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Window Reflections Can Melt Vinyl Siding

Siding and window manufacturers are reluctant to discuss the problem

Posted on Aug 27 2010 by Martin Holladay

UPDATED September 3, 2013

In almost every corner of the U.S., reports are increasing of vinylCommon term for polyvinyl chloride (PVC). In chemistry, vinyl refers to a carbon-and-hydrogen group (H2C=CH–) that attaches to another functional group, such as chlorine (vinyl chloride) or acetate (vinyl acetate). siding that has been melted by sunlight bouncing off nearby windows. This melted-siding pandemic makes vinyl manufacturers very nervous — so nervous that the topic is rarely discussed.

Most reported cases involve siding that melts, gets replaced, and then melts a second time. One possible reason for the apparent increase in cases of melted siding is the increasing use of high-performance glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill..

Not our problem, says Pulte

Arlene Taraschi, a homeowner in Delanco, New Jersey, described her melted siding in a letter to a Q-and-A column in the Philadelphia Inquirer: “Two years ago, my husband and I purchased a new, Pulte-built home in South Jersey. After a few months we noticed the vinyl siding on one side of the house seemed to be dented in a diagonal pattern. The siding contractor replaced the siding on the entire side of the house. This was done last January, and by February the denting pattern began again. We were told at this time that it was because of the reflection of the sun’s rays from our neighbor’s house. Pulte has termed this melting of the siding ‘thermal distortion,’ and refuses to correct the problem.”

As Taraschi’s case makes clear, these cases aren’t just public relations nightmares — they’re legal nightmares. Arlene’s husband, Carl Taraschi, told me, “I’ve sued Pulte, the siding installer, and the siding manufacturer.”

Since 2007, when I first reported on cases of siding melted by window reflections, I’ve collected homeowner reports of the phenomenon from 16 states (Connecticut, Georgia, Florida, Illinois, Iowa, Maine, Massachusetts, Michigan, Minnesota, New Jersey, North Carolina, Ohio, Oregon, Pennsylvania, South Carolina, and Washington).

Danny Winters works for Cimarron Homes, a builder in Durham, North Carolina. Winters told me, “I think it is a common problem. We are looking for solutions. At one of our houses, the reflection hits the home next door. These are south or southwest facing windows. Whenever I’ve seen the problem, without fail, the melted siding makes a diagonal pattern, starting high and coming across in a downward motion. If you look in communities with a lot of vinyl siding, with houses on relatively small lots, you’ll see that pattern.”

A television news report on the phenomenon from a Boston-area TV station has been posted on YouTube.

Siding warranties won’t cover the damage

According to Dave Johnston, the technical director for the Vinyl Siding Institute, the phenomenon is rare. He noted, however, that “most [vinyl siding] manufacturers have had to deal with the issue.”


CertainTeed vinyl siding: “This warranty does not apply to … vinyl siding products which have been distorted or melted due to an external heat source (including, but not limited to a barbecue grill, fire, or reflection from windows, doors, or other objects).”

Heartland vinyl siding: “Heartland is not liable for conditions or failure of or damage to such products resulting from … distortion or warping due to unusual heat sources (including outdoor grills and reflection from windows or foil sheathing) …”

Mastic vinyl siding: “This Warranty does not cover … warping or distortion due to exposure to excessive heat sources (e.g., barbecue grills) or exposure to unusual or excessive reflective heat sources (e.g., window reflection).”

Vytec vinyl siding: “This warranty covers only manufacturing defects in Vytec Products manufactured by Vytec. All other causes of material failure, including … vinyl siding products which have been distorted or melted due to an external heat source (including, but not limited to a barbecue grill, fire, or reflection from windows, doors, or other objects) …. are excluded from this warranty.”

One striking piece of evidence that such problems are not as rare as industry representatives maintain is the fact that all major manufacturers of vinyl siding have now changed their warranties to exclude damage caused by window reflection (see the accompanying sidebar, “Vinyl Siding Warranty Exclusions”).

Vinyl has a low melting point

According to a statement released by the Vinyl Siding Institute, “The typical heat distortion [melting] temperature of vinyl siding is approximately 160 to 165 degrees Fahrenheit. When temperatures reach these levels, the siding could distort.”

Michael Bitterice, Albert Lutz Jr., and William Siskos — three engineers employed by glass manufacturer PPG Industries — wrote an article on the phenomenon for the February 2004 issue of Window and Door magazine. The authors reported that dark-colored vinyl siding, if installed in a location where it receives reflected light from a window, can reach 219°F.

According to Mark Haupt, a homeowner in Winston-Salem, North Carolina, sunlight bouncing off a window is hot enough to burn his fingers. Haupt posted this message on a Web forum: “The vinyl on the chimney [chase] … is melting. …This past weekend I was outside at high noon. It was a bright and sunny day. What I saw was the sun reflecting off the window putting a line of high heat — sunlight — about 1 inch wide and about 3 feet long, the length of the melted siding. I could put a finger on the siding and hold it there for less than 5 seconds; it was that hot.”

Is high-performance glass to blame?

Glass experts and home inspectors agree on one point: since vinyl siding can be melted by reflectance from conventional clear glass, a low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor. window is not required. Leslie VanAlstine, a home inspector in Dewitt, Michigan, told me that he has seen four examples of melted vinyl siding due to window reflectance; three of the homes had low-e windows, while the fourth had windows with conventional clear glass.

However, the use of low-e (or low-solar-gain) glass appears to increase the risk of melted siding. According to an article in the March 2007 issue of USGlass Magazine, “A study performed by Cardinal on this topic examined the impact of reflective coatings on this type of [vinyl siding] damage. ‘The more reflective coatings that are out there today, that are getting more popular, are going to create this problem,’ [Jeff Haberer] said. However, Cardinal found that even clear glass can become a significant heat source.”

Glass with a low solar heat-gain coefficient has a high solar reflectance. “What we are getting is very, very good windows,” said Jim Petersen, the director of R&D at Pulte Homes. “Now the energy that is not getting in the house has to go somewhere, and it’s being reflected.”

