Radiant Barrier Sheathing Warning

RBS Lightning mitigation plan


Every fastener in the roof deck is a conductor into the RBS.

The “point” is that there is no evidence. The paper says so…

Did I say dismiss anything, no.

If you feel it is your job, and you think your frigging qualified, then go for it.

My point (hopefully so you can understand it) is that many things are not our responsibility and should not be considered to be.

Why the hell should a Home Inspector consider taking this on when there are so many standards that clearly dictate that it is not. When a bunch of forensic engineers can’t prove it, no one is recalling it, where is your qualification and responsibility to do so?

As I said, this is good info if you see a condition that this is happening (or hapened). You’ll be the hero you seem to want to be!

I think that the McDowell study might carry some weight in court and might influence a verdict on inspector negligence, so it seems to me that how an inspector chooses to handle this issue might be best decided by consulting with an attorney, since it’s probably going to vary by state.
How’d you find this, Frank?

Someone posted it in the Texas forum. I was interested because I have it on my house.

Good work, man!

If you think for one minute that I want to be a hero then you don’t know me very well.
You seem to just want to throw your weight around because you have a few more pieces of paper that says your qualified in something and few more years then me in this industry but that doesn’t make you more qualified as a human being, so try acting like it.

It’s pretty convincing to me. I’m not saying everyone should jump on the bandwagon, just that it seems pretty well researched and written by a qualified bunch of guys. If you’ve read this document, what will you tell your client who has hired you to protect them from any safety hazards that might be connected with this property?

I have read it, before it was posted here, and I understand the implications, but that doesn’t mean there isn’t room for levity. I also don’t think you are going to find a viable mitigation method short of removal.

I’m going to tell my clients that if your house gets struck by lighting it could very well catch fire and you might die. Studies show that newer houses burn much more rapidly than old houses, so have an exit plan. First I have to teach them to change smoke alarm batteries, about 90% of the 1 year warranty inspections I do haven’t even had the batteries changed out. Not to mention don’t block the kid’s room windows with tall headboards.

How can you assume that when (some-many) State Laws “require” stuff like this in our reports (Not that half of us pay any attention to the law…).

SOP - Standards of Practice
SOI - Scope of Inspection

With little or no consideration we just change our industry based on a white paper?

I can just see the next flood of new inspectors arriving, never reading the white paper, telling everyone with a silver roof their house will burn down if there is a lightning storm (just like the electrical panel thingy).

Add this to it; In the area of Disneyland Fla, there are 50 lightning strikes/per mile/per year (1.4 million strikes per year in Florida)!

In 54 years, there were 1.3 deaths/yr due to lightning in all of Fla. (which is the highest in the US).

There are 4,000 house fires across the US per year related to lightning.
How many have silver roofs?

Of all the electrical fires in service panels, how many are Zinsco?

How many houses burned down and injured someone (injured because I was told this is about safety) with silver roofs? How many houses are out there?

I am not insinuating the whole thing be ignored, but there is already talk about putting this in all reports and narratives have been written…

“Be the first guy on the block to break a real estate agents deal over a silver roof!”

Or is it really about safety?

If the defense attorney asked me about this on a witness stand, I’ll ask if he wants me to discuss the gossip about his wife because at this point it’s an old wives tale (until someone issues a recall).

At this point I’m sorry I posted that narrative.

I’ve been in contact with McDowell’s operations manager who tells me that there is litigation pending, they can’t say very much except that they are confident that the information they released about RBS is accurate, and that the experts to contact about any mitigation would be the manufacturers. I’m in the process of doing that now, but because of the litigation I don’t expect much.

Since this has been raised as a concern by McDowell, who seem to be very credible, seems to me that it would be reasonable to mention to a client that the McDowell study identifies RBS as a potential safety hazard while at the same time saying that nothing has been proven. And I wouldn’t make a recommendation to a client regarding RSB one way or the other at this point.

I have changed that narrative to reflect that there is only one study identifying RSB as a potential fire hazard and that nothing has been proven.

“[Radiant barrier sheathing]]The home had radiant barrier sheathing (RBS) installed as roof sheathing. RBS consists of a panel of standard roof sheathing that has aluminum foil-backed paper glued to the side that faces the attic. It’s purpose is to reflect solar energy that is typically absorbed by the home as heat, in order to reduce cooling costs. Its use has been widely encouraged as a means of reducing energy consumption.
A recent study by McDowell Engineering Inc. (a forensic engineering firm) indicated that because of its electrical characteristics, this foil material can be ignited by relatively low amperage electrical current. In addition, studies indicate that its use in a home increases the chance of the home being struck by lightning and that when struck by lightning the chance of a fire igniting in the RBS may be as great as 80%.
The information in the McDowell study has not been proven and litigation is pending.”

My point was that before being tempted to include something in an inspection report about an unproven accusation about a product like RBS, inspectors should first consult with their attorney. At the same time, a study by a reputable forensic engineering firm is way different from gossip about somebody’s wife.

Got emails out to Georgia-Pacific, Roseburg, and LP.

Great follow-up Kenton. Anxious to see what they have to say.

Frank you said you have it in your home. Do you feel it works as intended or notice any difference as I know you were a builder just was wondering your thoughts. Whats your input, I haven’t seen it around here.

I can’t compare before and after, because it’s always been this way. But it does seem a little cooler than others. Maybe it’s wishful thinking.

if you shoot the temperature on the roof (from on the roof) and then on a rafter (in the attic) what’s the difference in temperature?

Shoot a temperature of the surface of the roof tile? And then a rafter? It may be a few days before I’m home in the afternoon. So hang tight.:slight_smile:

I was hoping it was asphalt shingle. There will be less direct heat transfer with tile because of the airspaces between tile and sheathing.

No reply from the manufacturers.

I’m not sure what you’re trying to accomplish, but if your trying to see the effect of a radiant barrier, don’t shoot a rafter as it will be heated more by conduction than radiation. Radiant barrier films are fantastic conductors (both electrical and thermal).

I was thinking that it was supposed to reduce the ambient temperature of the attic.

It will, but you won’t get a good determination by measuring the temperature of a rafter and comparing that to the roof surface temp. The rafter will heat by conduction. You would need to test two similar spaces under similar conditions, one with, one without an RBS. Either measure ambient air temperature in the attic (use a calibrated thermometer/thermocouple) at multiple locations or place a known emissivity target where its primary means of heating will be via radiation, not conduction and measure that using infrared.