Thread: IC Light and Browning of Blown Insulation

I have notice that a few IC rated lights have caused a "Browning" or deep "Darkening" of the cellulose blown in insulation. Has anyone noticed this before and what is the cause/fix for this? Anyone ever known of this being a fire hazard? The house and insulation in question is about 12 years old.

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I can see that happening.

The IC lights (many of them, especially the older ones were TC - thermocouple protected) simply have a bi metal strip which opens when the light gets too hot. That shuts the lamp off, allows it to cool down, then the bi metal strip clicks back on and the lamp comes back on.

With that cycling action, the recessed light heat up, cools down, heats back up, etc., and the insulation next to the light would do the same.

Some newer IC recessed lights have a larger can around the smaller interior light, this creates an air space and some do not have the TC, others still do, but it only acts as a safety shut off if it gets too hot inside the outer can. In fact, maybe all the newer IC lights have the TC for overheating protection now?

Thanks Jerry,

I was a little concerned that the browning looked to me somewhat like how paper will smolder before ignition, it was only around a few of the light and I thought maybe bulbs with higher than recommended wattage had been used prior. I didn't know if anyone had ever seen this cause a fire before or if it was typical of aging insulation against a IC light.

Thanks

Robert,

Originally Posted by Robert DeVaney

I didn't know if anyone had ever seen this cause a fire before

It "could" cause a fire, but then lots of things "could" cause a fire , but I doubt it would cause a fire.

or if it was typical of aging insulation against a IC light.

I would say it would be typical of most things which are close to a recessed light fixture as the recessed light fixture housing do get quite warm ('hot' even), which is why the old, non-IC recessed lights caused (were at least blamed for starting) fires. That is what lead to the development of the IC light - to make it safer regarding heat-wise and not get hot enough to cause a fire.

"Can" things fail? Sure, anything and everything "can" fail, and that includes the TC (thermocouple) in IC lights.

Is it worth pointing out and putting in the report? Yes, you are describing what you saw, and noting that the lights were IC rated (if the lights were IC rated), and if not IC rated, then, yes, that could become a real problem. Either way, you are putting it down, and when your client goes to sell and their buyers' home inspector reports it, well, so did you.

Is it bad? You don't know, but this is what you saw and it is in the report.

When someone would ask me about cellulose insulation I would say that all it is is chopped of newspaper with a fire retardant chemical added, and that I had no idea how long it would last, but that people a lot smarter than me ran tests on it and decided it was "safe enough" to put in attics where it would remain until the house burned down ... er ... ... for as long as the house was there.

I have seen the heated look to insulation around these lights. Recommended or not I mention it to the clients for a possible fix like the fix for the no contact lights. Aluminum flashing roll cut to length to surround the lights and then tuck the insulation back in.

As Jerry said. It could possibly fail to the point of causing a fire but it is doubtful but I add my n otes to the report for the clients sake. I may tick off a Realtor or 2 but hey, they are my clients and I am looking out for them. I recommend it as more of an upgrade for safeties sake.

Thank you both Jerry and Ted,

Your comments were very close to my thinking, I was just wanting and got the second opinion I needed. Thanks for the input it has been very helpful and I thank you for taking the time to give your point of view.

Originally Posted by Robert DeVaney

I have notice that a few IC rated lights have caused a "Browning" or deep "Darkening" of the cellulose blown in insulation. Has anyone noticed this before and what is the cause/fix for this? Anyone ever known of this being a fire hazard? The house and insulation in question is about 12 years old.

Another possibility may be caused by simple air flow / filtration (stack effect) if this area is not tightly sealed.

Originally Posted by Joe Klampfer

Another possibility may be caused by simple air flow / filtration (stack effect) if this area is not tightly sealed.

Right. Something like this? Mouldy dust. The mold won't grow on the underlying fiberglass, just on the surface.
If it's a burn, it will be darker when you dig down, never seen that.

You should try to distinguish between actual 'charred' cellulose versus stained from particulates. One way to do this is to see if you have incidental contact marks on the side of the can where fibers actually stick to the metal. This is usually from heat but esp. with fiberglass resins.

If you see white deposits on the metal next to brown staining that is probably the borax or phosphate fire retardant/ bug deterrent leaching out leaving the cellulose unprotected and charring. White powder should not be confused with borax as this is usually a sign of someone dusting off with baby powder in the shower. I've taken lab samples and proven this in an insurance case before.

JP, those were bimetal snap discs--not thermocouples but same theory. Homeowners would put 100 watt bulbs in then complain when those cheap fixtures would shut off intermittently, when they were actually doing their jobs.

Non-IC cans as well as non-ICAT cans both leak air. This air will carry indoor air full of pollutants through gaps in and around the can into the attic insulation where it gets filtered. This presents as staining. ICATs properly installed should not suffer this phenomenon.

To recap a previous discussion: you can NOT place boxes or covers over non-IC cans as it is a fire hazard. Even the IRC code commentary showed it wrong. These cans must breathe to strip heat away. You can box over an IC rated can. Insulation dams placed around non-IC cans are acceptable except I would be advising homeowners to replace all non-ICAT cans regardless. Cheap insurance and it improves the weatherization of the home, which not only saves money but makes atmospherically vented appliances more resistant to spillage and backdrafting.

Originally Posted by Bob Harper

JP, those were bimetal snap discs--not thermocouples but same theory.

True, but that was why they were called TC, which stood for TC protected.

When IC recessed light fixtures first came out (early to mid 1970s as I recall), that was the protection which was offered by many brands, some came with large 'boxes' around them to achieve the IC rating, now, though, the IC ratings are based on other than the TC.

Here is an example of a current manufacturer offering two different models, with different physical configurations for IC and TC and for the lamp wattage size: http://www.junolightinggroup.com/productguide/124.pdf

A lot of changes have taken place in the past 40 years regarding lighting and lighting fixtures.