Collapsed glass

When an insulated glazing unit becomes slightly concave — a phenomenon called “glass deflection” or “collapsed glass” — reflected sunlight can be concentrated. According to Bob Spindler, the vice president of technical services at Cardinal IG, glass manufacturers are aware of the concavity problem but find it hard to eliminate. “The glass manufacturers make IG [insulated glazing] units parallel or as close to parallel as possible,” Spindler told me. “But because of barometric pressure and temperature differences, the space between the panes can become negative.”

According to Tim Singel, a marketing representative at Guardian Glass, there is no simple cure for the problem of vinyl siding melted by glass reflectance. “The issue you are describing is fairly complex, having to do with geometry and building materials as well as orientation to sun, wind and shading,” Singel told me. “There have been circumstances over the years where glass and siding have both been replaced to no avail.”

It’s not a window issue, say window manufacturers

Most representatives from window manufacturers are reluctant to talk about melted vinyl siding and glass reflectance. Cameron Snyder, a public relations representative for Andersen Windows, told me, “I have heard nothing like that reported about our products.” When I called again and mentioned Kevin Kelly, a homeowner in Parlin, New Jersey, whose vinyl siding was melted by an Andersen window, Snyder said he’d look into it. Later, Snyder provided a few brief comments. “It is handled on a case-by-case basis,” he said. “This is a glass issue, not a window issue, and it is an issue that happens very infrequently.”

Jim Krahn, the manager for advanced research at Marvin Windows, was more forthcoming. “This is something that we have been aware of in excess of ten years,” said Krahn. “If we start with too many recommendations for solutions, then we might be held responsible. We’ll leave it between the vinyl siding people and the glass people to resolve it.”

Our siding is not defective, say vinyl manufacturers

Among the manufacturers of vinyl siding that have tried to resolve cases of siding melted by window reflections are Alcoa Home Exteriors, CertainTeed, Heartland, Louisiana-Pacific, and Owens Corning.

In Alcoa’s “Field Guidelines For Warranty Claims,” the siding manufacturer notes, “Alcoa … siding will withstand all naturally occurring temperature spikes. Melting will only occur when a window reflection, gas or charcoal grill, or other heating device significantly raises the temperature.” When I contacted several representatives of vinyl siding manufacturers, they all agreed on one point: melting vinyl siding does not represent a manufacturing defect. “Thermal deformation can happen when windows are at an angle to the siding,” Jim Worden, head of Issues Management Communications for Owens Corning, told me. “The siding can actually deform. In the industry, this is not considered a product defect.”

Vinyl siding manufacturers are known to interpret their warranties narrowly; several homeowners have posted messages on Web forums complaining that siding manufacturers ignore complaints about siding melted by window reflections.

According to a recent Journal of Light Construction article on the melted-vinyl phenomenon, the Vinyl Siding Institute hints “that manufacturers are working on improvements to vinyl siding that would raise its melting point beyond 200°F, but these are still in the development stage.”

A glass problem or a siding problem?

According to window manufacturers, the high temperatures caused by window reflectance represent an unusual condition that no siding product can be expected to withstand. On the other hand, some homeowners maintain that window reflectance is a normal condition, so any siding that melts under reflected glare is defective.

These opposing perspectives are cited when different product manufacturers blame each other for melted vinyl siding. As one anonymous Web poster noted, “The siding representative is blaming the window manufacturer, the window manufacturer is blaming the siding manufacturer, and they are both blaming the building designer for placing the window too close to the corner.”

Plant a bush?

Even when manufacturers or builders are willing to step up to the plate, solutions remain elusive. While some builders may decide to switch to fiber-cement siding or brick veneer, the substitution is costly. The Vinyl Siding Institute suggests three possible solutions: planting a large bush or tree to block the reflection; installing an awning to shade the window; or installing a window screen.

“What we generally do, when people have this situation, is to suggest four or five ways to resolve it — for example, blinds on the window, or plantings like bushes,” said Owens Corning representative Jim Worden. “In some cases we have been replacing the siding, with the provision that they take certain precautions to avoid a recurrence. But no matter what you do, some folks won’t be happy.”

One possible problem with the "plant a bush" solution: there are reports that window reflections can burn plants.

Not just vinyl siding

In addition to melting vinyl siding, window reflectance has reportedly damaged other products, including garbage bags, plastic solar collectors, composite (plastic) deck boards, housewrap that hasn’t yet been covered with siding, and plastic rear-view mirrors on vehicles.

Sunlight reflecting off the windows at a new high-rise hotel in Las Vegas has not only melted plastic garbage bags; it has reportedly caused severe burns to hotel guests sunbathing beside the hotel pool. Now that's a litigation nightmare!

Similarly, in 2013 the windows on a curved skyscraper in London reportedly melted the rear-view mirror and some plastic panels on a parked Jaguar automobile. (In addition to the previous link, check out the following BBC News story: "How does a skyscraper melt a car?")

Perhaps the most alarming cases of glass reflectance are those involving the ignition of cedar wall shingles. According to the U.S. Consumer Product Safety Commission, reflections from sunroom roofs have caused four house fires. The commission has issued an alert that states, “Sunlight reflecting off of certain sunroom roof glass and skylights onto adjacent cedar shingles or cedar shakes could pose a fire hazard. … Cardinal IG and Four Seasons [a manufacturer of sunroom components] are aware of four fires that could be attributed to this scenario. There are no reported injuries. The damage ranged from minor damage to shingles and underlying sheathing to incidents that caused some structural damage to roofs and walls. … Cardinal IG and Four Seasons working together will repair the roof glass through installation of a capillaryForces that lift water or pull it through porous materials, such as concrete. The tendency of a material to wick water due to the surface tension of the water molecules. tube.”

When I contacted Cardinal representative Bob Spindler to learn more about the recall, he was tight-lipped. “Four Seasons is a customer of ours, and what happened in that case is between Four Seasons and Cardinal,” said Spindler. “There are some things that shouldn’t be published. There are certain things that from a political standpoint one can’t comment on.”

A growing problem?

