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.

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.

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.

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.

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.

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 - Email - Maple Grove Home Inspections

    

Ice Dams, Pantyhose, Salt

Ever since I was a teenager working at a hardware store, I've heard of people filling up pantyhose with salt and tossing them on their roof to create drainage channels in ice dams.  After hearing about this so many times and even seeing this method of creating drainage channels in ice dams on the news, I began to believe this actually worked.

Nevertheless, I tend to question everything, and last year I finally got around to testing this method on my own.  Instead of laying the pantyhose perpendicular to the ice dam, I laid them parallel to the ice dam in an attempt to get rid of the ice dam entirely.  As I mentioned in my blog about how to remove ice dams, this didn't work well at all.

Several readers suggested I place the pantyhose the way everyone else does (does everyone else really do this?), perpendicular to the ice dams.  The whole idea of placing them perpendicular to the ice dams is to create drainage channels for water, so water doesn't back up in to your house.

I tried this on a cold January day at my neighbors house (thanks for being a willing participant, Jonathan).  I was also curious as to what magical properties the pantyhose possessed.  How do pantyhose make salt so much more effective than salt alone?   Wouldn't it work a lot faster to just put salt directly on to the ice dam?  As it turns out, yes.  This works way better.

The photos from my little experiment are below.  I filled one of the pantyhose up with "Ice Melt", which contained a blend of calcium chloride and rock salt.  I filled the other pantyhose with an ice melting salt that didn't have the contents labeled - I suspect it was just rock salt.  I also poured the Ice Melt in a perpendicular line along the ice dam, using far less salt than I used in either of the pantyhose.

10:00 AM (Start Time)

 

2:00 PM

 

4:00 PM

 

Hmm... it looks like we have a winner.  If you're going to put salt on your roof, I don't understand what the purpose of using pantyhose is.  The obvious thing here is that salt applied directly to an ice dam is far more effective than salt in a pantyhose.  So you can run and tell that.

Reuben Saltzman, Structure Tech Home Inspections - Email- Minneapolis Home Inspections
    

One More Ice Dam Removal Method - Blowtorch

This is a follow-up to my blog post on How To Remove Ice Dams. Several people suggested using a blowtorch, and I thought it would be easiest to just follow up with a video. Sorry for the lousy sound quality - I didn't want to use my good camera on the ladder.



Reuben Saltzman, Structure Tech Home Inspections - Email - Minneapolis Home Inspections



RELATED POST: How To Prevent Ice Dams

How To Get Rid Of Ice Dams

Last year at about this time I wrote a blog about ice dams, covering what needs to be done to prevent ice dams from happening, both on the inside and outside of the house.   This year I'll discuss a bunch of different ways to get rid of ice dams.  The methods involve axes, ice picks, pantyhose, salt, and heat cables.

Axe

The most obvious way to get rid of ice dams would be to just take a blunt instrument and hack away at the ice dams.  I tried an axe.

Pros: Fast results - I hacked through several feet of six-inch thick ice dams in a matter of minutes.
Cons: Unsafe and cumbersome.   I had a set up a ladder on the icy ground and swing an axe while standing on a ladder.  The ice also really flew in my face - I should have been wearing goggles!  I was only able to remove the ice down to the gutter, and only able to get close to the surface of the roof without risking damage to the shingles.
Verdict: This is a high risk, but fast and effective way of getting rid of a lot of ice, but leaves the job incomplete.

Ice Pick

Sounds like a natural choice, doesn't it?  I actually used my awl, but close enough.

Pros: Very fast results, very little effort.  It's as though this tool was made for picking at ice.  Oh, wait...  Still, I was genuinely surprised at how fast and accurate this method was.
Cons: Unsafe.  Again, I was jabbing at ice dams while standing on a ladder, which was sitting on the icy ground.  I also had to be very careful to not damage the roof.
Verdict: This is definitely my method of choice.  Nothing else worked nearly as well.

