green Edmond, OK) over 7 years ago

I love recessed lighting, it looks great and modernizes a home!

Posted by Ryan Case, 877-828-0710 (SCA Real Estate) over 7 years ago

Reuben, Thank you for the advice. Homeowners love these little tidbits and it makes us look good to have them in our information.

Posted by Pat Braithwaite, E-Pro (Braithwaite Realty) over 7 years ago

Reuben, I love the rigid foam box concept!  

Thanks for yet another useful and practical suggestion.

And ditto to what Jay said in #11 about CFLs, but that's another post for another time.

Posted by Fred Griffin, Licensed Florida Real Estate Broker (Fred Griffin Real Estate) over 7 years ago

When incandescent bulbs become but a dim memory, so goes this issue!

Posted by Richard Strahm, Lansdale and North Penn Real Estate (American Foursquare Realty) over 7 years ago

Thanks for posting this useful information.  It was a real eye opener.  I'm just getting ready to install recessed lights in my 60's ranch home.  Will keep this in mind.

Posted by Joye Hollis Ridgeway, - Homes, Land, Investment, Commercial (AgentOwned Realty, Charleston SC) over 7 years ago

Very intersting.  I was not aware of this.... I am glad we have switched to the energy saving lights

Posted by Joan Whitebook, Consumer Focused Real Estate Services (BHG The Masiello Group) over 7 years ago

How come no inspectors in my area are using IR cameras!  Arrrgh!

Posted by Ed Urbaniak (The Chin Sells Team at Weichert Realtors) over 7 years ago

Same as Ed said, "How come no inspectors in my area are using IR cameras!  Arrrgh!"

Without giving away any trade secrets, how much does a camera cost and how much training do you need? It is obviously a valuable tool. I got to get someone down here in Wisconsin to start offering the service. Thanks, Reuben 

Posted by Fred Hookham (Keller Williams) over 7 years ago

Interesting post and comments. I am learning a lot here. THanks!

Posted by Kristi DeFazio, Colorado Springs Rea lEstate 719-459-5468 (RE/MAX Advantage) over 7 years ago

Hi Reuben~  Oh Great!  We are building a living quarters at our farm and have put in a lot of recessed lights.  My husband is going to love this post! 

Posted by Vickie McCartney, Broker, Real Estate Agent Owensboro KY (Maverick Realty) over 7 years ago

Reuben, I have always wondered if the old recessed housings could be insulated in some way.  You have answered my question.  In Texas, the old housings create drafts in the winter and heat in the summer from the incandescent lamps and the gaps in the housing.  Have you ever thought about using the Styrofoam rose cones that garden companies make to protect rose bushes in the winter?

Posted by Sharon Parisi, Dallas Homes (United Real Estate Dallas ) over 7 years ago

Interesting information.  I never knew that recessed lights put that much heat in the attic.  I don't know what the heck an ice dam is because I've lived my entire life in the Phoenix area but it doesn't sound good.

Posted by Carla Morin (Brookfield) over 7 years ago

Hi Reuben,

Great stuff,

every year there are still a number of house fires started due to porly installed pot lights, so anything to lower the temp is a good thing.


Posted by Peter Pfann @ eXp Realty Pfanntastic Properties in Victoria, Since 1986., Talk To or Text Peter 250-213-9490 (eXp Realty, Victoria BC over 7 years ago

Great info! I can't use the CFL's in my home because they give me headaches. I agree the LED's are rediculously expensive and I read the hours of use and they aren't much different then the CFL's so why pay 3x the price. I don't know. I hear the incandescent bulbs are going away soon. I must stock up or I will have to live in the dark.

Posted by Stacia Whatley, StaciaSellsHomes Your Western WA Realtor® (Hawkins-Poe Inc.) over 7 years ago

Reuben these things are like little chimneys.  Part of the problem is that they stick up about 8-10 inches so with even the ones that can be buried you might end up with only a couple of inches on top of them---they need the same amout or more over them as in the rest of the attic.  Frankly it would be a lot better to just not use cans wherever insulation is necessary.