Getting a handle on this problem is made difficult by the fact that data on these incidents are closely held by window manufacturers and the vinyl siding industry. While at least two organizations — the Vinyl Siding Institute and the American Architectural Manufacturers Association (an association of window manufacturers) — have arranged for research on the topic, neither organization made their data public. According to Jery Huntley, the president of the Vinyl Siding Institute (VSI), "VSI would be willing to release the information from the research, as we think it sheds light on the circumstances causing the problem. However, we are contractually prohibited from doing so without the consent of all parties, which has not been forthcoming."

The problem of melted vinyl siding due to glass reflectance shows no signs of going away. “As we build more energy efficient houses with better windows, reflected energy will be a bigger and bigger challenge,” Jim Petersen told me. Petersen’s point was echoed by Danny Winters, who predicted, “With low-e windows now being required by code, there will be a lot more people with these problems.”

Last week’s blog: “Ten Green Building Myths.”

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Image Credits:

  1. Robb Kowalik
  2. Tim Maxwell
  3. Joe Perry
  4. Clay Shaw
  5. TomC

Aug 27, 2010 7:29 AM ET

Update from a homeowner
by Martin Holladay

This morning I received an e-mail from a homeowner who read this blog and provided an update on her own vinyl siding problems. Joanne from North Carolina wrote:

"As of May, 2010 we finally have our house looking good again. At our own expense and with the approval of both adjacent homeowners, we paid to have the problem, high-E [I think she means low-e] windows replaced in the homes that are on both the east and the west side of our house.

"The windows were replaced in December, 2009, and we waited a few months to see if the reflection problem had been solved. I believe most of the damage is done in the winter when the siding is cold and the reflection from the windows on the siding makes a huge difference in siding surface temperature. Then in May, 2010 we hired a vinyl siding contractor to replace the vinyl siding on the east and west of our own home. The siding job was finished in May, 2010 and still looks good.

"It ended up costing a few thousand dollars, but we felt we had no choice. Our option would have been to re-side the entire house with a siding product like HardiPlank (which would have been even more costly)."

Aug 27, 2010 7:39 AM ET

The Article
by John Nicholas

Thank You for some interesting information. The coverage looks balanced. It certainly is informative. As a Certified HERS Rater, I am sure that I will hear about local events.

Perhaps an cheaper solution would be to install a solar screen on the windows in question. A 10 ft x 3.5 ft picture window would cost $25.00. The installation about 5 minutes with the use of 10 screws. Easily done for most Home Owners. Bonus is additional SHG is kept out of the house.

Aug 27, 2010 8:00 AM ET

Response to John Nicholas
by Martin Holladay

As I'm sure you know, these cases usually involve negotiations with neighbors. In such cases, the window owner usually experiences no problems.

While some homeowners don't mind changing the appearance of their windows to help out their neighbors, others balk. "If my neighbor chose to install a siding with a melting point of 165°F, why is that my problem?"

Moreover, your solution lowers the solar heat gain through the window. While this will probably be seen as a benefit to a Florida homeowner, it would definitely be a disadvantage for a homeowner from Maine or Minnesota, where solar heat gain through windows is desirable.

Your solution means money out of the pocket for northern homeowners, who will see their heating bills rise after the solar screens are installed.

Aug 27, 2010 8:27 AM ET

Another update
by Martin Holladay

Another homeowner who read this blog sent me an e-mail with an update. This Massachusetts homeowner asked to be identified as RB. She wrote:

"The insurance company ended up hiring an engineering firm to do a site survey and they confirmed it was the windows. So I replaced the siding, for a second time, and then the insurance company went after the [neighboring] homeowner personally from what I understand. The window company even admitted that their windows caused the melting. It was an odd claim and everyone in the beginning laughed at me but in the end, I was able to prove it.

"The article was very interesting but the one thing that I question is whether the rays being reflected contributed to my cataracts. At age 37, I developed severe cataracts which was unexplained but my office and desk sit right in front of that window where the siding was damaged. Just makes me wonder now if there is any correlation.

"I think the insurance company went after the homeowner personally because I sued her in small claims court, not expecting to win, but to simply establish knowledge and document her and her insurance company’s refusal to do anything. Cardinal [Glass] was pretty good and was willing to install the screens on ALL her windows, not just the ones affecting my siding. In all fairness, Cardinal tried to work with the homeowner who consistently refused and contributed to the problem as well as the delay in its resolution."

Aug 27, 2010 10:06 AM ET

The sad part
by David Meiland

The sad part is that Pulte's siding installer was named in the Taraschis' lawsuit.

Aug 27, 2010 10:12 AM ET

Response to David
by Martin Holladay

Contractors face a tremendous amount of liability. Now that I'm no longer building houses, I look back with wonder and amazement at the fact that so many contractors accept so much liability for such small wages or profits.

When a builder accepts a contract to install siding on a house, that contractor is in effect telling the homeowner that the installed product is suitable for use on houses.

Later, the product melts. According to the neighbor's lawyer, window reflections are a common fact, and any siding should be able to withstand normal temperatures, including the temperatures that occur when reflections hit the side of a house.

I'm not sure what the lessons are here. One possible lesson is that siding that melts at 165 degrees F may be a risky siding to install. Contractors may want to think about that when they give advice to homeowners.

If the fact that vinyl siding melts so easily makes you nervous, maybe you shouldn't install vinyl siding.

Aug 27, 2010 10:12 AM ET

Vicat softening temperature of PVC
by Doug McEvers

I would also think twice about using foil face foam sheathings directly under vinyl siding.

Aug 27, 2010 10:18 AM ET

Response to Doug McEvers
by Martin Holladay

There is absolutely no evidence that foil-faced foam sheathings cause any problems behind vinyl siding. After all, the foil facing is always in the shade!

The only problem with foil-faced foam sheathing might happen when your NEIGHBORS install it on the wall of a house under construction, causing reflections to hit your vinyl siding.

Aug 27, 2010 10:21 AM ET

Pigments in the vinyl
by Kevin Dickson, MSME

Does this warping ever happen with pure white siding?

Vinyl siding is sold as zero maintenance. In the Southwest, it needs replacing at 10-15 years, unless it's white. All the other colors seem to cause waviness in the intense sun (except on the north side of the house) The white stuff also gets very brittle after all that sunbaking. Granted, these are just field observations, but I would never buy vinyl in a sunny climate, period.

