Heat damaged vinyl siding (C) Daniel Friedman Sun or Reflected Heat as Cause of Buckled Vinyl Siding

  • VINYL SIDING DEFORMED by SUNLIGHT- CONTENTS: in certain cases intense sunlight or reflected or concentrated sunlight and heat from nearby reflecting surfaces causes vinyl siding to appear bent, buckled, loose, or otherwise damaged
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Heat & reflected sunlight as causes of vinyl siding damage:

Heat from intense sunlight or from reflected sun and heat from nearby windows or other surfaces can cause buckled, rippled, bent, deformed, loose, or un-clipped vinyl siding. This article documents those effects, conditions, and apparent causes.

This article series discusses all of the known causes of buckled, loose, cracked or otherwise damaged vinyl siding. Rippled or loose vinyl siding may be more than just a cosmetic worry, and may indicate structural defects, building movement, leaks, or even heat or fire hazards. Our page top photo shows wrinkled vinyl siding - often caused by heat exposure but in this case the extent, location, pattern and size of the damage made us suspect that there was another cause, as we explain below.

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Vinyl Siding Deformation Reflected Sunlight & Heat from Nearby Surfaces,

Originally we thought the product at right was defective, or that it may have been damaged by a solvent. But it is difficult to imagine that defective siding would have been cut and installed with the rippled effects in such a regular pattern.

Heat damaged vinyl siding (C) Daniel Friedman

[Click to enlarge any image]

Heat damaged vinyl siding (C) Daniel Friedman

Buckled Vinyl Siding Suspected Due to Sunlight: Pennsylvania

Sun-buckled vinyl siding over a deck on sunny side of home (C) JR Sun-buckled vinyl siding over a deck on sunny side of home (C) JR

Reader comment: Buckled siding attributed to heat reflected off a deck

... the warped siding that might be related to the orientation of the wooden deck relative to the siding. The siding in question faces directly east. and am located just north of Philadelphia. This time of year, the morning sun hits the deck and siding.

You can see the warping on the siding with the deck boards perpendicular to the siding whereas, the other siding has no warpage and the boards are parallel to the house. I really believe it has something to do with the sun's rays reflecting off the deck Other sides of the house are ok. - Schmitty, 2016/06/22 by page bottom comment & private email

Sun-buckled vinyl siding over a deck on sunny side of home (C) JR

Oddly the worst buckling appears to occur at the siding course end-laps between sections. From additional correspondence among the building owner, editor, and Alan Carson we note the following:

Buckled Vinyl Siding Research including the Effects of Sunlight on Vinyl Siding: Buckling, Bulging, Curling

Question: diagnosing why there is rippled odd looking vinyl siding - traced to reflected sun-heat

The picture with the dryer vent below the window (see Buckled, Rippled, Deformed Vinyl Siding Caused by Other Hazards: heat leaks, chemical spills, unknown above) was caused by the reflection of the sun off the window. I would put $$$ on it. - Jim Hilt 9/11/2011

There's a good chance the rippled effect on the siding was caused my improper dryer vent installation and hot dryer air is leaking behind the siding. - Anonymous 9/15/2012


Thanks for the guesses, Jim and Anonymous.


Interesting in this case, you'll see that the rippled vinyl siding extends way below the opposing window - not in the immediately-obvious path of reflected heat from the window glass.


We have expanded our discussion of the rippled vinyl siding effect to explain the difference between obvious heat damage from a barbecue grill and the odd rippling in our photo discussed above. The vent you saw is not for a hot air dryer, it's an air intake for a fireplace insert built into that chimney chase. But your guess is a good one in that there may be a more dangerous hot gas leak from the fireplace. For that reason we recommended invasive inspection to check the chimney chase interior as well as the condition of the fireplace

For additional photographs and discussion of all types of sagged, torn, cut, broken, rippled, or otherwise damaged vinyl siding, take a look at these subtopics found in the article above, starting at VINYL SIDING BUCKLED WARPED

Reader Follow up / Comment: Vinyl Siding Rippling Caused by Sunlight & Heat Reflected from Nearby Windows

The picture with the dryer vent below the window was caused by the reflection of the sun off the window. I would put $$$ on it. - Jim Hilt 9/11/2011

... - you'll see that the rippled vinyl siding extends below the opposing window - not in the path of reflected heat from the window glass . - Ed.

On the contrary! As the sun rises in the sky, the reflected light and heat move downward on the wall. That softening pattern is exactly where it should be. When the window and adjacent wall are so close together (and always facing south and west), no breeze carries the hot air away.

Between the direct sun and the reflected sun, you get high temperatures on the surface, but it's rare to see damage from it, because usually airflow cools the surface off. When you put them too close together like this (and again, oriented to the sun just-so), the pocket of dead air allows temps to get even higher and you see the damage shown. - Mike in Michigan 11/28/2012


Thanks so much, Mike! We are so grateful for your very interesting explanation of our "mystery" rippled vinyl siding. Your analysis looks very reasonable & sound to me. Though I needed to see the careful reasoning in your comment, now I'm convinced.

Indeed this side of this home faces roughly South and the side of the facing chimney chase was indeed, in some weather, a hot, dead-air space.

We will look for other examples of the case you describe and would welcome photos of this vinyl siding damage type from other readers. (Use the CONTACT US link found at page top or bottom to send us email & photos)

We appreciate your taking the time to comment: working together we are smarter than anyone. - Daniel

Reader Question: buckled siding from reflection from self-cleaning windows?

(Sept 26, 2014) Bill said:
Has anyone heard of vinyl siding buckling due to reflecting from self cleaning windows


Moderator said:

Yes Bill, we have reported on buckling vinyl siding from heat reflected from nearby windows. The fact that windows are "self cleaning" is not a gating consideration it's reflection of heat and sunlight off of glass.

In the article above in the section titled "Vinyl Siding Deformation Caused by Other Hazards: heat leaks, chemical spills, reflected sunlight & heat from nearby surfaces, or unknown" you can read about this phenomenon and see photo examples of its occurrence.

Anonymous [apparently a window vendor - Ed] said:
The number one dissatisfaction with vinyl siding is the warping and buckling. The reason for this 99.9% of the time is installation. Vinyl siding is a great product overall and now there is a guaranteed fix for the warping and buckling that occurs during temperature changes. The Glide-Lock Siding Hanger can be used with over 96% of all vinyl sidings, easy to use, low cost and proven effective. In fact warping and buckling is covered under the lifetime Written Warranty.

(Feb 12, 2015) Richard Brow said:
I have the same issue with Deformation of siding. According to CertainTeed originally it was from the window reflection. After that it was the roof. Then the skylight.
CertainTeed came out and replace a small area (2 months after it was installed)and did not last. They can't tell me what caused it and refuse to repair. No lifetime warranty just lip service.



If you like, find our email at the CONTACT link at page bottom and send me some photos for further inspection and comment.

Article Series Contents


Continue reading at VINYL SIDING BUCKLED RIPPLED COMBINED EFFECTS? or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see VINYL SIDING BUCKLED WARPED - first in this article series

Or see SIDING VINYL - home

Or see THERMAL EXPANSION of MATERIALS for a table of CLTE values for common building materials



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VINYL SIDING DEFORMED by SUNLIGHT at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


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