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) over 7 years ago

Great informational article and discussion.  I would never have thought of this.  Margaret C.

Posted by Margaret C. Taylor, St Marys/Calvert/Charles MD Real Estate Agent (Century 21 New Millennium MD) over 7 years ago

I am not a fan of recessed lighting. Never have been, for the simple fact they do "let the heat out".

And Rueben is right about the LED's not lasting for ever, but they are a very good alternative to the conventional and cfl lighting available today. 

Posted by Clint Mckie, Desert Sun Home, Comm. Inspection 1-575-706-5586 (Desert Sun Home, commercial Inspections) over 7 years ago

What an excellent post.. happy to have landed here. . I learned a lot

Thanks for writing it!

Posted by Fernando Herboso - Broker for Maxus Realty Group, 301-246-0001 Serving Maryland, DC and Northern VA (Maxus Realty Group - Broker 301-246-0001) over 7 years ago

What an excellent post.. happy to have landed here. . I learned a lot

Thanks for writing it!

Posted by Fernando Herboso - Broker for Maxus Realty Group, 301-246-0001 Serving Maryland, DC and Northern VA (Maxus Realty Group - Broker 301-246-0001) over 7 years ago

Being a Florida Home Inspector I always for get about the Northern winters. We don't get any snow, nor have a ever even seen an ice dam on a roof, however, I remember it from my training and this seems like a good fix.

Posted by A1 Certified Home Inspections over 7 years ago

Reuben, a very good informative post. Something most people don't think about.

Posted by Michael Setunsky, Your Commercial Real Estate Link to Northern VA over 7 years ago

We have recessed lights and I never knew this!  I will be sending my husband up in the attic to take a look at them & see if they need insulation.  (He will be thrilled I am sure!!) Ironically, the room with the recessed lights is also in the part of the house that gets the least amount of sun.  So the sun doesn't  hit the gutters as much & that's where the ice dams are.  I assumed it was the sun....never thought about the recessed lights.

Posted by Christine Smith, Exclusive Buyer Agent & Attorney, Canton, MA (Buyers Brokers Only LLC - over 7 years ago

Great post and thanks for sharing a solution. Now I guess I'll have to crawl around in the attic.

Posted by Ryan Dressel, Sacramento Home Staging (Stage Right Design, Inc.) over 7 years ago

Wow! Great information. I wasn't aware of that and will make note on an upcoming renovation.

Posted by Tom Robinson, Experienced Real Estate, Professional Serving No. VA and DC (Keller Williams Realty Kingstowne/Alexandria, VA Office) over 7 years ago

Great post.  I like your solution in the attic.  I agree with you about the LED bulbs that they are high in price. However,yesterday I was in Home Depot and they are coming down in price.  Give them a couple of years and they will be reasonablely priced.

Posted by Keith Lawrence, ABR, CDPE, SFR, 203K Specialist (RE/MAX Properties) over 7 years ago

Very good stuff, Reuben. Will be reblogging once I get back to the office. Great photographs too...

Posted by Aaron Seekford, Ranked Top 1% Nationwide 703-836-6116 (Arlington Realty, Inc.) over 7 years ago

Great information Reuben. I am planning to install recess in my home and I will keep your blog in mind.

Posted by Ritu Desai, Virginia Realtor-Fairfax/Loudoun/PW-703-625-4949 (Samson Properties) over 7 years ago

In the winter, can feel the cold coming from the attic through the lights into the home. The foam box would be a great way to stop that.

Posted by Michael Simcock, Elk Grove, CA Realtor 916 425-1084 (Coldwell Banker (Elk Grove, CA)) over 7 years ago

Great information, and I have often wondered about that.  I have the big boxy ones with long fluorescents in my kitchen and have been planning to take them out.  During hurricane Ike, insulation blew into them from the wind that it made it's way into my attic.  That was a good clue that I needed to change them out, but they are also dated.  An upgrade is in order.