Aug 27, 2010 12:16 PM ET

A comment from Jim Katen
by Martin Holladay

[Jim Katen, a home inspector in Gaston, Oregon, sent me an e-mail, which I'm posting with his permission:]

Thanks for the updated article, Martin. I’ve been seeing this more & more. Sometimes the distortion is very subtle, but once you become alert to it the pattern is unmistakable.

Another interesting aspect: In the small farming community that I live in, the fire department seems to be aware of this issue. They think that reflections from concave windows have been responsible for grass fires here. I wonder how Cardinal would react to that news?

- Jim Katen

Aug 27, 2010 12:22 PM ET

Article in Windows and Door Magazine
by Robb Kowalik

Thanks for the update Martin. I am still dealing with my melted siding. I have been dealing wih the attorney for the manufacturer and continue to talk with professionals and gather information about this phenomenom.
I am interested in reading the article you mentioned from Windows and Door Magazine in 2004. I cannot find it and would appreciate if you could forward the information to me.
Finally, I am curious as to the warranties interpretation by attorneys and/or judges. I know manufacturer's are updating their warranties to specifically mention "heat distortion" from windows in their "Limitations" section. My warranty however, did not mention "heat distortion" in this section and I noticed their website now specifically mentions this in their warranties. If anyone has any feedback on this, please let me know.

Aug 27, 2010 12:30 PM ET

Response to Robb Kowalik
by Martin Holladay

Robb Kowalik,
Here's link to the article in the 2004 issue of Window and Door magazine:

The relevant paragraph is near the bottom of the page:
“A glass-reflectance task group met for the second time to once again review the emerging phenomenon in which sun rays reflected off low-emissivity windows generate enough heat to distort vinyl siding on an adjacent house. … More research is necessary, the group concluded, to determine worst-case scenarios and potential solutions. ‘Low-e is not going to go away. It’s a great product,’ noted the Cuyahoga Falls, Ohio-based Alside Window Systems’ Don Houston, senior technical service representative. ‘Vinyl siding is not going to go away. We just want to come up with a resolution that takes care of everyone.’”

Aug 27, 2010 11:36 PM ET

What's the "green building" advice concerning vinyl?
by J Chesnut

Please allow me to make a tangential remark.
An additional concern I have with the melting vinyl siding is if there are any toxic chemicals being emitted.
My "green building advice" about vinyl siding is don't use it. Call me an "absolutist" but what redeeming qualities does vinyl have other than its a profit making machine. There are always consequences to using any product that is designed to be the cheapest available option in order to underprice other options on the market. A writer for said it best when they said they would only start taking the vinyl siding industry seriously if their product recaptured the majority of its waste and recycled it for new product.
By most accounts vinyl siding does not have properties (other than it is cheap) that would make a contractor or designer recommend it over other siding options (other than it is one of several techniques to avoid solar driven moisture problems).
The production of PVC creates the very toxic vinyl monomer, PVC products leach heavy metals and maybe other chemicals, and when the vinyl siding makes it into the waste stream it is possible for it to be in a combustion environment that releases dioxins.
Toxicity doesn't seem to be a popular subject on this website. I think in principle when you go with the cheapest option the environment pays the difference.

Aug 28, 2010 5:39 AM ET

by Chrissy Marshall

Wow, this is the first time I have heard of melting vinyl siding.

This could not be a good situation for the manufacturers or for the manufacturers of the glaze either.

This is going to be interesting to see how this turns out.

Aug 28, 2010 11:22 AM ET

So the poor performance of
by James Morgan

So the poor performance of crappy siding is being blamed on the neighbors high-performance windows? This is, forgive me, insane. There are plenty of siding choices that can withstand these kinds of temperatures, and that are also way more beautiful & durable, don't brittle with age, don't contaminate workers' lungs in the manufacture process nor the landfill when (prematurely) dumped. Hell, if cost is an issue I'd rather use T1-11. When it comes to siding, no vinyl. That's final.

Aug 29, 2010 1:48 PM ET

Response to Robb
by Anonymous

In response to Robb, the window manufacturer I dealt with instantly admitted that their windows caused the melting of the siding and offerred to install screens at no charge to my neighbor. That is you first step to remedy this problem before even attempting to reside the house. Without the screens, the problem with reoccur over the winter months and will be visible come spring. Hopefully your neighbor is more receptive and cooperative than mine was when I approached her to discuss the issue.

Once your neighbor's full length screens are installed, then reside the house. That solved my problem and I even installed a vinyl fence, still no issues. So who is responsible? Is it the homeowner with the damaged siding, the neighbor with the low-e windows, the window manufacturer or the siding manufacturer? The way I handled it was to first approach my neighbor to work together to resolve the problem in a friendly manner, that didn't work. I then contacted the manufacturer of the windows, which extended the offer to install full length screens at no charge. The neighbor refused. Consequently, I filed suit against the neighbor to establish knowledge. Once you have knowledge of an act that is causing damage or harm and fail to cooperate to rectify the problem, liability (in my opinion) shifts to the neighbor. I filed a claim with my insurance carrier who resided the house twice, they in turn worked with the neighbors homeowner's insurance to get reimbursed. Last I heard, the insurance companies, jointly sued the window company who in turn looked to the homeowner for reimbursement since she refused to allow the screens to be installed. Had she done that the first time, she would have been releived of any liability, in my opinion. Ultimately, she installed the screens. My concern was that I would be dropped by my insurance carrier or my premiums would skyrocket, therefore, I did everything possible to make sure the insurance company was also protected. We also conducted a site survey which proved it was the windows. The reflection could be seen on the driveway and as the afternoon progressed, you saw the reflection go right onto the siding. The readings from the infrared thermometer read well into the 300 degree area!