Roof Tablets

Yes, this is a product designed specifically for preventing damage from ice dams.  Contrary to the name on the container, the product doesn't actually melt your roof (whew).  The instructions say to toss the tablets on to your roof and they'll melt through the ice dams, allowing for "water to drain safely".



I tried tossing the tablets on the roof like the instructions said to do, but it didn't work out very well.  I consider my tablet tossing skills to be above average, but I still couldn't get the tablets to end up in a good location - they all just slid together in one place.  If I didn't get a ladder out to take pictures, I never would have known that the tablets didn't end up a good spot.

Just to give the roof melt tablets the best possible chance for success, I hand-placed them on the ice dam and I used about four times as much as the directions called for.

By day two, I had some pretty dramatic results - the tablets had melted all the way through the ice dam.  btw - for anyone in a southern climate that might be reading this blog, that white stuff on the ice is snow, from a very light snowfall the night before.

By the third day, not much change.  There were definite holes in the ice dam, and some channels had formed for water to drain through, but the majority of the ice was still there.
 
Pros: If you had perfect aim and tablets didn't move after you tossed them on to the roof, this would be very safe.
Cons: The tablets don't stay where they land, which negates the whole safety thing - I still had to set up a ladder on the icy ground and move the tablets around myself.  This method was also pretty ineffective - it created a bunch of holes in the ice dam, but so what?  Most of the ice dam was still there in the end.
Verdict: This might be a nice way to get down to the roof surface, and it would be nice to follow up with an ice pick after a day or two, but the tablets alone aren't great.  Sure, it's safe... but so is sitting inside a warm house.  Neither gets the job done.

Salt Filled Pantyhose

This is a simple, straight-forward approach.  Take off your pantyhose, fill 'em up with ice melt (calcium chloride or something similar), and toss 'em on your roof.  The idea is that the salt will leak through the pantyhose and eventually melt the ice dams away to nothing.   This is supposed to work better than just putting salt directly on the roof, because salt applied directly to the roof will just melt a bunch of tiny holes, much the same way the tablets melted large holes.

By day two, there were several tiny holes in the ice dam.  Whoop-de-doo.  Salt alone would have done this.

By day three, the pantyhose had started to melt in to the ice dam, and had completely melted down to the roof.   The part that hadn't melted down to the roof basically had a hard, crusty layer of salt(?) formed on the bottom of the pantyhose, and nothing else was happening.  I picked up the pantyhose, broke up all the chunks of stuck together salt, and placed it back down.
 
On day four, I tried moving the pantyhose again to loosen up the stuck together chunks of salt, and the pantyhose ripped apart, leaving a big mess of salt on the roof.  Yuck.


Pros: This is pretty safe.
Cons: Took way too long and didn't do much.  Waste of time.  I wonder if I can return the pantyhose to Walgreens?
Verdict: Better than nothing.

Heat Cables

For the record, heat cables aren't supposed to be placed directly on ice dams, but some people might try it anyway.  My friend did this at a house he owns in Saint Louis Park... so I took pictures.  These photos all show the heat cables after about one day.

Note the creative way of keeping the cables from touching each other.  Pretty cool, huh?



Pros: Gets the job done, and will prevent the formation of ice dams throughout the rest of the year.
Cons: Heat cables aren't made for this, and I'm sure the manufacturer would tell you that this poses some type of safety hazard.  Stringing up the cable was also very unsafe.  It's a good thing my friend owns a jet pack.
Verdict: Don't do this.

Summary

An ounce of prevention is worth a pound of cure.  My favorite method was definitely the ice pick, but this was also very unsafe, and there's a good chance that the roof surface could get damaged this way.  I'd rather not have to deal with ice dams at all.

After a good snowfall, rake the snow off your roof.   This definitely takes the least amount of effort and it's safe.  I've been asked whether a roof rake will damage the roof, and the answer is definitely no.  A good roof rake will have little wheels at the bottom of the rake , which prevents the bottom of the rake from even touching the surface of the roof.  Rake away.



Reuben Saltzman, Structure Tech Home Inspections - Email - Minneapolis Home Inspections

    


RELATED POST: How To Prevent Ice Dams