Posted by Kate McQueen, Tailored service for your real estate needs! (CB&A Realtors) over 7 years ago

Thanks for the information, Reuben.  I think the ultimate solution is definitely LED bulbs.  The price has come way down on them, LED bulbs can now be had for about $6-$10 each for this purpose,  use 5 or 6 watts of electricity and really work well for this kind of application.  CFLs can still cost this much if not bought in a multi-pack.

Posted by Bill Rozek, NMLS #214260 (Embrace Home Loans, Inc.) over 7 years ago

Good idea about installing the foam box over the lighting to prevent heat escape and allow easy access.

Posted by Joyce Herr, Lancaster County & Beyond (Prudential Lancaster Real Estate) over 7 years ago

Thanks for the comments, all!  I can't respond to everyone, but I'll try to get back to everyone who had follow-up questions.

Jay - I had no idea about all of those medical conditions created by CFLs.  I suppose it's the same for standard FLs too?

Peggy - great question.  Yes, there are rules as to how close insulation can come to the older, Non-IC rated lights.  If recessed light is not IC-rated, you should usually maintain at least 3" of clearance around the light. 

Ginny - I'm also quite clueless about any medical conditions related to CFLs.  I see a follow-up post on this topic in Jay's future...

Ed - as the prices of IR cameras continues to go down, you'll start seeing them in your area.

Fred - I was going to say that the cheapest, worst camera available is selling for $2500 new, but it looks like there's a new, even cheaper one selling for $1200 today at .   The price goes up from there.  The 'formal' training typically takes about 24 hours or so, but it takes a lot of practice before you can really understand what you're seeing.

Sharon - I've never considered the foam rose cones, but that sounds like a fantastic idea.  I'll have to try that next.

Charles - and that's without the lights on.

Bill - I haven't been able to find any LEDs for nearly that cheap.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

Try .  They are a company out of Hong Kong that my assistant has used for several purchases.  He says shipping is usually free or about the cost of a postage stamp.

Posted by Bill Rozek, NMLS #214260 (Embrace Home Loans, Inc.) over 7 years ago

Reuben - Thank you for such a wonderfully informative post.  I saw it this morning and didn't have time to comment.  So glad I found it again.  The comments have really added to the post! 
Go Active Rain!

Posted by Christine McDaniel, Broker Associate (Coldwell Banker Residential Brokerage Porter Co.) over 7 years ago

I don't know.  But I have posted stuff about CFL's before and nobody cared!  So what did I do?  Hoarded incandescents!  All sizes!  I have enough for the next century!

The gubment has no more authority to tell me which light bulbs to buy (and to prevent me from buying certain ones) than they do to tell me that I have to eat Twinkies for breakfast or that I MUST buy their health "care."

But that is just me...

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

Hi Reuben, great information.  The design concept with foam insulation and a sealed attic space will avoid the heat loss and ice dam issue for many spaces.  Great for new construction, but does not help the existing homes.  Your box solution is clever.

Posted by Dale Ganfield over 7 years ago

When I do an energy audit I have standard language in the report that explains about placing insulated boxes over recessed lights.

Posted by James Quarello, Connecticut Home Inspector (JRV Home Inspection Services, LLC) over 7 years ago

Bill - I checked it out, thanks for the link.

Christine - thanks!

Jay - what about paying taxes?

Dale - thanks.  Every box I've ever seen looked a lot better than mine, but it's still quite effective.

James - great idea.  I haven't done any energy audits, nor have I had any type of training on doing them.  Maybe some day in the far future...  if I do, I'll be sure to chat with you first.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

Reuben, this is very informative post, as I did not know recessed lighting can cause problems in the attic. I also agree with Jay #11 comment about cfls.

Posted by Pamela Seley, Residential Real Estate Agent serving SW RivCo CA (West Coast Realty Division) over 6 years ago

Reuben great post and comments that follow, thanks for the information.

Posted by David Popoff, Realtor®,SRS, Green ~ Fairfield County, Ct (DMK Real Estate ) over 6 years ago

Pamela - thanks.  You probably don't have nearly as much to worry about in your climate.

David - thanks for reading! 

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 6 years ago