The window and siding manufacturers, in my opinion, do have some degree of responsibility. The windows should not be sold and installed without full length screens as it is clearly evident that the reflection causes damage and potentially a fire hazard. Their product poses a risk that they assume.
I would state that the implied warranty of fitness for a particular purpose and/or an implied warranty of merchantability factors to the attorney that you are dealing with and see what their response is and rebutt it. You as the homeowner of the melted siding is innocent and to some degree, so isn't your neighbor. The manufacturer of the windows is primarily responsible and one can argue that the siding manfucturer is secondary since they market siding as indestructable, maint. free, etc and it should withstand "normal" environmental factors or specifically disclaim them when variables such as yours exist. Houses are being built closer and closer these days, glass is getting more energy efficient and the siding companies have to adapt their products accordingly to enviromental and technology changes. Hope this helps you!
Check out this link:

Aug 29, 2010 4:35 PM ET

to Anonymous
by James Morgan

I am glad that in your case the situation has apparently been resolved with the installation of screens, I assume these are standard removable external insect screens. This was a simple intervention that the window supplier could offer without significant cost (and probably without admission of liability) and I am pleased they did. It sounds as if your neighbor was reluctant to accept the screens, perhaps because of the reduction in view through the glass. If she or a subsequent owner chooses to take down the screens the problem could obviously re-emerge so you might want to consider getting a backup plan in place, perhaps using landscaping. I assume also that the windows in question are double-hungs or horizontal sliders. Casement windows which use interior insect screens would not be susceptible to this treatment so this would not be a fix for all situations.

Aug 29, 2010 6:41 PM ET

Yes, I do agree that the
by Anonymous

Yes, I do agree that the problem could re-emerge. Fortunately, it's unlikely that she is moving anytime soon and I don't foresee her taking them off as she realizes the potential implications. If there is a new owner, I would be certain to explain the problem/issue so they are aware and we can work together on any changes so it's mutually agreeable to both of us.

The windows are double hung windows and I'm not sure if the screens are removeable or not. Her refusal to install the screen on the top part of the window appears just to be difficult from the feeback the window company and the insurance company provided. Unfortunately, we sometimes get "bad" neighbors.

As far as landscaping, we are still looking for an evergreen that grows tall but not wide, suitable for being rather close to the house. I'm guessing it has to be an evergreen as it is in the winter months that the damage seems to occur. So far, so good but you raise good points!

Lastly, all three neigbors just removed trees and now I'm monitoring to see if my windows cause any problems with my other neighbor. I might have to install top screens as well and will do so gladly plus help out in any way possible to fix any damage.

Aug 30, 2010 3:04 PM ET

It is really interesting that
by Robert Hronek

It is really interesting that this is happening. On one hand if I plant a tree and it falls on the neighbors house I am not responsible on the other hand if her installs crappy vinyl siding he can force me to put ligt robbing screens on my house.

These must be some very small lots with homes close together to have this problem. Does anyone know at what distance the window and the siding are to cause the problem.

I almost think it should be up to the vinyl siding owner to protect his siding from the reflection. Plant a bush or create some other sun screen.

Aug 30, 2010 4:26 PM ET

Edited May 3, 2011 8:55 AM ET.

Response to Robert Hronek
by Martin Holladay

In my first article on this problem (an article that appeared in the April 2007 issue of Energy Design Update, this is what I wrote about the question of distance:

"Some experts note that vinyl siding must be 'just the right distance' away from a window to melt. In fact, cases seem to fall into two distinct categories. About half the cases involve what EDU calls a 'zap-the-neighbors' window, with the distance from the window to the melted siding measuring about 35 feet. The rest of the cases involve an inside corner of an exterior wall, with a window oriented 90 degrees to the melted siding; in such cases, the distance is usually less than 8 feet."

Sep 1, 2010 1:21 PM ET

The glare can cause other damage like breaking glass
by Dale

I live in the California high deser t. About four years ago I replaced the windows upstairs wilh gas filled duel pane windows. They work great however in the morning I can see the solar reflection outside on the fence or the front cap of my RV. Depending on the time of year the solar reflection will move and is very warm even 25 to 35 feet away from the window. I never gave it much thought Last week I moved the RV closer to the house to load it and the next day I found the RV bedroom window had a rather large crack in the lower pane ( The RV is a fifth wheel with thin smoked privacy glass). I called the glass man who said he would be out in 2 days. I taped the crack with scotch tape. The next day I found more cracks in the same pane taped them up. On the day the glass man was to come I wanted to check on the glass and found the upper pane was starting to crack. Where the RV was parked I was shocked that the window was breaking there is absolutely no reason for this to happen I've owned this RV for 5 years and had 1 other window crack in the kitchen (on the same side of the rig) 2 years ago. Then I noticed the solar reflection from the bedroom window upstairs on my house cross the window on my RV as the sun was rising. I took pictures because I have never heard of such a thing. With a portable temperature sensor I measured the side of the Rv , 63.1 degrees outside the reflection and 149.1 degrees in the center of the solar reflection. I have never heard of this before so I did a search on the internet and found the problems with vinyl siding. I guess I need to put solar screens on the upstairs duel pane windows. I believe there should be some disclosure of this problem when the duel pane windows are sold.

Sep 2, 2010 1:31 PM ET

Vinyl Siding
by Giles blunden

Terrific.... one more nail in the vinyl siding coffin.
Perhaps the end is nigh.

Sep 2, 2010 2:08 PM ET

Edited Jan 3, 2016 8:40 PM ET.

A letter from the Vinyl Siding Institute
by Martin Holladay

[Jery Huntley, the president of the Vinyl Siding Institute, sent me a letter which I hereby provide in full:]

Dear Mr. Holladay:
I’m writing in reference to your Aug. 27 post, “Window Reflections Can Melt Vinyl Siding.” When your nearly identical story first ran in the April 2007 edition of Energy Design Update, we felt that the article was reasonably complete and fair. Unfortunately, the current post suffers from factual errors and a lack of updating that could mislead your readers. We believe a correction is warranted.

First, your recent post alleged that information is “closely held by the vinyl siding industry” and that the Vinyl Siding Institute has “arranged for research on the topic” but has “not made their data public.” This is inaccurate.

As you noted in the 2007 article—but not in your recent post—VSI, in cooperation with several window manufacturers, arranged for laboratory research, which was in progress at the time. That study is now complete. VSI would be willing to release the information from the research, as we think it sheds light on the circumstances causing the problem. However, we are contractually prohibited from doing so without the consent of all parties, which has not been forthcoming. The Vinyl Siding Institute supports the release of the study and hopes that the other parties will comply.

Second, you used a 2007 quote from VSI’s Technical Director—in which he said that the solar reflection and heat distortion “phenomenon is rare”—to suggest that is inconsistent with the fact that manufacturers’ warranties exclude such damage. There simply is no correlation between the two.

Specifying that this cause of damage is not covered in a warranty says nothing about the frequency or likelihood of such damage. It simply reflects that this cause is beyond the manufacturer’s control and does not represent a defective product. For example, warranties also exclude damage from house fires. Few would argue that those exclusions are unreasonable. Vinyl siding is designed to withstand natural, everyday conditions, and if it malfunctions under those conditions, it would be covered by the warranty. But concentrated solar energy from reflected sunlight creates conditions far in excess of normal environmental exposure and has the potential to damage other materials in addition to vinyl siding.

Third, had you contacted us we would have been happy to review with you what we have learned over the past three years and provide you with updated resources worthy of your readers’ attention. For instance:
• The National Association of Home Builders (NAHB) conducted a thorough review of the issue and provided both technical background and discussion of remedial measures. You can obtain a copy of the NAHB review on our website; and,
• Currently, North Carolina state regulators are investigating window solutions to mitigate the hazard.

Our vinyl siding products—and more importantly, our customers—are most severely affected by the damage resulting from the solar reflection phenomenon. We welcome responsible discussion, research, and information-sharing that may lead to better methods of handling and avoiding the circumstances. We look forward to cooperating with you toward that end.

Jery Y. Huntley
President and CEO, Vinyl Siding Institute

Sep 2, 2010 2:13 PM ET

Response to Jery Huntley
by Martin Holladay

Jery Huntley,
Thanks very much for providing further information on this issue. I have corrected the article to accurately reflect the reasons that VSI has been unable to share the results of its research.

As far as the NAHB review of the issue is concerned, I did provide a link to that document -- in fact, in the article's very first line. However, the link may have been obscure, since I didn't identify the document as coming from the NAHB. Those who clicked on the link did see the NAHB document, though.

Again, thanks for providing further information on this topic.

Sep 2, 2010 5:27 PM ET

How close are we talking about?
by Bill

How close (or far away) do these windows have to be to cause vinyl siding to melt? Do I have to worry about a house built across the street? Or do I only have concern if I live in an area where homes are 10 feet apart on tiny lots?

Sep 2, 2010 7:40 PM ET

Edited May 3, 2011 8:57 AM ET.

Response to Bill
by Martin Holladay

The question you ask was answered in a post above, on August 30. But I'll repeat it:

In my first article on this problem (an article that appeared in the April 2007 issue of Energy Design Update, this is what I wrote about the question of distance:

"Some experts note that vinyl siding must be 'just the right distance' away from a window to melt. In fact, cases seem to fall into two distinct categories. About half the cases involve what EDU calls a 'zap-the-neighbors' window, with the distance from the window to the melted siding measuring about 35 feet. The rest of the cases involve an inside corner of an exterior wall, with a window oriented 90 degrees to the melted siding; in such cases, the distance is usually less than 8 feet."

Sep 3, 2010 11:43 AM ET

Vinyl Pirates
by John Leeke

At the risk of being dismissed, I think it is important to present the extreme alternate view to the notion that "vinyl is good and everyone should have it" that is promoted by the vinyl industry. This could be useful because an understanding of the root causes of the problem is needed to come up with an effective solution. I believe my opinions and views presented here show just a much respect for the vinyl industry as it shows to homeowners with all its misleading marketing, finger pointing and secret keeping.

The reflective melting issue is just another good example that reveals the true intentions of the vinyl pirates and their corporate masters. They have one single purpose, which is to get their hooks into the pockets of homeowners and remove as much money as possible. In fact, federal and state law limits them to this singular purpose of grabbing money for their share holders. They have no true interest in helping homeowners take care of their homes, which is why they have to spent millions of dollars for marketing to convince homeowners to buy their cheap plastic products. One way they can sell their products so cheaply is that they "externalize expenses" such as the cost of environmental and health damage directly caused by their products.

There are traditional building materials that are effective and even low-cost over the long-term. It is well known and proven with centuries of solid evidence how materials like wood, paint, stone and bricks can be maintained over the long-term at low cost by local tradespeople and DIY homeowners. This has the added benefit of keeping more building maintenance money in the local economy, instead letting the corporations suck that money into the corporate coffers where it will never been seen again.

John Leeke

Sep 6, 2010 8:47 AM ET

I agree with one of the above
by David B

I agree with one of the above comments. Blaming high-performance windows for damaging an inherently cheap product is ludicrous. If contractors/home-owners factored in the true costs and risks of installing vinyl siding they may be less likely to install it.

Sep 6, 2010 10:34 AM ET

3 types of heat
by Brian B

On Aug 27 Doug mentioned foil backed insulation as a possible culprit and it was promtly shot down as being able to contribute. I think we need to review this once more when we look at how heat is transfered. There are three means of moving heat, Convection, conduction and radiation.

The heat transfer method we are dealing with in this issue is radiation. All radiant heat does not stop when it hit the first surface, some of it penitrate the surface and could then be reflected back into the siding. if this is not true then there should be no reason to use foil faced product anywhere in a house.

Being an engineer that has set up experiments to test products, sometimes a little change like the type of insulation or if there is a fan in the room, can change a product from being acceptable for all application and being a complete failure.

Sep 6, 2010 12:12 PM ET

Foil-faced sheathing
by James Morgan

Given the patterning effect visible in the photographs I doubt that foil-faced insulation is primarily responsible in these instances. I suspect though that reflective foil may well contribute to premature failure of vinyl siding in other ways by rendering it brittle and more liable to general mechanical damage. We have seen many instances of wood siding affected in this way: in an exterior remodel our contractors often try to save sections of the original siding for patching purposes but if foil-faced sheathing has been used the boards will generally shatter as they are removed.

Sep 6, 2010 12:28 PM ET

Vinyl siding melting
by Dave H.

We purchased our new home in December, 2004, in central Indiana. Didn't notice any problems with the vinyl siding distorting at all until January or February of 2008, even though the house to our north was built in early 2005. I am sure the sun must have shone brightly sometime during that 3-year period. The melting problem may be "rare", but it must happen often enough that CertainTeed could recognize it merely by my written description of the damage and photos sent with my original e-mailed warranty claim this year. CertainTeed refused to send someone to inspect the damage, and also refused to inform me of the name of their Customer Service Manager. I have never noticed reflections from the neighbor's windows myself, but I would guess that any would occur during the winter months when the sun is low. My neighbor's house is about 15 feet from my house in the rear, and 20-25 feet in the front - the houses are not parallel.
I have seen 2 other houses in our subdivision with the same type of melting. Both other houses also have CertainTeed vinyl siding, and both were built in 2004 or 2005.
The value of my house has been adversely affected through no fault of my own, and really through no fault of my neighbor. Since I have received absolutely no consideration from CertainTeed, my next step will be to contact local media outlets for assistance.

Sep 6, 2010 2:11 PM ET

Window Reflectance and Vinyl Siding
by Gary Gentry

As the owner of a Raleigh Home Inspection firm in Raleigh, NC, and a veteran Home Inspector, I can attest to the fact that we do indeed see this phenomenon on a somewhat routine basis. I don't think one could describe the occurrences as "rare" although we certainly are not seeing it in any high percentage of inspected homes. It does, though, seem like we are seeing it a bit more frequently as more "high-tech" windows are coming into the marketplace and are being installed in new homes.

The phenomenon is most definitely an interesting one as evidenced by this informative article and the ensuing comments/discussion. It was interesting enough, from a Home Inspection perspective, for us to do a simple, brief InspectBits video relating to the melting of vinyl siding (and by no means or stretch of the imagination is it intended to be an intensive assessment of the issue); the video can be viewed at .

My "take" on the situation is that it is a simple (or maybe not so simple...) matter of physics and technical progression...bring together any particular combination of technology, materials, systems, components, and proximity...and there may be issues...especially when the Sun and Mother Nature are directly involved.

I can relate to the homeowner who has windows that are reflecting energy onto the property of others ...and as well with the position of the owners of homes that are experiencing damage to their siding. Unfortunately, there are those that will take any opportunity to speak badly about any product (pick one). It may be the " I have an issue therefore someone must be to blame" syndrome; or it could be that nothing is ever going to make everyone happy. I am neither a proponent, or an opponent of vinyl siding...based on my observations, experience, and knowledge of the product, and as with any other wall cladding material, if it is installed correctly and with a reasonable attention to detail, then it performs as advertised and as intended. I have yet to see any type of exterior wall cladding (not cement-based fiber siding, not brick veneer, not stone veneer or simulated stone veneer, not EIFS, not vinyl siding, etc.) that, at some time or another, I haven't directly observed to be installed in an improper and deficient manner and where there were problems related to the installation. But this subject issue is, admittedly, a bit different

It is a noted positive that the various directly concerned entities (VSI, NAHB, siding and window manufacturers) seem to be interested in developing reasonable solutions to the issue. It will be interesting to see whether or not the solutions can be agreed upon directly by the players or whether the solutions will be legally mandated through the court system...hopefully, that won't be necessary on any large scale. I don't think, though, that I'll be holding my breath on that one given the current environment concerning tort law, product liability law, and the eagerness of attorneys to bring and promote such actions.

Screens and shrubbery positioning seem to be inexpensive and reasonable solutions with the screens being the more "permanent" of the two.

Thanks, GBA and Mr. Holladay, for an informative article and for allowing a lively discussion in this forum.

Gary Gentry
Quality Residential Inspections, Inc.
Raleigh, NC

Sep 6, 2010 4:11 PM ET

Response to Brian B
by Martin Holladay

Radiant energy is stopped by any opaque (solid) object. No radiant heat energy passes through vinyl siding. What happens is the radiant energy hits the siding; then the siding softens and melts. But radiant energy cannot pass through the siding and magically hit the foil-faced siding behind it. The foil-faced siding is always in the shade and never sees any radiant energy from the sun.

Sep 6, 2010 5:41 PM ET

The vinyl industry must change as everyone else has..
by Lou Cosme

The vinyl industry must change as everyone else has. The window manufactures must conform to newer mandates every other year or so as well as others in the building trades and product suppliers. The traditional low melting point of vinyl must move to a resonable level and window manufacturers should design outer panes in widows to deform less due to atmospheric issues. In the end, however, it is clearly the burden of the vinyl siding industry to produce a better product that keeps up with modernity and its shortcomings. I cannot see a logical way around this issue for the vinyl industry.

Sep 6, 2010 9:32 PM ET

Just a thought
by Anonymous

It may just be me but I think the real problem is that THE HOUSES ARE TOO CLOSE TOGETHER!!
With houses ~8ft apart no wonder the siding melts.

Sep 6, 2010 11:43 PM ET

Mr. Gentry
by noah

"...homeowner who has windows that are reflecting energy onto the property of others"

Sep 7, 2010 12:46 AM ET

Mr. Gentry identifies the party initially responsible...
by noah

"...homeowner who has windows that are reflecting energy onto the property of others"

I am responsible if rain-runoff from my property causes damage to my neighbor's property. As much as I hate to admit it, I would also be responsible if I was reflecting solar energy onto my neighbor's property and causing damage. I would consider the Builder of a subdivision responsible to the homeowners.

Sep 7, 2010 8:57 AM ET

random thougths
by Anonymous

The exterior screens solution assumes full screens on double hungs. What if the windows were sgl hung with half scrrens, or casement/awning with interior screens or picture windows with no screens?
Since the coating(s) in "Low-Emisivity" glass reflect radiant heat . . .rather than wait for trees & shrubs to grow . . . would a quicker solution be to install some type of solar panels where the heat build-up is worst?
Would more space between the houses help? Of course that would require larger building lots.

Sep 7, 2010 9:01 AM ET

Response to Anonymous
by Martin Holladay

1. You're right that the insect screen solution only works for full screens on double-hung or slider windows.

2. Adding any kind of film to the window depends on cooperation from your neighbor.

3. Yes, moving the house farther away would work. That is almost never the most cost-effective solution, however. House moving is expensive -- and requires a large lot.

Sep 7, 2010 10:19 AM ET

Yes the problem arises in more urban areas
by Lou Cosme

You cannot escape the issue in urban areas. The house spacing which accounts for density is an issue. Since the vast majority of the population lives in urban locations, there has to be a solotion. The vinyl industry must adapt or start losing market share to more resiliant prodcuts where this is not an issue, there is no way around it.

Sep 7, 2010 11:20 AM ET

Vinyl Manufacturers knew about this
by Robb K

Thanks for the information Anonymous, regarding your melting siding story. I have yet to look into the negihbor's window manufacturer. I continue to deal with the siding manufacturer.

One remark I have regarding Gary Gentry's comment. There may be those with the thinking " I have an issue therefore someone must be to blame" syndrome, he mentioned. In these cases, however, homeowners dealing with melting siding should not be lumped into this group. As a homeowner purchasing vinyl siding and the warranty that comes with it, I was never advised about this phenomenon. The Vinyl Siding Institue (VSI) knew about this and put out a statement in 2002. This is what the manufacturers then send out once you make a claim.

My point is that the average homeowner would never know about this phenomenon when purchasing vinyl siding. We would know about accidental fire or arson damage, tornadoes, etc. This is an issue of failure to notify the homeowner. Vinyl manufacturers need to put this phenomenon in their warranties as an exclusion, thereby notifying the homeowners.

Sep 7, 2010 11:41 AM ET

Response to Robb K
by Martin Holladay

Robb K,
You wrote, "Vinyl manufacturers need to put this phenomenon in their warranties as an exclusion."

But they do -- and they have for years. See the sidebar to the article above.

You may think that such warranty exclusions are a useful method of notifying homeowners, but many other purchasers of vinyl siding think that the small print is actually a way for manufacturers to weasel out of responsibility for a known problem.

Sep 7, 2010 4:46 PM ET

Response to Martin
by Robb K

My warranty did not specify this phenomenon in the original warranty. Interestingly though, they updated the warranties on the website where it specifically mentions siding that has distorted or melted due to exposure to excessive heat sources (including but not limited to reflections from windows).
I agree the small print is a way for the manufacturers to avoid responsibility, however, in my personal experience it was not even mentioned until after I made a claim and was persistent.

Sep 7, 2010 10:30 PM ET

How to tell which manufacturer is at fault - the industry future
by MrW

Window manufacturers will be found liable in suits when the window can be shown to concentrate sunlight. Vinyl siding manufactururs will use reflective coatings to prevent overheating, and will be rated by melting temperature. Eventually all vinyl will be required to meet minimum standards such as: absorb the amount of energy generated by a single clear pane glass, progressively more reflective surfaces. In situations where the window or door surface causing the over heating does not concentrate sunlight, the siding in question can be said to be improper for the geographic area or application. If the siding is marketed as all weather or all purpose the vinly siding manufacturer can be held responsible for replacement and remediation of the problem. One solution for this problem which could be instituted in a recall process would be the application of reflective coatings.

Sep 15, 2010 7:49 PM ET

Neighbor Not Required
by Mike A

I experienced melting vinyl siding without the help of a neighboring house. The windows from my living room and breezeway were reflecting light onto the siding on my attached garage, directly across from my living room. The house is ranch style, not an exotic Victorian, but not a shoebox either. The house was built 55 years ago and vinyl sided 5 years ago.

- I had the siding replaced once, then the issue came back a few months later.
- I applied tinting to nearby windows. This lasted more than a few months, but the issue eventually came back. The tinting was obnoxious..... really darkened the inside of 2 rooms.
- I tried some plants, but this is impractical in New England, where they can not survive the winter outside. There is cement by the windows as well as the garage, so permanent shrubs were not an option.
- Finally, I had the damaged area replaced with wood clapboards, cut to size. Fortunately it was not a large area.

Warranty or not, there is no way that the average consumer can expect this type of aggravation. The vinyl industry needs to improve the product in a big way, or else the media needs to become more involved (I have started to see stories of melted siding on the news from Boston).

Sep 29, 2010 2:42 PM ET

Do the plants live?
by Lynn Johnson

If you plant shrubs and/or trees to break up the surface of the siding, do the plants live or do they cook like the siding? I am a landscaper and have a client that has asked about plantings. If I plant the shrubs, will I be able to give him our 1 year guarantee?

Sep 29, 2010 3:04 PM ET

Response to Lynn Johnson
by Martin Holladay

I'm just guessing here, but it would seem that the plant would be at a different distance from the problematic window than the siding, changing the focal length. Because of that, the light should not be as intensely focused, and I imagine that plant will survive.

If it's a sun-loving plant, it might even thrive.

Sep 29, 2010 3:51 PM ET

My house too!
by Fred

I'm glad I saw your article. When I first saw the first section of my house "melting" I was concerned, but when I found a second spot this summer, I got upset. Both parts of my house are facing northwest. The siging is gray, and being much darker than cream could play a part in it. At first, I was unsure what was causing it, but now know that my rounded, 5 sided kitchen nook area, jutting out and having windows on each flat side, is creating an area where being at a 90 degree angle to the siding, is reflecting more heat energy to those spots. We are looking at putting large potted plants and anything else we can think of to block the direct from the sun and reflected from the windows energy. I say that this IS a defective product. Manufacturers should know that conditions like this would be common, especially in areas of the country where summer days exceed 90 degrees with bright sunlight and shouldn't cover a house with something that "can't take the heat". Buyer beware.

Sep 30, 2010 8:30 AM ET

Guests burned by window reflections at Las Vegas hotel
by Martin Holladay

Here's the latest news story: sunlight reflecting off the windows of a new Las Vegas hotel is melting plastic garbage bags and causing severe burns to guests sunbathing by the hotel pool.

That's scary. The news story has a catchy headline:
Las Vegas hotel guests left with severe burns from 'death ray' caused by building's design

Oct 5, 2010 10:49 PM ET

Melting truck mirrors
by TomC

This is a link to a GM truck forum where I posted an inquiry about melting mirrors. My outside mirrors on my truck have melted twice. I believe solar reflection from my windows caused it. Pictures of the damage are posted. FYI.

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